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Lab Manual v1.2013

1. task that keeps decrementing a global counter __task void task4 void GLCD DisplayString 6 U l1 Task 4 for 77 1 g COUDLSIZ j if g counter2 0 g counter2 60 reset os dly wait 100 BPPIDLPALSEUL Detter SO wr BOnUDer2 g GLUD Digplaystring 6G Y Vly Inte _ text DUITSE initialization task that spawns all other tasks tesk void 1inrtivord OS tek oreate taskl lip 77 task L SL prioriry 1 0s tak Greareitaek2 Iie Jy task 2 BL priority 1 oe Lek Create iaeks Ty 77 task 2 t priority l Os tsk create task4 1 7 7 task 4 at priority 1 os tsk delere selr j task must delete itself before exiting 72 int main void 1 initialize the LPCl7xx MCU SystemInit 2 initialize GLCD and LED LED init0j GLCD Init LED on 0 turn on LED 0 at P1 28 GLCD Uleeri re low 7 GLOCO Displayetring 0 Uy ly RIX Hello World 22 7 ye 3y initilize the OF and start the first task OS Sys INICI DIL 73 Lab 7 Introduction to Ethernet 1 Objective The objective of this lab is to introduce you to Ethernet We also study the EMAC EasyWEB example from Keil which illustrates a simple web server hosted on the MCB1700 board Note This presentation has been adapted from various references listed at the end of this lab 2 Ethernet Ethernet is now the world s most pervasive networking technology History In 1973 Xerox Corporation s Palo Alto R
2. which is 48 in HEX stored in register R3 1s going to be stored to memory location 0x4001000 stored in register R4 which if you look on page 320 of the user manual you will see that it is register LPC UARTI gt THR Registers Dn Disassembly 135 while i iUARTiTxEmpty amp OxO1 Looe BD D nnnnpon OxO0000258 45606 LDR r3 pe 44 HOxo0000286 R1 ow2007 0005 a xaaagngog25 781B LDRB r3 r3 0400 z R2 D npannon OxOo000025 F is FD01 TST r3 0x01 a R3 D Dnnnnn48 OxOo00002z60 DpOFA BEQ OxO00000258 137 LPC UART1 THR BufferPtr 2 a R5 D DDppSAn OxOO0000262 780B LDRB ra ri 000 S RE On 2345678 Oxooo0002z64 4c04 LDR r4 poe 16 HOxo00002 76 R7 D nnnnnonn c 0xangnnnz 66 6023 STR ra r4 0400 aW F S Ra De4DD2r nno 138 UARTLTxEmpt Bi f not empty in the THR until i S H3 0100001 DC ia R1 Ds OC SA A F m F z num TE system LPC17xx c E nmm t RTI Ox00000000 I CUL Ri D EDDDEDDD 2 _ R13 SP DADODOTFS po TRE status contain valid data 2 R14 LR D DDDOPBE while HUARTiTxEmpty amp OxOli LPC UART1 THR BufferPtr i PSF 021000000 UARTLITxEmpty 0 f not empty in the THR until it Baked ButterPtr Speler Length El Internal fertis kA Thre Figure 1 Illustration of the moment when H is placed into register 0x40010000 26 S Example 3 Blink LED using Timer 0 Interrupt The file necessary for this ex
3. ARM Compiler toolchain for uVision Particularly browse ARM Compiler toolchain for uVision Using the Assembler ARM Compiler toolchain for u Vision Using the Linker http nfocenter arm com help index jsp topic com arm doc dui0377c index html Professor J W Valvano UTexas resources http users ece utexas edu valvano V olume 1 uvision UWaterloo ECE254 Keil MCB1700 Hardware Programming Notes https ece uwaterloo ca yqhuang labs ece254 doc MCB1700_Hardware pdf EE 472 Course Note Pack Univ of Washington 2009 http abstract cs washington edu shwetak classes ee472 notes 472_note_pack pdf Chapter 6 APPENDIX A Some info on LPC1768 peripherals programming Pins on LPC1768 are divided into 5 ports indexed from 0 to 4 Pin naming convention is Px y where x 1s the port number and y is the pin number For example P1 29 means Port 1 Pin 29 Each pin has four operating modes GPIO default first alternate function second alternate function and third alternate function Any pin of ports 0 and 2 can be used to generate an interrupt To use any of the LPC1768 peripherals the general steps to be followed are 1 Power Up the peripheral to be used 2 Set the Clock Rate for the peripheral 3 Specify the pin operating mode Connect necessary pins using Pin Connect Block 4 Set direction Initialize the registers of the peripheral 1 Power Up the peripheral Let s assume we are interested in utilizing the pin P
4. EPF else if IIRValue IIR CTI Character timeout indicator eae else if IIRValue IIR THRE THRE transmit holding register empty 20 TY See in Table 276 on page 303 in the User Manual what is the meaning of the three bits 1 3 from the original IIR register 011 1 Receive Line Status RLS 010 2a Receive Data Available RDA 110 2b Character Trme out Indicator CTI O01 3 THRE Interrupt For each of these situations something else is done inside the corresponding branch of the if instruction above In other words we first identify the interrupt and for each ID we do something else If none of the expected IDs is found we do nothing Please take your time now to explain what s done in each of these cases Read pages 303 304 in the User Manual for this This is very important in order to understand the overall operation of the example of this lab 4 Lab Assignment 1 not graded and should not be discussed in the lab report Use a Debug session to step through the execution of this program The scope is for you to better understand its operation See lab 1 for how to use run a debug session See also documentation of the code bundle from NXP 7 2 Answer the question Why did we need to remove the ISP and RST jumpers in Example 1 3 Describe in less than a page typed font size 11 single line spacing all instructions inside the function void UARTO IROHandler void for each of the
5. Layer 2 of the seven layer OSI model is a frame and at Layer 4 the Transport Layer the correct term is a segment Hence e g a TCP segment is carried in one or more IP Layer datagrams or packets which are each carried in one or more Ethernet frames though the mapping of TCP IP and Ethernet to the layers of the OSI model is not exact as we ll discuss in the next section Some prefer to refer to all these simply as network packets Network packets are described like Russian dolls a k a Matroishka An IP packet resides within an Ethernet packet A TCP packet resides within an IP packet A HTTP packet resides within a TCP packet See figure below for an illustration of this point Ethernet Packet Receiver Sender Mumber Data M C address MAC address of bytes IP Packet v IHLI tos L Ip FL fol ttl Prat cHs 28 nder Recelver Data IP address IP address TCP Packet Sender Receiver e m o Figure 6 TCP packet or segment vs IP datagram or packet vs Ethernet packet or frame A network packet is nothing more than a chunk of data that an application wants to deliver to another system on the network This chunk of data has information added to the front and back that contains instructions for where the data needs to go and what the destination system should do with it once it arrives The addition of this routing and usage information is called encapsulation The figure below illustrates the
6. Of course to turn off a particular LED just replace FIOSET with FIOCLR in the above code Note we can also set HIGH LOW a particular output pin via the FIOPIN register We can write specific bits of the FIOPIN register to set the corresponding pin to the desired logic value In this way we bypass the need to use both the FIOSET and FIOCLR registers However this is not the recommended method For example in the case of the blinky example we use the following C code LPC_GPIO1 gt FIOPIN 1 lt lt 29 make P1 29 high LPC _GPIO1 gt FIOPIN amp 1 lt lt 29 make P1 29 low b The pin is set as input We read the current pin state from FIOPIN register The corresponding bit being 1 indicates that the pin is driven high The corresponding bit being 0 indicates that the pin is driven low The FIOPIN is a member variable defined in LPC GPIO TypeDef C struct One normally uses bit shift operations to shift the LPC GPIOx gt FIOPIN value to obtain pin value s Refer to Section 9 5 4 in the LPC17xx User s manual for details For example to read the joystick position the following code can be used define KBD MASK 0x79 uint32 t kbd val kbd val LPC_GPIO1 gt FIOPIN gt gt 20 amp KBD MASK When the joystick buttons are inactive the bits located at P1 23 24 25 26 are logic 1 When any of the joystick buttons becomes active the bit corresponding to that pin becomes 0 APPENDIX B Listing of blinky3 s CopyLeft Cr
7. in the downloadable archive of files for this lab Note With this approach one does not need the ULINK2 programmer debugger b Brief program description Looking at the main function inside the uarttest c file we can see the following main actions UARTO and UARTI are initialized UARTInit 0 57600 baud rate setting UARTInat 1 57600 baud rate setting A while loop which executes indefinitely either for UARTO or for UARTI The instructions executed inside this loop let s assume the UARTO are 16 e Disable Receiver Buffer Register RBR which contains the next received character to be read This is achieved by setting all bits of the Interrupt Enable Register IER to 0 except bits THRE and RLS In this way the LSB 1 e bit index 0 out of 32 bits of IER register is set to 0 The role of this bit as explained in the LPC17xx User s Manual 1 on page 302 when set to 0 is to disable the Receive Data Available interrupt for UARTO e Send back to the host the characters from the buffer UARTOBuffer This is done only if there are characters in the buffer the total buffer size 1s 40 characters which have been received so far from the host PC The number of characters received so far and not yet echoed back is stored and updated in UARTOCount e Once the transmission of all characters from the buffer is done reset the counter UARTOCount e Enable Receiver Buffer Register RBR Thi
8. 34 33 32 31 28 27 1211 87 aa 0 0 Version Check Pattern in idle state erase reset illegal command CRC error erase sequence error address error parameter error Figure 7 The format of the 40 bit Response The steps necessary to complete the SD card initialization are shown in the flowchart in Fig 8 The flowchart consists of boxes in which a command number is specified Starting at the top of the flowchart each command has to be sent to the SD card and a response has to be received In some cases a response from the card needs to be processed to decide the next course of action as indicated by the diamond shaped decision boxes This 1s just one example of such an initialization sequence credit ftp ftp altera com up pub Altera Material 12 0 Laboratory Exercises Embedded Systems DE2 embed la b9 pdf from where portions of this discussion are adopted It s possible that it may work or not depending on the type of card you use and on its manufacturer Other similar such flowcharts exist for example http elm chan org docs mme sdinit png Most of the times you will have to try to implement several of them until you will get it to work unless you use a known card and an already written program for that card 59 4 Capacity C Card Capacity Figure 8 Flowchart of a generic SD card initialization routine in SPI mode C FAT File system basics Microcontrollers are relativ
9. I2CD0IBit 33 T2C1InIt 43 lo202lInibt J 4 LPC SC PCONP 1 lt lt 15 LPC_GPIOO gt FIODIR 1 lt lt 21 1 lt lt 22 LPC GPIO0 FIOCLR 1 lt lt 21 LPC GPIO0 FIOSET 1 lt lt 22 5 NunChuck phase 1 search for i2c devices debug only purposes NunChuck phasel znit Note Be careful with dirty fixed delays realized with for loops From device to device or even same device with different write length or various I2C clocks such delay may need to be changed however it s good to have a break point between phases 6 for ever loop while 1 lf ia gest stuff for 1 0 1 lt BUFSIZE i44 4 I2CSlaveBuffer PORT USED 1 0x00 b NunChuck phase 2 NunChuck phase2 read Nu nChnck translate data NunChuck print data c re draw the circle to mimic movement if necessary Note joy x axis joy y axis have values in range 30 230 with mid range value of about 130 when the joystick rests implement the simplest method to move the circle around whenever joy x axis 190 230 upper values in its range keep shifting the circle to the right jj whenever joy x axi15 30 70 lower values in its range keep shifting the circle to the left gt whenever joy x axis is in the mid range do not move circle 44 apply same logic for joy x axis TODO assignments move the circle based on the rotations i e d
10. UART modified with the ones provided in folder example2 of the downloadable archive of this lab We make this copy and work inside keil examples to avoid copying files from keil examples common such as type h Launch uVision and open the project from UART modified Build the project and download to the board as you did in lab 2 Use a Putty terminal or a HyperTerminal if you use Windows XP to see that indeed Hello World is printed out 25 Simulation Debug 1 Configure the debugger to Use Simulator 2 Click Debug menu option and select Start Stop Debug Session 3 Select View gt Serial Windows gt UART 2 In this window we can see what is sent out from UARTI 4 Select View Watch Windows Watchl Double click on Enter expression inside the newly opened window and type UART1TxEmpty This will monitor the variable UARTI TxEmpty 5 Run and Step through the program simulation Observe and comment Target Debug 1 Configure the debugger to ULINK2 ME Cortex Debugger 2 Modify the following line inside uart c volatile usnbo2 t UABTICOUBML 1j We do this so that UARTI will transmit only one character which we want to observe during debugging 3 Build and download 4 Click Debug menu option and select Start Stop Debug Session 5 Run and step through the execution of the program Observe and comment Identify the moment when the execution is in the state shown in the figure below This is the moment when character H
11. a lot of online information on SPI You should search and read some for more details Good starting points are the references suggested in 1 from where most of the above material has been adopted Also read Chapter 17 of the LPC17xx User Manual for details on the SPI interface available on the LPC1768 MCU that we use in this course 3 MMC and SDC Cards A Background The Secure Digital Memory Card SDC is the de facto standard memory card for mobile devices The SDC was developed as upper compatible to Multi Media Card MMC SDC compliant equipment can also use MMCs in most cases These cards have basically a flash memory array and a micro controller inside The flash memory controls erasing reading writing error controls and wearleveling are completed inside the memory card The data is transferred between the memory card and the host controller as data blocks in units of 512 bytes therefore these cards can be seen as generic hard disk drives from the view point of upper level layers The currently defined file system for the memory card is FAT12 16 with FDISK petitioning rule The FAT32 is defined for only high capacity gt 4G cards Please take a while and read the following very popular webpage that describes the use of MMC and SDC cards http elm chan org docs mmc mmce e html A lot of the concepts described in the aforementioned webpage apply also to working with micro SD cards which we ll use in the examples
12. a network or changing network settings 4 TraceRT Tracert or traceroute is a command that shows the path that packets of data take while being sent It s handy for checking to see where a possible network failure lies or even for ensuring that data packets are taking the fastest route possible on a network 5 FTP TFTP FTP and TFTP are both used for transferring files It is important to note that FTP is a TCP utility while TFTP is a UDP utility TFTP tends to be less secure than FTP and is generally only used for transferring non confidential files over a network when speed is concerned 6 Hostname Hostname is a simple command that displays the hostname of the current computer simple yet effective 7 Whois Whois information is just like an online phonebook It shows the contact information for owners of a particular domain By using a Whois search you will find that Google is based in California APPENDIX C Key Features of TCP IP Five of the most important features of TCP IP are a Application support 88 b Error and flow control c Logical Addressing d Routing e Name resolution a Application Support Assume you are multitasking you are uploading files to your website sending an email streaming music and watching video all at the same time How does the computer know where to send each packet of data 1f multiple applications are running We sure wouldn t want to use our email program to watch video and v
13. about the fact that this 1s an evaluation version shows up click OK 12 Then a new window appears where we can see the simulation of the program 13 This window has several different supportive panels sub windows where we can monitor changes during the simulation The left hand side panel Registers provides information regarding the Registers of LPC17xx with which we are working 14 Again click on the Debug menu option and select Run The code starts simulating 15 It is good practice that before going ahead with the actual hardware implementation to perform a debug simulation session to make sure that our program behaves according to the design requirements 16 In our example we use PORTI 17 Go to Peripherals menu option then select GPIO Fast Interface followed by Port 1 18 You should get the window that shows P1 29 blinking 19 Stop the simulation Debug gt Stop or hit the Stop icon from the Toolbar Breakpoints l Let s set two breakpoints on lines LPC GPIO1 gt FIOPIN 1 lt lt 29 make P1 29 high LPC GPIO1 gt FIOPIN amp 1 lt lt 29 make P1 29 low inside blinkyl1 c To set a breakpoint right click on each of these lines on the left margin of the panel that displays this file and then select Insert Remove Breakpoint 2 Go to Peripherals menu option then select GPIO Fast Interface followed by Port 1 to show the GPIOI Fast Interface 24 3 Debug gt Run Notice that the simulation star
14. and 802 3 The IEEE 802 3 standard was part of a bigger 76 standard 802 This contains a number of different network technologies such as token ring and token bus as well as Ethernet These technologies are brought together by a layer on top of these MAC Layers called Logical Link Control LLC as shown in the figure below Ethernet IL however does not use this LLC layer LLC Logical Link Control MAC Media Access Control Physical Layer Figure 2 Illustration of LLC layer b Physical Layer The Physical Layer 1s concerned with the low level electronic way in which the signals are transmitted In Ethernet signals are transmitted using Manchester Phase Encoding MPE see Appendix A This encoding is used to ensure that clocking data is sent along with the data so that the sending and receiving device clocks are in sync The logic levels are transmitted along the medium using voltage levels of 0 85V The table below lists some of the cable types utilized by Ethernet networks The structure of a typical Ethernet cable is shown in the figure below 77 Pins 4 5 7 and amp are not used Fins 4 5 7 and amp are not used Pin number Wire Color Pin number Wire Color Pin 1 zz Orange White wire Becomes Pin 1 gt Orange White Pin 2 gt Orange 1 gt 4 Pin 2 gt Orange Pin 3 gt Green White Pin 3 gt Green White Pin 4 gt Blue 2 2 Pin 4 gt Blue Pin 5 gt Blu
15. bad if IP addresses were not so lengthy in size Which is easier to remember http 74 125 224 72 or google This handy service is accomplished on name servers which are just computers that store tables that translate domain names to and from IP addresses 90 Lab 7 Supplemental Material AR Drone Control 1 Objective The objective of this supplemental lab is to use the MCB1700 board a WRT54GL wireless router and a Wii NunChuck to control a Parrot AR Drone The overall set up of this project is shown in the figure below 192 168 1 1 acts as primary router amp Ca a m inh i uma E E 192 168 1 4 192 168 1 3 Figure 1 Overview of the project developed in this lab 2 AR Drone AR Drone is a sophisticated Linux based WiFi enabled flying embedded system It s a neat toy and much more The Parrot AR Drone was revealed at the International CES 2010 in Las Vegas At the same time Parrot also demonstrated the 1OS applications used to control it Along with AR Freeflight the application designed for free operation of the drone Parrot also released AR Race allowing users to participate 1n solo games or interact with other drones in combat simulations 91 z smi Bee oo1n iode RS ENS SNE 7 r f pa Pia Ga Tih EF OORT Se WI ji PEER EE 0008 0 a oosen FR Figure 2 AR Drone and its main board The AR drone can be piloted by an iPod app making it usable with any Wi
16. branches of the main if instruction Include this in your lab report 4 Modify Example 1 such that the characters typed on the host s keyboard are also displayed on the LCD display on the board Hint re use code from Blinky2 example of lab 1 5 Credits and references 1 LPC17xx user s manual http www nxp com documents user manual UM10360 pdf part of lab 1 files 2 NXP LPC17xx Datasheet http www nxp com documents data sheet LPC1769 68 67 66 65 _64 63 pdf part of lab 1 files 3 Schematic Diagram of the MCB1700 board http www keil com mcb1700 mcb1700 schematics pdf part of lab 2 files 4 MCB1700 Serial Ports http www keil com support man docs mcb1700 mcb1700 to serial htm 5 UART entry on Wikipedia click also on the references therein for RS 232 http en wikipedia org wiki Universal asynchronous receiver transmitter 6 Jonathan W Valvano Embedded Systems Introduction to Arm Cortex M3 Microcontrollers 2012 Chapters 8 9 Pong P Chu FPGA Prototyping by VHDL Examples Xilinx Spartan 3 Version Wiley 2008 Chapter 7 Lab manual of course http homes soic indiana edu geobrown c335 Chapter 5 EE 472 Course Note Pack Univ of Washington 2009 http abstract cs washington edu shwetak classes ee472 notes 472 note pack pdf Chapter 8 7 LPC1700 Code Bundle Download http ics nxp com support software code bundle lpc17xx keil 21 Documentation http ics nxp com liter
17. describe your results and any issues you may have faced during the assignment and how you solved them e Code listings assembly or C code that you wrote Appended at the end of your report Use smaller font size 9 to save space For full credit you must demo the correct operation of your assignment to the TA during the next lab While you are free to hand write your report still turned in as a PDF file please make sure your report is neat and the presentation is coherent You will lose points for reports that do not present enough details are ugly disorganized or are hard to follow read 5 Credits and references 1 Software Microcontroller Development Kit download from http www keil com arm mdk asp 6 2 Hardware MCB1700 board User s Guide http www keil com support man docs mcb1700 mcb1700 su connecting htm 3 LPC17xx user s manual http www nxp com documents user manual UM10360 pdf 4 NXP LPC17xx datasheet http www nxp com documents data_sheet LPC1769_68 67 66 65 64 63 pdf http www keil com dd chip 4868 htm 5 Cortex M3 information http www nxp com products microcontrollers cortex_m3 http www arm com products processors cortex m cortex m3 php 6 Additional resources Keil uVision User s Guide http www keil com support man docs uv4 Keil uVision4 IDE Getting Started Guide www keil com product brochures uv4 pdf ARM Assembler Guide http www keil com support man docs armasm
18. facilitate working with multiple slave devices simultaneously Most slave ICs utilize different pin names e g DI DO SCK and CS to the SPI interface For one way transfer devices such as DAC and single channel ADC either of data lines may be omitted The data bits are shifted in MSB first Master Slave MOSI Shift Register MISO Shift Register L wd S5 AD C DAC Comm MCU DSP etc Memory etc Figure 1 SPI communication method When additional slaves are attached to the SPI bus they are attached in parallel and an individual SS signal must be connected from the master to each of the slaves as shown in Fig 2 The data output of the slave IC 54 is enabled when the corresponding SS signal is set the data output 1s disconnected from the MISO line when the slave device 1s deselected Figure 2 Single master multiple slaves configuration In SPI data shift and data latch are done on opposite clock edges Consequently the four different operation modes as a result of the combination of clock polarity and clock phase that the master IC can configure its SPI interface are shown in Fig 3 below SPI Mode Timing Diagram Mode 0 Positive Pulse Latch then Shift CPHA 0 CPOL 0 Mode 1 Positive Pulse Shift then Latch Mode 2 Negative Pulse Latch then Shift Mode 3 Negative Pulse Shift then Latch Figure 3 The four different operation modes of SPI 55 There is
19. high level and assembly code In addition commands are available to manage breakpoints view RTOS Kernel information and invoke execution profiling You can modify the memory map and manage debugger functions and settings 23 Debug Toolbar Take a moment and read pages 67 68 of the uV IDE Getting Started Guide 1 The discussion on these pages present all the icons of the IDE related to the debugger Pre lab preparation Please take some time now and read fully Chapters 7 8 9 from the uV IDE Getting Started Guide 1 3 Example 1 Blinky 1 Revisited The files necessary for this example are located in examplel folder as part of the downloadable archive for this lab As mentioned earlier the u Vision Debugger can be configured as a Simulator or as a Target Debugger In this example we ll use the Simulator Go to the Debug tab of the Options for Target dialog to switch between the two debug modes and to configure each mode Configure to Use Simulator Before running the simulation replace the following two lines inside blinkyl c delay 1 24 with delay 1 14 This is to make the blinking of P1 29 faster inside the simulator otherwise we d need to wait too long to actually see the corresponding bit turning 1 or 0 Simulation Debug Open the Blinkyl project that you created in lab 1 or create a new project use files from examplel1 folder 11 Click Debug menu option and select Start Stop Debug Session A warning
20. host registers connect to the transmit and receive data path as well as the MAC e The DMA to AHB interface This provides an AHB master connection that allows the Ethernet block to access on chip SRAM for reading of descriptors writing of status and reading and writing data buffers e The Ethernet MAC which interfaces to the off chip PHY via an RMII interface e The transmit data path including The transmit DMA manager which reads descriptors and data from memory and writes status to memory The transmit retry module handling Ethernet retry and abort situations 83 The transmit flow control module which can insert Ethernet pause frames e The receive data path including The receive DMA manager which reads descriptors from memory and writes data and status to memory The Ethernet MAC which detects frame types by parsing part of the frame header The receive filter which can filter out certain Ethernet frames by applying different filtering schemes The receive buffer implementing a delay for receive frames to allow the filter to filter out certain frames before storing them to memory HOST REGISTERS register interface AHB slave TRANSMIT ETHERNET MAC RMII ADAP TER DMA interface AHB master RECEIVE BUFFER ETHERNET PHY RECEIVE FILTER ETHERNET BLOCK Figure 10 Block diagram of the Ethernet block of LPC17xx microcontrollers The fields of the Ethern
21. i GND l i ATO 5 OR CAN2 R2 3 GND 10k ENET_MDC CAN ETH MCB1750 only 100n GND Figure 1 Portion of the schematic diagram of MCB1700 board that shows the CAN1 2 connections 2 Please read through the pointers suggested 3 to learn more about CAN Also take a look at the datasheet of the NXP s TJA1040 High speed CAN transceiver integrated circuit included in the downloadable archive of this lab 4 33 3 Example 1 CAN2 CANI loopback on the same board The files necessary for this example are located in CAN Keil470 folder as part of the downloadable archive for this lab This is actually the whole uVision project directory Just copy it to keil_ examples this is the code bundle of lab 2 Then clean and re build the project Download to the board Connect the serial cable as shown in Fig 3 using the adaptor from your TA Observe operation and comment Figure 2 Block diagram of example 1 4 Example 2 CAN2 of board A sends to CANI of board B This 1s basically the same example as in the previous section You do not need to create another uVision project To do this example work with your neighboring team to realize the configuration shown in Fig 4 Use the serial cable to connect CAN2 of the transmitter board board A to the CANI of the receiver board board B Tune the potentiometer of board A and observe that it s received by board B which drives its 8 LEDs and also displays the data on the L
22. in buffer enable receiving data Note As mentioned in lab 1 in general one would not need to worry about these details about addresses to which registers are mapped It would be sufficient to just know of for example the definition and declaration of LPC UART TypeDef inside the header file LPCI7xx h To the C programmer it is transparent to what exact address the register IER is mapped to for example However now at the beginning it s instructive to track these things so that we get a better global picture of these concepts It also forces us to get better used with the LPC17xx User s Manual and the datasheets Notice that inside the source file uart c we have these two function descriptions Voso VARTO IROHdDOdler voud T VOTA UVARTE IRBOHandler volo d33x1 which are not called for example inside uarttest c but they appear inside startup LPC17xx s DGD UARTO IROHandler We HART DCD VARTL IBOHahndler s i272 HART The function void UARTO IROQHandler void is the UARTO interrupt handler Its name is UARTO_IRQHandler because it is named like that by the startup code inside the file startup LPC17xx s DCD is an assembler directive or pseudo op that defines a 32 bit constant To get a better idea about these things we need to make a parenthesis and discuss a bit about interrupts in the next section For the time being this discussion is enough We will discuss interrupts in more details in class lectures and in some of the next lab
23. is also the beginning of the next serial transfer the I2C bus will not be released S Slave Address R W 0 A Data A Data A A P 4 data transferred n bytes acknowledge Write Transaction S Slave Address R W 1 A Data A Data A P 4 data transferred n bytes acknowledge Read Transaction From master to slave A Acknowledge From slave to master A Not Acknowledge 8 Start condition P Stop Condition Figure 7 I2C write and read transactions 36 The LPC17xx I2C interfaces are byte oriented and have four operating modes master transmitter mode master receiver mode slave transmitter mode and slave receiver mode Please read Chapter 19 of the LPC17xx user manual for details on each of these operating modes 5 Also please read NXP I2C bus specification and user manual for even more details 6 I2C Device Addressing All I2C addresses are either 7 bits or 10 bits The use of 10 bit addresses is rare Most common chips use 7 bit addresses we can have up to 128 devices on the I2C bus When sending out the 7 bit address we still always send 8 bits The extra bit is used to inform the slave if the master is writing to 1t or reading from it If the bit is zero the master 1s writing to the slave If the bit is 1 the master 1s reading from the slave The 7 bit address 1s placed in the upper 7 bits of the byte and the Read Write R W bit 1s in the LSB 6 Wii NunChuck T
24. keil com rl arm kernel asp http infocenter arm com help index jsp topic com arm doc kui0062a rlarm_ar_ http www keil com support man docs rlarm rlarm_ar_svc_func htm 70 2 Robert Boys Keil RTX RTOS The Easy Way V0 4 2012 http www sase com ar 2012 files 2012 09 RLarmSteps pdf 3 Irene Huang ECE 254 Labs https ece uwaterloo ca yqhuang labs ece254 document html 4 On mutexes RL ARM Getting Started Chapter 2 http www keil com product brochures rl arm gs pdf Daniel Robbins Common threads POSIX threads explained The little things called mutexes http www ibm com developerworks library l posix2 A D Mashall Programming in C UNIX System Calls and Subroutines using C 2005 Chapter on Mutual Exclusion Locks http www cs cf ac uk Dave C node3 html SECTIONO03 1 10000000000000000 M Mitchell J Oldham and A Samuel Advanced linux programming 2001 Chapter 4 http advancedlinuxprogramming com alp folder alp ch04 threads pdf Multithreaded Programming POSIX pthreads Tutorial http randu org tutorials threads MSDN Introduction to Mutex Objects http msdn microsoft com en us library windows hardware ff548097 v vs 85 aspx Lock free programming http preshing com 20120612 an introduction to lock free programming APPENDIX A Listing of main_4tasks c of Example 1 project simple RL RTX application to blink an LED and to display 0 9 in a round robin fashion on L
25. know that a collision had occurred until after 2 propagation delays Collision Detection Knowing how long is needed to wait to discover if a collision has occurred we can use this to increase the effectiveness of CSMA CSMA behaves inefficiently when a collision occurs since both stations continue to send their full packet even though it will be corrupted A simple enhancement to CSMA is the addition of Collision Detection CSMA CD A simple check is made to make sure that the signal present on the medium is the same as the outgoing message If it isn t then a collision is occurring and the message can be aborted This means that the time spent sending the doomed messages can utilized for something else 75 Ethernet Protocol The Ethernet protocol is made up of a number of components a Ethernet frames b Physical Layer c MAC operation a Frame Structure Information is sent around an Ethernet network in discreet messages known as frames The frame structure consists of the following fields Preamble This consists of seven bytes all of the form 10101010 This allows the receiver s clock to be synchronized with the sender s Start Frame Delimiter This is a single byte 10101011 which is used to indicate the start of a frame Destination Address This is the address of the intended recipient of the frame The addresses 1n 802 3 use globally unique hardwired 48 bit addresses Source Address This is the add
26. of transmission was first used in a prototype packet radio network ALOHANET commissioned in Hawaii in 1970 and has been known ever since as unslotted ALOHA In Pure ALOHA packets contain some form of error detection which is verified by the receiver If the packet is received correctly the destination returns an acknowledgment If a collision occurs and the message is destroyed or corrupted then no acknowledgment will be sent If the sender does not receive an acknowledgment after a certain delay it will re send the message Carrier Sense Multiple Access CSMA The next stage in Collision Resolution after ALOHA was to add the ability for devices to detect whether the shared medium is idle or not This 1s called Carrier Sense Multiple Access or CSMA This however does not completely eliminate collisions since two devices could detect the medium as idle then attempt to send at approximately the same time CSMA is actually a family of protocols which vary by the method which they wait for the medium to become idle known as the persistence strategy Here is a list of two major strategies e 1 Persistent CSMA In this strategy when a device wants to send a message it first listens to the medium If it is idle the message is sent immediately however if it is busy the device continues to listen to the medium until it becomes idle and then sends the message immediately The problem 1s that if a number of devices attempt to send during a b
27. on the Source Group 1 and select Add files to Source Code Locate blinky1 c and include it to the group folder 9 Copy C Keil ARM Startup NXP LPC17xx system_LPC17xx c to labl directory and add it as a source file to the project too Open this file and browse it quickly to see what functions are defined dn inside it 10 Click Project menu and then select Build Target 11 Build Output panel should now show that the program 1s being compiled and linked This creates blinky1 axf file in ARM Executable Format which will be downloaded to the board To create a hex file more popular select Flash gt Configure Flash Tools gt Output and check mark Create HEX File 12 Connect the board to two USB ports of the host computer One connection is to the port J16 of the board the one that is a Standard B plug The second connection is via the ULINK2 debugger programmer emulator These connections are illustrated in Fig 1 13 Download the program to the Flash of the microcontroller Select Flash gt Download This loads the blinky1 axf file Then press the RESET push button of the board 14 Congratulations You just programmed your first project You should notice that the LED P1 29 is blinking If this 1s not the case then you should investigate debug your project to make it work ULINK2 P 1x a ufi Hit ee C Ge C4 Figure 1 Connection of ULINK2 to the board Debugging If your program has errors discovered by compiler
28. or linker or you simply want to debug it to verify its operation then we can use the debugging capabilities of the uVision tools 1 Click Debug menu option and select Start Stop Debug Session A warning about the fact that this is an evaluation version shows up click OK Then a new window appears where we can see the simulation of the program 3 This window has several different supportive panels sub windows where we can monitor changes during the simulation The left hand side panel Registers provides information regarding the Registers of LPC17xx with which we are working 4 Again click on the Debug menu option and select Run The code starts simulating 5 Itis good practice that before going ahead with the actual hardware implementation to perform a debug simulation session to make sure that our program behaves according to the design requirements 6 In our example we use PORTI 4 7 Go to Peripherals menu option then select GPIO Fast Interface followed by Port 1 8 You should get the window shown in Fig 2 below where you can see LED P1 29 blinking To actually observe this you should wait until the simulated time shown on the bottom right side of the uVision ISE window is longer than 1 second Note that in order to actually simulate 1 second of execution time of the program the simulator must run much longer This is expected as typically simulators require much longer computational runtimes wallclock time in order to
29. process We start with a chunk of application data to which we add a header We take that data application data plus application header and package it up as a series of TCP segments by adding TCP headers We then add an IP header to each TCP segment making IP datagram Finally we add Ethernet headers and trailers to the IP datagrams making an Ethernet frame that we can send over the wire Each layer has its own function TCP the transport layer makes sure data gets from point A to point B reliably and in order IP the network layer handles routing based on IP addresses and should be familiar to you and Ethernet the link layer adds low level MAC media access control addresses that specify actual physical devices It s also important to note that there are several choices at each layer of the model at the transport layer you can see either TCP UDP or ICMP Each layer of the network stack 1s unaware of the layers above and below The information coming from the layers above are simply treated as data to be encapsulated Many application protocols can be packed into TCP When the packet is received at its final destination the same process is repeated in reverse The packet is de encapsulated and the headers stripped off when it 1s received by the intended target 81 user data application application nnd E BEH t Y TOP header application data network S IP segiment TEP IP header TCP h
30. programs by writing the interrupt number to the NVIC gt STIR register values up to 111 are permitted We must clear interrupt conditions in the interrupt handler This is done in different ways depending on what caused the interrupt For example if we have INTO configured to generate an interrupt you would clear it by setting the low order bit of the LPC SC gt EXTINT register For detailed descriptions of all interrupts you should read Chapter 6 of the NXP LPC17xxx User Manual APPENDIX B Listing of source file blink1 lec09 c used in Example 3 of this lab this is a simple example which turns one of the MCB1700 board s LEDs on off it uses a Timer 0 interrupt we discussed it in lecture 9 in If class include LPC17xx h int main void 1 Timer 0 configuration see page 490 of user manual LPC SC gt PCONP 1 lt lt 1 Power up Timer 0 see page 63 of user manual LPC SC gt PCLKSELO 1 lt lt 2 Clock for timer CCLK i e CPU Clock page 56 user manual MRO is Match Register 0 MRO can be enabled through the MCR to reset the Timer Counter TC stop both the TC and PC and or generate an interrupt every time MRO matches the TC see page 492 and 496 of user manual LPC TIMO 2MRO 1 lt lt 23 Give a value suitable for the LED blinking 30 frequency based on the clock frequency MCR is Match Control Register The MCR is used to control if an interrupt i
31. studied later on in this lecture A block diagram of the SD card is shown in Fig 4 It consists of a 9 pin interface a card controller a memory interface and a memory core The 9 pin interface allows the exchange of data between a connected system and the card controller The controller can read write data from to the memory core using the memory core interface In addition several internal registers store the state of the card The controller responds to two types of user requests control and data Control requests set up the operation of the controller and allow access to the SD card registers Data requests are used to either read data from or write data to the memory core 56 TERT DAT2 DAT3 CMD CLE DATO DATI Interface Driver OCR 31 0 CID 127 0 RCA 15 0 Card Interface sisi at Controller CSD 127 0 SCE 63 0 Memory Core Interface Figure 4 Block diagram of an SD card B Communication with SD cards Communication with an SD card can be done in one of two modes the SD mode or the SPI mode By default the SD card operates in the SD mode However we ll work with the SPI mode and communicate with it using the SPI protocol Communication with the SD card is performed by sending commands to it and receiving responses from it A valid SD card command consists of 48 bits as shown in Fig 5 The leftmost two bits are the start bits which we set to 01 They are followed by a 6 bit command number and a 32
32. suited for small systems but has limitations for more complex applications These limitations include the following disadvantages e Time critical operations must be processed within interrupts ISR o ISR functions become complex and require long execution times o ISR nesting may create unpredictable execution time and stack requirements e Data exchange between Super Loop and ISR is via global shared variables o Application programmer must ensure data consistency e ASuper Loop can be easily synchronized with the System timer but o Ifa system requires several different cycle times it is hard to implement o Split of time consuming functions that exceed Super Loop cycle o Creates software overhead and application program is hard to understand e Super Loop applications become complex and therefore hard to extend o A simple change may have unpredictable side effects such side effects are time consuming to analyze These disadvantages of the Super Loop concept are solved by using a Real Time Operating System RTOS A RTOS separates the program functions into self contained tasks and implements an on demand scheduling of their execution An advanced RTOS such as the Keil RTX delivers many benefits including e Task scheduling tasks are called when needed ensuring better program flow and event response e Multitasking task scheduling gives the illusion of executing a number of tasks simultaneously e Deterministic behavior events and
33. these projects inside the keil examples directory with all the examples of the code bundle used in lab 2 so that you will not need to copy standard header files from common Build and download each of the projects Observe their operation You should observe a simplified in that circles are not filled operation of the one shown in Fig 2 below Read and compare the source code from main circles1 c and main circles2 c Which version do you think is better and why Is there anything that you would change to make this example more efficient AME 1111 s i us ous Figure 2 Plotting circles on the LCD display of MCB1700 board 27 7 Lab Assignment Write a program that uses the LCD screen of the MCB1700 board to display a smiley face in the center of the screen In your program you should use the Timer 0 Interrupt to trigger the change of color for the smiley face every other second The smiley face s color should alternate between yellow and red The size of the face should be approximately the size of a dime The background can be any other color different from yellow and red Hint Start with modifying any of the projects from Example 4 above This example has already functions for drawing empty circles and lines I have included already place holders for functions that you would need to describe write inside CRIS UTILS c and CRIS UTILS h Then you also need only to implement the logic of the main program by changing th
34. to detect motion acceleration but also as a tilt sensor when it is not in motion because we can use the earth s gravitational field as a reference Suppose we have measured values of gravity in three dimensions Gx Gy Gz Then Gi G G lg From this it is possible to compute pitch rotation around the X axis roll rotation around the Y axis and yaw rotation around the Z axis For joystick replacement it is sufficient to compute after range conversion to 512 511 pitch atan roll atan m Remember that this 1s for 360 degrees and a reasonable of motion to measure is perhaps 90 degrees Please read more about NunChuck hacking in the cited references 10 and on the Internet 7 Example 3 NunChuck data amp moving circle according to joystick displayed on LCD display of the MCB1700 board Note Because I have only one NunChuck and a single NunChuck adaptor and because this example requires some wiring you will not actually do this example in the lab I will demonstrate it in each of the lab sessions or in class However you should read and study the source code to get familiar with this example and how it uses I2C 39 In this example we use the I2C to connect the NunChuck to the board We ll display the data read from the NunChuck on the 320x240 pixels display and we ll use this data to move around a circle drawn on the display The files necessary for this example
35. 0 nal interrupt 1 not used on MCB1700 nal interrupt 2 not used on MCB1700 nal interrupt 3 not used on MCB1700 amp GPIO interrupt nd of conversion out detected not used not used on MCB1700 Det itive interrupt timer control PWM ature encoder hase locked loop DEIVITY DEIVICY 29 A particular peripheral can generate its interrupts for a variety of reasons which are configured within that peripheral For example timers can be configured to generate interrupts either on match or on capture The priorities of the interrupts can be set individually See sections 6 5 11 to 6 5 19 of the user manual for details A set of functions is available for enabling and disabling specific interrupts setting their priority and controlling their pending status find them inside core cm3 h file which is the so called CMSIS Cortex M3 Core Peripheral Access Layer Header File vold NVIC EnablelRO IROn Type IRON void NVIC DisablelRQ IBOn Type IRON void NHVIC SertPriorityi lROn Type IROD int34 t priority Gintas C NVI CetPriority IROn Type IRON void NVIC SetPendingIRBO IROn Type IRON void NVIC ClearPendinglBO lBROn Type IRO IRON Type NVIC GetPendingl RO TROn Type IROn The IRQn names are just the prefix from the table above with an n appended e g TIMEO IRQn We can also enable or disable interrupts altogether using disable irq and enable irq We can also trigger any interrupt in software inside our C
36. 0 address 5d 2 I2C connectors for I2C Bus 0 arrive here 3 DRAM cache 4 Connector to navigation board at least one serial port 92 5 USB driver SMSC USB3317 6 Connector to front camera probably not an I2C device 7 External connection port with TTYSO serial port and USB port 8 ROCm Atheros AR6102G BM2D wireless 9 Power supply for the engines 10 Ground 11 VCC 5V Read more details about AR Drone here Parrot AR Drone official website http ardrone2 parrot com usa AR Drone open API platform https projects ardrone org AR Drone Developer Guide SDK 1 7 http www ardrone flyers com wiki Version SDK 1 7 AR Drone mainboard overview Fig 1 right taken from here http awesome drone blogspot com Hacking the AR DRONE Parrot http www libcrack so 2012 10 13 hacking the ar drone parrot Chip Overclock s dissection 6 parts so far http coverclock blogspot com 201 1 02 deconstructing ardrone html http coverclock blogspot com 201 1 02 deconstructing ardrone part 2 html http coverclock blogspot com search label AR drone Shwetak N Patel Univ of Washington http abstract cs washington edu shwetak classes ee472 Buy it for about 300 at Amazon http www amazon com Parrot AR Drone Quadricopter Controlled Android dp BOO7HZLLOK ref sr_1_1 1e UTF8 amp qid 1367113226 amp sr 8 1 amp keywords ar drone 3 Linksys Wireless G WRTSAGL router This 1s already a somewhat old router but it s sti
37. 1 29 to drive one of the board s LEDs on and off the blinkyl example Refer to LPC17xx User s Manual Chapter 4 Clocking and Power Control Look for register Power Control for Peripherals register PCONP It s on page 63 bit 15 1s PGPIO Setting this bit to 1 should power up the GPIO ports Note that the default value is 1 anyway which means GPIO ports are powered up by default on reset but the start up code may modify this Hence it s good practice to make sure we take care of it For example here 1s how we power up the GPIO LPC SC PCONP 1 lt lt 15 Set desired clock to the peripheral In the same Chapter 4 of the manual look for Peripheral Clock Selection register PCLKSEL I it s on page 57 bits 3 2 set the clock divider for GPIO In our example since we re not using interrupts we won t change the default value Note that PCLK refers to Peripheral Clock and CCLK refers to CPU Clock PCLK is obtained by dividing CCLK see table 42 on page 57 of the manual Specify the pin operating mode Connect necessary pins using Pin Connect Block To specify the pin operating mode we configure PINSEL registers in the Pin Connect Block LPC PINCON macro defined in LPC17xx h There are eleven PINSEL registers PINSELO PINSELI PINSEL10 which are defined as member variables inside the LPC PINCON TypeDef C struct Each one of these eleven registers controls a specific set of pins on a certain port When the processor powers up o
38. 100 Hello World Figure 12 Webpage that shows the value of the ADC value of the MCB1700 board 8 Lab assignment This is optional If done correctly you may get up to 2 of the final grade Create a new uVision project and write a program that uses Ethernet to connect two boards and transmit the value of the ADC from one board to the other where it is displayed on the LCD screen 85 9 Credits and references 1 Ethernet Introduction Ross MCIlroy 2004 http www dcs gla ac uk ross Ethernet index htm Data Network Resource Rhys Haden 2013 http www rhyshaden com eth_intr htm OSI Model Wikipedia entry http en wikipedia org wiki OSI model Internet Protocol Wikipedia entry http en wikipedia org wiki TCP IP model How the Application Layer Works http learn networking com tcp ip how the application layer works ntroduction to Internet Architecture and Institutions Ethan Zuckerman and Andrew McLaughlin 2003 http cyber law harvard edu digitaldemocracy internetarchitecture html Internet The Big Picture http navigators com internet_architecture html Internet Technical Resources http www cs columbia edu hgs internet Internet Wikipedia entry http en wikipedia org wiki Internet 2 LPC17xx user manual 2010 http www nxp com documents user_manual UM10360 pdf APPENDIX A Manchester Phase Encoding MPE 802 3 Ethernet uses Manchester Phase Encoding MPE A data bit 1 from the l
39. 2 bit vector that points to the memory location where the ISR that handles the exception is located Vectors are stored in ROM at the beginning of the memory Here is an example of a few vectors as defined inside startup LPC17xx s _ EDLOPS DCD ANILA pp I Top DI Stack DCD heset Handler Reset Handler DCD AMIL Handler NMI Handler DCD Hardbault Handler Hard Fault Handler 19 External Interrupts DCO WDT IROHandler 16 Watchdog Timer DCD TIMERO IROHandler 17 TimerO DCD UARTO IRQHandler 21 UARTO ROM location 0x00000000 has the initial stack pointer and location 0x00000004 contains the initial program counter PC which is called the reset vector It points to a function called reset handler which 1s the first thing executed following reset Interrupts on the Cortex MG are controlled by the Nested Vector Interrupt Controller NVIC To activate an interrupt source we need to set its priority and enable that source in the NVIC i e activate set priority enable source in NVIC This activation is in addition to the arm and enable steps discussed earlier Table 50 in the User Manual page 73 lists the interrupt sources for each peripheral function Table 51 page 76 in User Manual summarizes the registers in the NVIC as implemented in the LPC17xx microcontroller Read the entire Chapter 6 of the User Manual pages 72 90 and identify the priority and enable registers and their fields of the NVIC Pay particu
40. 8 Table E 1 Pin functions for P2 10 Bits 21 20 of PINSELA Function Value after reset GPIO P2 10 pin default a EINTO 3 ma To write an interrupt handler in C we need to describe create a function with an appropriate name and it will automatically be used it will be called automatically via the pointers stored inside the vector table The name of this function consists of the prefix from the table below plus the keyword Handler appended e g TIMERO IRQHandler Description 0 WDT IRQ Watchdog timer i TIMERO IR Timer O0 2 TIMERI IRO Timer 1 3 TIMERZ IRQ Timer 2 4 TIMERS IRQ Timer 3 5 UARTO IRQ UART O0 6 UART1 IRQ UART 1 7 UART IRQ UART 2 8 UART3 IRQ UART 3 9 PWM1 IRQ PWM 1 not used on MCB1700 10 I2CO IRQ I2C 0 not used on MCB1700 id 120 IRO I2C 1 not used on MCB1700 12 T2CZ IRO I2C 2 not used on MCBI700 DE OPI IRO SPI used for communicating with LCD display 14 sePQ IRQ SSP O not used on MOBI O0D L5 S Pl IRU SSP 1 not used on MCB1700 16 PLLO IRO PLL O interrupts not used by our labs 17 RTOC IRO Real time clock 18 EINTO IRQ 19 EINT1 IRQ 20 EINT2 IRQ 21 EINT3 IRQ Pp ADC IRQ 73 BOD IRQ 24 USB IRQ 25 CAN IRQ 26 DMA IRQ 2T I28 TRO 28 ENET IRQ 29 RIT IRQ 30 MCPWM IRQ 31 QEI IRQ 32 PLL1 IRQ 23 U5BActivity IRQ 34 CANACtLIvaity IRQ EXLer BXrLer REGCLOT Exter ADC e Brown USB CAN DMA IS Ether Repet Motor Quadr USB P USB a CAN a nal interrupt O
41. A DE CC 0G 77 357 53 DS 33 8B 4G S CY 37 B1 OA 97 Pl w72803 74 QOOOOOOSO0 S 73 53 FS A3 ET VO 26 3F FC AF FF De B OF CD 885 c e usyoiol 0OOOOOCAO 8 61 D2 32 99 99 CC D2 42 99 4E 16 04 88 BC 2D aOzz mMI OBmN A OOOOoOBO DB DB ES B2 2C 6D AZ 1E BF FD 9C 11 73 22 10 i19 Dat me dels oooooocOo EE 56 8E 82 49 82 D4 Bi CF 9C 73 48 A6 E4 D BB iV2 1 Ot esd al 0O0OOCOODO 84 42 64 E6 BO AE AA 36 CD 39 E3 20 03 41 47 B5 Bde S 5198 icy QOOOOOOEO C5 DS AD 56 31 58 GE Fa ES AF SF B4 FO 75 DS 4C X18Z S aul Offset a Overwrite A Figure 11 Contents of png file displayed using HxD editor The program in this example found as the entire uVision project lab5 sd dbg inside the downloadable archive of lab 5 simply 1 initializes the SPI and the SD card and 2 reads data from the SD card starting at address 0x00040000 and then prints byte by byte to the putty terminal of the host PC This relatively simple set up is very useful for debugging purposes and for investigating micro SD cards which working with is kind of painful as a lot of times SD cards do not behave as theoretically described on sdcard org or for example in SanDisk s ambiguous documentation Use the provided uVision project lab8 sd dbg Clean and build then download to the MCB1700 board Observe operation and comment Study the source code The putty terminal should print useful information as in the figure below Note that the data r
42. Additional Mutex tokens cannot be created by tasks The main use of a Mutex is to control access to a chip resource such as a peripheral For this reason a Mutex token is binary and bounded Apart from this it really works in the same way as a semaphore First we must declare the Mutex container and initialize the Mutex OS Mut nct TOS LD mutex Then any task needing to access the peripheral must first acquire the Mutex token os mut wait OS ID mutex Ul16 timeout Finally when we are finished with the peripheral the Mutex must be released OS In t release 05 LD mutexr Mutex use is much more rigid than semaphore use but is a much safer mechanism when controlling absolute access to underlying chip registers 69 Take some time to read more on e Mutex management routines in RTX http www keil com support man docs rlarm rlarm ar mut mgmt funcs htm e Building Applications with RL ARM Getting Started included also in the lab files http www keil com product brochures rl arm_gs pdf b RTX Blinky Example This is the RTX Blinky example that comes bundled with the Keil uVision software installation You can find it in C Keil ARM Boards Keil MCB1700 RTX_Blinky or inside the downloadable archive with the files of this lab In this example four LEDs are blinking simulating the activation of the four output driver stages phase A B C D This is also displayed on the LCD display of the MCB1700 board Compile and download to the bo
43. CD Receiver Transmitter E TE zT w mr o saan 2 LI aT a T A E E Ng t ce his Figure 3 Block diagram of example 2 34 5 I2C Introduction I2C inter integrated circuit 1s a two wire protocol used to connect one or more masters with one or more slaves The case of a single master the LPC1768 communicating with two slave devices is illustrated in Fig 5 In this configuration a single master LPCxxxx communicates with two slaves over the pair of signal wires SCL serial clock line and SDA serial data address Example slave devices include temperature humidity and motion sensors as well as serial EEPROMs serial RAMs LCDs tone generators other microcontrollers etc OTHER DEVICE WITH OTHER DEVICE WITH I 2C INTERFACE 3C INTERFACE Figure 4 12C bus configuration Electrically the value of the two signal wires is high unless one of the connected devices pulls the signal low The two pull up resistors in Fig 5 force the default value of the two bus wires to VCC typically 3 3V Any device on the bus may safely force either wire low to GND at any time because the resistors limit the current draw however the communication protocol constrains when this should occur To communicate a master drives a clock signal on SCL while driving or allowing a slave to drive SDA Therefore the bit rate of a transfer is determined by the master The I2C Physical Proto
44. CD display of MCB1700 board this is meant to be a hello world example for RTX application development include lt stdio h gt include lt LPC17xx h gt include lt RTL h gt include GLCD h include LED h define FI 1 Use font index 16x24 global counters will count 60 seconds up and down int g Counter DU q Counters 00 char text bDufrerls displays 0 9 in a round robin fashion task void taskl void ine zx Us GLCD DisplayString QU dy Task 12 2 for esate d GLCD Displaychar 3y Ty ly A1v 0 93 os dlv waritil00 Notel The Delay function pauses the calling task by the amount of ticks passed as the argument Control will switch to the next task ready else passes to the idle demon After the specified number of ticks has expired the calling task will be placed in the ready state The delay does not use up 71 processing time with a loop if i 9 i 1 toggles LED 7 at P2 6 every second task void task2 void GLGD Displayocring 4 U 1 Task 27 bE for LED on 7 os dly wait 60 LED Grrl os dly wait 40 task that keeps incrementing a global counter task void Task void GLCD DisplayString 5 0 Jy Task 3 1 tor 77 1 d Counverlat if g counterl 60 g counterl 0 reset os diy we amp rxtilg0 Sprinti tex Durrer Sq g Counter GLCD DISPLAYS Agly Tp EFI WDE t Ltext DUFIer i
45. Fi enabled iDevice Android based apps have emerged too The drone has two video cameras one front facing and the other down facing plus an accelerometer two gyrometers and an ultrasonic altimeter It is all controlled by an ARM based processor running Linux Both the 10S based app and the Linux based embedded system are hackable Parrot provides an SDK and encourages developers to use it as an application platform Cool things can be developed with it imagine virtual reality I controlled my AR drone with 1 my iPod 2 laptop based application via the laptop s wireless card 3 same laptop based application via a Wireless G router WRT54GL which is connected to the laptop via an Ethernet cable the router is programmed to work as a wireless bridge also the laptop s own wireless card is shut off in this case and 4 MCB1700 board has an LPC1768 microcontroller connected to the WRT54GL router again set up as a wireless bridge and a Wii NunChuck In this supplemental lab we ll study the number 4 aforementioned scenario Some technical specifications of the AR Drone include of the first model e CPU 468MHz ARM embedded microcontroller e RAM 128MB e Interfaces USB and Wi Fi 802 11b g e Front camera VGA sensor with 93 lens e Vertical camera 64 lens recording up to 60fps A closer look at the motherboard 1s shown in Fig 1 which points out some of the main elements Camera I2C bus
46. ST3232C chip The ST3232C chip drives the two COMO and COMI represented by the two female DB9 connectors Note if you use an Embest LPC1700 board then note that these two connectors are male DB9 connectors To see these connections take a look on pages 1 and 3 of the schematic diagram of the board 3 included also in the downloadable files of this lab 2 For more details on UART and RS 232 please read references 1 6 In this lab we will explore serial communication between the target LPC1768 UART and a serial communication port of the host PC 3 EXAMPLE 1 Microcontroller echoes back the characters sent by host computer a Experiment In the first example of this lab we ll use an example project that comes with the LPC1700 code bundle The LPC1700 Code Bundle is a free software package from NXP that demonstrates the use of the built in peripherals on the NXP LPC17xx series of microcontrollers The example software includes a common library peripheral APIs and test modules for the APIs 14 Download LPC1700 Code Bundle from 7 http ics nxp com support software code bundle Ipc17xx keil and save it in your own work directory Save it with the plan to keep it as we ll revisit some other example in the future Unzip it to get the keil examples folder created with several examples therein Take a minute and read keil example readme txt now Launch Keil uVision4 and then open the project UART from among the exa
47. The State University of New York SUNY at Buffalo Department of Electrical Engineering Lab Manual v1 2013 EE 379 578 Embedded Systems and Applications Cristinel Ababei 192 168 1 1 acts as primary router wireless bridge 192 168 1 4 192 168 1 3 Copyleft by Cristinel Ababei 2013 Being a big supporter of open source this lab manual is free to use for educational purposes However you should credit the author The advanced materials are available for 1 which will be donated to my preferred charity Table of Contents Lab 1 A Blinky Introduction to C and Assembly ProgrammMing csccccssssecccessececeesecceeeesecessusecessenecetsenes 3 EDZ US i UART 13 Lab 3 Debugging and More on INterrupts ccccccsseccccesseccceeseccceeeccceeuseceeeesececeeneceeeeneecesseneceseueeceeseeeeeeeas 23 EA CAN I 32 Lab 5 USB audio Stepper MOELOF icisoec ate reko inrer sere oe Pis Erener AEEA RUPES SERES ENNEA lo Sex E Eas 47 Lab 5 Supplemental Material SPI and SD cards eeseeessseeeeeeeeneeene nennen nnns 54 Lab 6 Introduction to RTX Real Time Operating System RTOS ccsscccccessssecceeeeeeeceeeeeeeeeceeseeeeeeeeeeeas 66 Lab 7 Introduction to Ethernet sirsiran NE 74 Lab 7 Supplemental Material AR Drone Control ssssseessssesesseesesreresrrrsssreresererssreressreessrereserer
48. X There are several types of semaphores the basic idea behind each type is the same e Binary e Counting e Mutex Semaphores are typically used in one of two ways 1 To control access to a shared device between tasks A printer is a good example You don t want 2 tasks sending to the printer at once so you create a binary semaphore to control printer access When a device wishes to print it attempts to take the semaphore If the semaphore is available the task gets to print If the semaphore is not available the task will have to wait for the printer 2 Task synchronization By tasks taking and giving the same semaphore you can force them to perform operations in a desired order Counting semaphores are used when you might have multiple devices like 3 printers or multiple memory buffers Binary semaphores are used to gain exclusive access to a single resource like the serial port a non reentrant library routine or a hard disk drive A counting semaphore that has a maximum value of 1 is equivalent to a binary semaphore because the semaphore s value can only be 0 or 1 Mutex semaphores are optimized for use in controlling mutually exclusive access to a resource There are several implementations of this type of semaphore Mutex stands for Mutual Exclusion and is a specialized version of a semaphore Like a semaphore a Mutex is a container for tokens The difference is that a Mutex is initialized with one token
49. age The default value is 6 and normally is sufficient 4 Open up the Target Option window and activate the Target tab Choose RTX Kernel as the operating system default 1s set to None Click Use MicroLIB in the code generation window Options for Target rtx demo m eo Device Target Output Listing User C C Asm Linker Debug Utilities NXP founded by Philips LPC1758 Code Generation Keil IDE Target RTX Xtal MHz JAN Use Cross Module Optimization Use MicroLIB a 5 Now you can start to develop an RTX application Start with the os tsk function reference which is within the un Vision Help File Let s now create a simple example project called lab6 ex1 4tasks and place it in a new folder called lab6 ex1 4tasks The entire uVision project folder 1s included in the downloadable archive for this lab The main 4tasks c is also listed in Appendix A of this document This is a simple RTX application that lights up the first LED when it starts and then displays the Hello World string on the LCD screen Then the system creates an initialization task named init which spawns four tasks task1 task2 task3 and task4 task1 counts and displays digits 0 9 in a round robin fashion task2 makes a LED blinks every one second task3 keeps incrementing a global counter task4 keeps decrementing a global counter All these tasks are created with the same priority Tasks of equal priori
50. ally located in C Keil ARM INC NXP directory Step 3 Make sure the uVision4 Target setting is FLASH Then build the project by rebuilding all target files Download to the microcontroller and confirm that download 1s ok Step 4 Establish a Terminal connection Method 1 If your Windows is XP or older you can use HyperTerminal 15 Start HyperTerminal by clicking Start gt All Programs gt Accessories gt Communications gt HyperTerminal Connect HyperTerminal to the serial port that is connected to the COMO port of the evaluation board for example For the HyperTerminal settings you should use COMI double check that it the host s serial port is indeed COM 1in your case you can do that by Start gt Control Panel gt System gt Hardware gt Device Manager and click on Ports COM amp LPT if in your case it s a different port number then use that for example in my case as I use the USB to serial adapter with my laptop the port is COM14 baud rate 57600 8 data bits no parity 1 stop bit and no flow control Method 2 If your Windows is 7 or newer you first must make sure you download and or install a serial connection interface because HyperTerminal is not part of Windows 7 or later On the machines in the lab you can use Putty http www putty org Start gt All Programs gt Putty gt Putty Then select Connection Serial and type COMI or whatever is in your case find what it is as described
51. ample is located in example3 folder as part of the downloadable archive for this lab We discussed this example in class see lecture notes 9 First create a new uVision project and use the provided source file blink1 lec09 c Build and download Observe operation and comment Also take some time and read the file to remember anything that it does Target Debug 1 Configure the debugger to ULINK2 ME Cortex Debugger 2 Click Debug menu option and select Start Stop Debug Session 3 Open the Logic Analyzer by clicking the icon Analysis Windows gt Logic Analyzer 4 Click Setup in the new window of the logic analyzer Then click New Insert icon and type FIOIPIN Type in 0x20000000 as And Mask 5 Go to Peripherals menu option then select GPIO Fast Interface followed by Port 1 to show the GPIOI Fast Interface 6 Run simulation and step through the execution of the program Observe how the signal changes inside the Logic Analyzer window as well as inside the peripheral monitoring window Comment 6 Example 4 Drawing circles on the 320x240 pixels LCD display of the MCB1700 board You are given two versions of this example Version 1 files are located in lab3 circles1 and Version 2 files are located in lab3 circles2 Both versions do the same thing plot randomly sized circles at random locations and of random colors on the 320x240 LCD display of the board Create two different uVision projects for each version of this example Create
52. ard Observe operation and comment Take some time and read the source code from blinky c in order to get a good understanding of what s happening See how a mutex is utilized to control the access to the LCD display If you want to see how some ofthe os functions are implemented read the RTX source code from C Keil ARM RLARTX There is also an abundance of information on ARM s website For example here 1s the description of os mut wait http infocenter arm com help index sp topic com arm doc kui0062a rlarm os mut wait htm 6 Lab assignment This is optional and available only to undergraduates in this course If done correctly you may get up to 3 of the final grade Create a new uVision project and write a program using the Super Loop approach discussed in this lab to implement Example 2 You should not use RTX at all but your program should achieve the same behavior as RTX Blinky example Develop your program using only the programming techniques that we used earlier in this course This exercise is to outline the differences between RTX and Super Loop embedded programming approaches 7 Credits and references 0 Building Applications with RL ARM Getting Started included also in the lab files http www keil com product brochures rl arm_gs pdf 1 RTX Real Time Operating System http www keil com arm selector asp http www keil com rtos http www keil com rl arm rtx_rtosadv asp http www
53. ard by pressing keys on the keyboard These characters are sent back 1 e echoed looped back to the host computer by the MCU and are displayed in a hyperterminal window 2 UART The most basic method for communication with an embedded processor is asynchronous serial It 1s implemented over a symmetric pair of wires connecting two devices referred as host and target here though these terms are arbitrary Whenever the host has data to send to the target it does so by sending an encoded bit stream over its transmit TX wire This data 1s received by the target over its receive RX wire The communication is similar in the opposite direction This simple arrangement is illustrated in Fig 1 This mode of communications 1s called asynchronous because the host and target share no time reference no clock signal Instead temporal properties are encoded in the bit stream by the transmitter and must be decoded by the receiver RX TX Host Target TX RX Figure 1 Basic serial communication A commonly used device for encoding and decoding such asynchronous bit streams 1s a Universal Asynchronous Receiver Transmitter UART UART is a circuit that sends parallel data through a serial line UARTS are frequently used in conjunction with the RS 232 standard or specification which specifies the electrical mechanical functional and procedural characteristics of two data communication equipment A UART includes a transm
54. are located in I2C NunChuck folder as part of the downloadable archive for this lab This is actually the whole uVision project directory Just copy it to keil_ examples this is the code bundle of lab 2 Then clean and re build the project Download to the board Connect the NunChuck as shown as shown in Fig 13 using the wires provided by your instructor Observe operation and comment Figure 12 NunChuck connected to MCB1700 board Data from NunChuck controls the movement of a circle on the LCD display 8 Lab Assignment Pre lab report worth 6 points out of 20 points for this whole lab Write the pre lab report and explain line by line of code the following functions from inside can c file of example 1 void CAN setup u11n 52 OLEI 1 ess J void CAN Stare Wint32 Ctrl T wx 7 void CAN waitReady Uint32 Ctrl e J VOXd CAN wrMsSg Uints2 L OUrl CAN meg msg D 2 void CAN rdMsg Qurnt22 ccrl CAN meg msg 2 4 void CAN IROHandler void Lab assignment project demo worth 6 points final report worth 6 points 40 Modify example 1 as follows remove the part related to the ADC and add instead the part related to the UART from the example studied in lab 2 In fact from the UARTI source code you should add only the part that sends characters typed on the keyboard of the host PC to the board You can remove from the UART code the part that sends the characters back to the host PC which we used to di
55. ared inside the header file uart h as define IER THRE 0x02 define IER RLS 0x04 Which are utilized as masks in our instruction LPC UARTO gt IER IER THRE IER RLS Disable RBR So finally as we see the effect of this instruction is simply to turn 1 bit index 1 the second LSB out of 32 bits and bit index 2 the third LSB out of 32 bits of the IER register All other bits are set to 0 Having bit index 1 of this register set to 1 enables the Transmit Holding Register Empty THRE flag for UARTO see page 302 Table 275 of the LPC17xx User s Manual Having bit index 2 of this register set to 1 enables the UARTO RX line status interrupts see page 302 Table 275 of the LPC17xx User s Manual As already said all other bits are set therefore via this masking to 0 This includes the LSB 1 e bit index 0 out of 32 bits of IER register which is set to 0 The role of this bit as explained in the LPC17xx User s Manual on page 302 when set to 0 is to disable the Receive Data Available interrupt for UARTO You should be able now to explain what the following instruction does LPC UARTO gt IER IER THRE IER RLS IER RBR Re enable RBR summarizing what the code inside uarttest c does is as also mentioned in the previous section disable receiving data send back data to the PC from the buffer 1 e array variable UARTOBuffer reset counter of characters stored
56. ature presentations microcontrollers pdf code bundle lIpc 1 7xx keil uart pdf 8 Pluggable USB to RS 232 DB9 Serial Adapter Amazon http www amazon com Plugable Adapter Prolific PL2303H X Chipset dp B00425S1H8 ref sr_ 1 1 1e UTF8 amp qid 1359988639 amp sr 8 1 amp keywords plugablet usbt totserial Tigerdirect http www tigerdirect com applications SearchTools item details asp EdpNo 3753055 amp CatId 464 22 Lab 3 Debugging and More on Interrupts 1 Objective The objective of this lab is to learn about the different features of the debugger of uVision We ll do this by experimenting with several examples We ll also re emphasize some aspects about interrupts UART and Timer via these examples 2 uVision Debuger The Vision Debugger is completely integrated into the u Vision IDE It provides many features including the following 1 Disassembly of the code on C C source or assembly level with program execution in various stepping modes and various view modes like assembler text or mixed mode Multiple breakpoint options including access and complex breakpoints Review and modify memory variable and register values List the program call tree including stack variables Review the status of on chip microcontroller peripherals Debugging commands or C like scripting functions Code Coverage statistics for safety critical application testing Various analyzing tools to view statistics record values o
57. be read to identify which of eight possible interrupt sources are pending see page 492 and 493 of user manual if LPC TIMO gt IR amp 0x01 0x01 af MRO interrupt this 18 s sanity check LPC TIMO IR 1 lt lt 0 Clear MRO interrupt flag see page 492 and 493 of user manual LPC GPIOI gt FIOPIN I lt lt 29 Toggle the LED see 1abl 31 Lab 4 CAN and I2C 1 Objective The objective of this lab 1s to learn about Controller Area Network CAN We ll do this by experimenting with an example that on board A converts ADC the value of the potentiometer and sends it via CAN to board B where the LEDs will be turned on off by the received value The transmitted and received data are displayed on the LCD screens of both boards We ll also study I2C communication protocol and use a Wii NunChuck to control a moving circle on the LCD display 2 CAN Introduction This discussion is based on Chapter 16 of the LPC17xx user manual 1 Please take time to read the aforementioned chapter completely CAN Controllers Controller Area Network CAN is the definition of a high performance communication protocol for serial data communication The CAN Controller of the LPC1768 microcontroller supports 2 CAN controllers and buses 11 bit identifier as well as 29 bit identifier is designed to provide a full implementation of the CAN Protocol according to the CAN Specification Version 2 0B Microcontrollers with this
58. bit argument where additional information may be provided Next there are 7 bits containing a Cyclic Redundancy Check CRC code followed by a single stop bit 1 47 46 45 40 39 57 10 ommand Number Argument Figure 5 Format of the 48 bit command for an SD card 57 The CRC code is used by the SD card to verify the integrity of a command it receives By default the SD card ignores the CRC bits for most commands except CMD8 unless a user requests that CRC bits be checked upon receiving every message sending a command to the SD card is performed in serial fashion By default the MOSI line is set to 1 to indicate that no message is being sent The process of sending a message begins with placing its most significant bit on the MOSI line and then toggling the SD CLK signal from 0 to 1 and then back from 1 to 0 Then the second bit is placed on the MOSI line and again the SD CLK signal is toggled twice Repeating this procedure for each bit allows the SD card to receive a complete command Once the SD card receives a command it will begin processing it To respond to a command the SD card requires the SD CLK signal to toggle for at least 8 cycles Your program will have to toggle the SD CLK signal and maintain the MOSI line high while waiting for a response The length of a response message varies depending on the command Most of the commands get a response mostly in the form of 8 bit messages with two exceptions where the r
59. ces To arm disarm a device peripheral means to enable shut off the source of interrupts Each potential interrupting trigger has a separate arm bit One arms disarms a trigger if one is is not interested in interrupts from this source To enable disable means to allow interrupts at this time postponing interrupts until a later time On the ARM Coretx M3 processor there is one interrupt enable bit for the entire interrupt system In particular to disable interrupts we set the interrupt mask bit I in PRIMASK register Note An interrupt is one of five mechanisms to synchronize a microcontroller with an I O device The other mechanisms are blind cycle busy wait periodic polling and direct memory access With an input device the hardware will request an interrupt when input device has new data The software interrupt service will read from the input device and save in global RAM With an output device the hardware will request an interrupt when the output device is idle The software interrupt service will get data from a global structure and write it to the device Sometimes we configure the hardware timer to request interrupts on a periodic basis The software interrupt service will perform a special function for example a data acquisition system needs to read the ADC at a regular rate On the ARM Cortex M3 processor exceptions include resets software interrupts and hardware interrupts Each exception has an associated 3
60. col Communication between a master and a slave consists of a sequence of transactions where the master utilizes the SCL as a clock for serial data driven by the master or a slave on SDA as shown in Fig 6 When the master wishes to talk to a slave it begins by issuing a start sequence on the I2C bus A start sequence is one of two special sequences defined for the I2C bus the other being the stop sequence These are also referred to as Start condition S and Stop condition P SDA TALES XX XX C8 XCAK AIT SCL TINANA fr Ai ee ee ee 3 P Figure 5 I2C physical protocol 35 A transaction consists of a sequence of bytes Each byte 1s sent as a sequence of 8 bits The bits of each byte of data are placed on the SDA line starting with the MSB The SCL line is then pulsed high then low For every 8 bits transferred the device receiving the data sends back an acknowledge bit so there are actually 9 SCL clock pulses to transfer each 8 bit byte of data If the receiving device sends back a low ACK bit then it has received the data and is ready to accept another byte If it sends back a high Not Acknowledge NACK then it is indicating it cannot accept any further data and the master should terminate the transfer by sending a stop sequence sDA _ D7 D6 D5 D4 D3 D2 D1 DO ACK scL 1L 2L J3L Jal sl Je jv fa a Figure 6 Illustration of sending of 1 byte of data The data may be sent by either the slave or the master as the p
61. correction LPC1768 has a USB 2 0 interface that can be configured as e Host e Device e OTG USB On The Go often abbreviated USB OTG or just OTG is a specification that allows USB devices such as digital audio players or mobile phones to act as a host allowing other USB devices like a USB flash drive mouse or keyboard to be attached to them The USB device controller on the LPC17xx enables full speed 12 Mb s data exchange with a USB host controller A simplified block diagram of the three USB connectors of the MCB1700 board is shown in the figure below see also the schematic diagram of the MCB1700 board file available in archive of lab2 USB Micro AB ISP 1301 IC11 USB A right angle Figure 2 The three USB connectors on MCB1700 board Some of the most popular types of USB connectors are shown in figure below 48 B USB A Micro B Mini B LISB B Figure 3 Common USB connectors mme There is a lot of online information describing the USB As a start please read the first pointer from the references suggested in 2 Also take a look at Chapters 11 12 13 of the LPC17xx user manual 3 Example 1 Play audio to speaker of MCB1700 The Audio project example is a demo program for the KeilMCB1700 Board using the NXP LPC17xx Microcontroller It demonstrates an USB Audio Device Speaker The USB Audio Device is recognized by the host PC running Windows which will load a generic Audio driver and add a speake
62. could browse files on another computer just like they were located on the local computer Lastly we have file and print services If a computer needs to access a file server or a printer these services will allow the computer to do so While fairly self explanatory it s worth reviewing Network Utilities This 1s where most people have experience within the network utilities section of the Application Layer Every time you use a Ping Arp or Traceroute command you are taking full advantage of the Application Layer It s quite convenient that the Application Layer is located on the top of the TCP IP stack We can send a Ping and if successful can verify that the TCP IP stack is successfully functioning It s a good idea to commit each utility to memory as they are very useful for maintaining configuring and troubleshooting networks Listed below are seven of the most used utilities 1 ARP Arp stands for Address Resolution Protocol It is used to map an IP address to a physical address found on your NIC card Using this command can tell us what physical address belongs to which IP address 2 Netstat Netstat is a tool that displays local and remote connections to the computer It displays IP addresses ports protocol being used and the status of the connection 3 Ping Ping is a simple diagnostic tool that can check for connectivity between two points on a network It is one of the most used TCP IP utilities when setting up
63. cover like for example many of Altera s FPGA boards Objects can easily fall off and break the LCD display It happened with two boards in my lab In one instance an iPhone fell on the LCD display the display broke the iPhone was perfectly fine The board does not have simple header connectors like for example Arduino s stackable connectors for access to general purpose IOs Instead it has simple prototyping area directly on the board The price of 240 academic price without the ULINK2 programmer which is an additional 150 is high Please do not get me wrong MCB1700 is a beautiful board It has lots of nice peripheral devices and features However its construction makes it more appropriate for personal use when you would handle it gently and with care it s not designed for daily ab use in a teaching lab For the aforementioned reasons I will most like use the Land Tiger next time 99
64. d one way or the other Stepper motors are driven by digital pulses rather than by a continuous applied voltage Unlike conventional electric motors which rotate continuously stepper motors rotate or step in fixed angular increments A stepper motor is most commonly used for position control With a stepper motor driver controller system design it is assumed the stepper motor will follow digital instructions Most steppers can be stepped at audio frequencies allowing them to spin quite quickly and with an appropriate controller they may be started and stopped at controlled orientations 49 For some applications there is a choice between using servomotors and stepping motors Both types of motors offer similar opportunities for precise positioning but they differ in a number of ways Servomotors require analog feedback control systems of some type Typically this involves a potentiometer to provide feedback about the rotor position and some mix of circuitry to drive a current through the motor inversely proportional to the difference between the desired position and the current position In making a choice between steppers and servos a number of issues must be considered which of these will matter depends on the application For example the repeatability of positioning done with a stepping motor depends on the geometry of the motor rotor while the repeatability of positioning done with a servomotor generally depend
65. data it keeps the MISO line high Note that the response to each command is sent by the card a few SD CLK cycles later If the expected response is not received within 16 clock cycles after sending the reset command the reset command has to be sent again Following a successful reset test if your system can successfully communicate with the SD card by sending a different command For example send one of the following commands while keeping the CS at value 0 1 Command CMD8 01 001000 00000000 00000000 00000001 10101010 0000111 1 58 This command is only available in the latest cards compatible with SD card Specifications version 2 0 For most older cards this command should fail and cause the SD card to respond with a message that this command is illegal 11 Command CMD58 01 111010 00000000 00000000 00000000 00000000 0111010 1 This command requests the contents of the operating conditions register for the connected card A response to these commands consists of 40 bits see Fig 7 where the first 8 bits are identical to the basic 8 bit response while the remaining 32 bits contain specific information about the SD card Although the actual contents of the remaining 32 bits are not important for this discussion a valid response indicates that your command was transmitted and processed successfully If successful the first 8 bits of the response will be either 000000010r 00000101 depending on the version of your SD card 39 38 37 36 35
66. data_sheet BCANPSV2 pdf CAN Bus Description http www interfacebus com CAN Bus Description Vendors Canbus Protocol html Marco Di Natale Understanding and using the Controller Area Network 2008 http www inst eecs berkeley edu ee249 fa08 Lectures handout_canbus2 pdf CAN PPT presentation at CMU http www ece cmu edu ece649 lectures 11 can pdf 4 NXP s TJA1040 High speed CAN transceiver integrated circuit http www nxp com documents data_sheet TJA1040 pdf References of I2C 5 LPC17xx user manual Chapter 19 http www nxp com documents user manual UM10360 pdf 6 Pointers on I2C related information NXP I2C bus specification and user manual http www nxp com documents user manual UM10204 pdf tutorial 1 http www best microcontroller projects com 12c tutorial html tutotial 2 http www robot electronics co uk acatalog I2C_Tutorial html tutorial 3 http embedded lab com blog p 2583 Wikipedia entry http en wikipedia org wiki I e0C2 B2C 41 7 Lab manual of course http homes soic indiana edu geobrown c335 Chapter 9 8 http www 12c bus org addressing 9 I2C vs SPI http www byteparadigm com applications introduction to 12c and spi protocols 10 Pointers on NunChuck Robotshop http www robotshop com ca content PDF inex zx nunchuck datasheet pdf Chad Philips Read wii nunchuck data into arduino http www windmeadow com node 42 Wikipedia Wii remo
67. dem Line Home Business Figure 9 Illustration of the hierarchy of the Internet 6 Ethernet Block of LPC1768 The Ethernet block contains a full featured 10 Mbps or 100 Mbps Ethernet MAC Media Access Controller designed to provide optimized performance through the use of DMA hardware acceleration Features include a generous suite of control registers half or full duplex operation flow control control frames hardware acceleration for transmit retry receive packet filtering and wake up on LAN activity Automatic frame transmission and reception with Scatter Gather DMA off loads many operations from the CPU The Ethernet block is an AHB master that drives the AHB bus matrix Through the matrix it has access to all on chip RAM memories A recommended use of RAM by the Ethernet 1s to use one of the RAM blocks exclusively for Ethernet traffic That RAM would then be accessed only by the Ethernet and the CPU and possibly the GPDMA giving maximum bandwidth to the Ethernet function The Ethernet block interfaces between an off chip Ethernet PHY using the RMII Reduced Media Independent Interface protocol and the on chip MIIM Media Independent Interface Management serial bus also referred to as MDIO Management Data Input Output The block diagram of the Ethernet block shown in the figure below consists of e The host registers module containing the registers in the software view and handling AHB accesses to the Ethernet block The
68. diana edu geobrown c335 Application note http alumni cs ucr edu amitra sdcard Additional sdcard_appnote_foust pdf https www sdcard org home SDCARD Physical Layer Simplified Specification https www sdcard org downloads pls simplified specs archive partl 101 pdf Toshiba SD Card specification http embdev net attachment 39390 TOSHIBA SD Card Specification pdf MultiMediaCard MMC http en wikipedia org wiki MultiMediaCard Secure Digital SD Card http en wikipedia org wiki Secure Digital card FatFs Generic FAT File System Module http elm chan org fsw ff 00index e html 3 PNG and BMP formats http en wikipedia org wiki Portable Network Graphics http en wikipedia org wiki BMP file format 65 Lab 6 Introduction to RTX Real Time Operating System RTOS 1 Objective The objective of this lab is to learn how to write simple applications using RTX ARM Keil s real time operating system RTOS These simple examples involve flashing LEDs counting and displaying on the board s LCD display a simulation of how to drive a step motor In addition we ll look at FreeRTOS too Note A lot of the discussion in this lab is based on ARM s online information 2 RTOS simple embedded systems typically use a Super Loop concept where the application executes each function in a fixed order Interrupt Service Routines ISR are used for time critical program portions This approach is well
69. done by setting the bit 28 of registers FIO1CLR and FIO1SET Note one could do this in a simpler way by using a toggling trick toggle could be done using exclusive or with 1 bit 28 of register FIO1PIN instead page 122 of LPC17xx user manual and not use FIO1CLR and FIO1SET do not recommend however this trick as 11 loop led on led off due to the peculiarities of FIO1PIN SUBS RO 1 decrement RO this sets N Z V C status bits BNE led on if zero not reached yet go back and keep decrementing LDR R3 R2 recall that R2 stores FIO1CLR ORR R3 0x10000000 set to logic 1 bit 28 of R3 STR R3 R2 place R3 contents into FIO1CLR which will put pin on LOW LDR RO LEDDELAY initialize RO for countdown SUBS RO 1 decrement RO this sets N Z V C status bits BNE led off if zero not reached yet go back and keep decrementing LDR R3 R1 recall that R1 stores FIO1SET ORR R3 0x10000000 set to logic 1 bit 28 of R3 STR R3 R1 place R3 contents into FIO1SET which will put pin on HIGH LDR RO LEDDELAY initialize RO for countdown now do it again B loop ALIGN END 12 Lab 2 Using UART 1 Objective The objective of this lab is to utilize the Universal Asynchronous Receiver Transmitter UART to connect the MCB1700 board to the host computer Also we introduce the concept of interrupts briefly In the example project we send characters to the microcontroller unit MCU of the bo
70. e White Pin 5 gt Blue White Pin 6 gt Green 3 mam 3 Pin 6 gt Green Pin 7 gt Brown White Pin 7 gt Brown White Pin 8 gt Brown 6 mum 6 Pin 8 zz Brown Pins 4 5 7 and S are not used o EH Pins 4 5 7 and8 are not used Pin number Wire Color E Crossed Over Pin number Wire Color Pin 1 gt Orange White Pin 1 gt Green White Pin 2 gt Orange 1 mum 3 Pin 2 gt Green Pin 3 gt Green White Pin 3 gt Orange White Pin 4 gt Blue 2 Em 6 Pin 4 zz Blue Pin 5 gt Blue White Pin 5 gt Blue White Pin 6 zz Green 3 aa 1 Pin 6 zz Orange Pin 7 22 Brown White Pin 7 22 Brown White Pin 8 gt Brown 6 gt 2 Pin 8 gt Brown Figure 3 Ethernet cable structure c Media Access Control MAC Operation Ethernet is a CSMA CD Carrier Sense Multiple Access Collision Detection network To send a frame a station on an 802 3 network first listens to check if the medium is busy If it is then the station uses the 1 persistent strategy and transmits after only a short fixed delay the inter frame gap after the medium becomes idle If there is no collision then this message will be sent normally If the device detects a collision however the frame transmission stops and the station sends a jamming signal to alert other stations of the situation The station then decides how long to wait before re sending using a truncated binary exponential backoff algorithm The station
71. e main function The timer 0 interrupt is already set up in the Example 4 for you 8 Credits and references 1 Keil ARM Getting Started Creating Applications with u Vision http www keil com product brochures uv4 pdf included in lab 1 files too 2 uVision IDE and Debugger http www keil com uvision debug asp 3 Lab Manual for ECE455 https ece uwaterloo ca ece455 lab_manual pdf APPENDIX A More on Interrupts based in part on 3 The LPC1768 microprocessor can have many sources of interrupts All the internal peripherals are capable of generating interrupts The specific conditions that produce interrupts can be set individually for each peripheral The individual interrupts can be enabled or disabled using a set of registers think of memory locations in the memory space Selected GPIO pins can also be set to generate interrupts The push button INTO is connected to pin P2 10 of the LPC1768 microprocessor This pin can be a source of external interrupts to the MCU The table below shows different functionalities that can be assigned to P2 10 pin If you plan to use P2 10 as GPIO then you should also enable this source of interrupt as described in section 9 5 6 of the LPC17xx user manual Note that you can set the P2 10 pin to be sensitive to either the rising edge or the falling edge More information on clearing the interrupt pending bit can be found in table 123 1n section 9 5 6 1 page 139 of the user manual 2
72. e resolution to zoom in or out You can also scroll forward and backward in time using the scrollbar below the logic analyzer window There are also prev and next buttons to move quickly from one transition to another 1 Open the Logic Analyzer by clicking the icon Analysis Windows gt Logic Analyzer 2 Click Setup in the new window of the logic analyzer Then click New Insert icon and type FIOIPIN Type in 0x20000000 as And Mask 3 Go to Peripherals menu option then select GPIO Fast Interface followed by Port 1 to show the GPIOI Fast Interface 4 Runsimulation and observe how the signal changes inside the Logic Analyzer window 4 Example 2 UARTI sends Hello World Once Only The files necessary for this example are located in example2 folder as part of the downloadable archive for this lab This example is a modified simplified version of the example from lab 2 The simplified version uses only UARTI to simply send to the PC the string of characters Hello World Please take a moment and read the new files uart h uart c and uarttest c Observe the differences compared to the original example from lab 2 Discuss with your team member the functionality of this new example To work with this example go to your own folder where you have saved keil examples this is the code bundle of lab 2 and copy the whole directory UART to UART modified Then replace the files uart h uart c and uarttest c from
73. ead from the SD card matches the data shown using the HxD editor 63 MSD Init result 0 cardType 3D MsdBlockCount 1930240 MsdBlockSize 512 Byte MsdMemorySize 262 te MSD ReadBlo cki CMD17 acc MSD ReadBlock result data from SD Card result O da from SD Card result 1 from Sb Card result z from Sb Card result 3 from Sb Card result 4 from sD Care ult 5 from SD Card result 6 from SD Card result from Sb Card r ph 5 fram MEE t 9 from Sb Care uc 10 fram AREE ulti from sD Care ult le from Sb Card result 13 from Sb Card result 14 from Sb Card result 15 fram ae EAE oe from sD Care ult iF from Sb Card result i138 from Sb Card result 139 from Sb Card result Zz fram ee ult zi from sD Care ult z z2 from SD Card ult e3 Im apted co A re cn n m A i Im T F m IT m u rm to Im rU m WEN HH c mi H te Im T Im 1C nnn rn O oo m uy m m ul F Ei Ei Ei Ei Ei Ei Ei Ei Ei Ei Ei Ei Ei Ei Ei Ei Ei EI Ei Ei Ei Ei Ei Ei Im C A un ri m bor m T i n i n i n i Ti i T i T i T i n i n i T i T i ID iD D ID D ID D ID iD ID ID D ID D ID iD ID ID D ID D ID iD IT E d d i 7 d d ul 7 d d i 7 u d EORR OH HB oH oH oH oH o HoH Ho a HH Ti C Hh 5 Example 2 Read picture from micro SD card and display on the 320x240 LCD display of the MCB1700 board Thi
74. eader application data Mak i Erhemet i iP dir aigrarm 5 driver eader TCP header application data a susarubascues ronehesie rises 14 AX AX 4 ii Fhe frame E 45 t8 1506 bytes Figure 7 Illustration of encapsulation 5 The Internet The Internet is a global system of interconnected computer networks that use the standard Internet Protocol suite TCP IP to serve billions of users worldwide It is a network of networks that consists of millions of private public academic business and government networks of local to global scope that are linked by a broad array of electronic wireless and optical networking technologies The Internet carries an extensive range of information resources and services such as the inter linked hypertext documents of the World Wide Web WWW and the infrastructure to support email A simplified architecture of the Internet network is shown in the figure below b Internet Providers Corporate Network A ME a Telephone Campus Network Line Ethernet LAN B EA Figure 8 Simplified Internet architecture 82 Another view of the Internet that illustrates various components at different hierarchy levels is shown in figure below Conventional Phone Digital Subscriber or Cable Mo
75. eal Time Last 24 Hours Router IP Address 921681 2 Daily Subnet Mask 255 255 255 0 Weekly Monthly Default Gateway 192 1 58 1 1 Tools Static DNS 182 188 1 1 Port Basic 0 0 0 0 Network boo Identification TIE Wireless DONS static DHCP Enable Wireless v Wireless Filter MAC Address C8 D719 86 FD 69 Advanced Port Forwarding Wireless Mode Wireless Ethernet Bridge ans BiG Made Mixed Access Restriction SSD Briones 280860 Administration Channel 6 2437 GHz Scan About Reboot Security Disabled Figure 4 Setting up the router as wireless bridge Note For some reason each time I need to log in and set up the router I need to do the 30 30 30 hard reset described above which is becoming annoying An alternative to Tomato is DD WRT firmware http www dd wrt com site index I have not tried it yet though Read more details about WRT54GL wireless router and more here How To Turn An Old Router Into A Wireless Bridge http www makeuseof com tag how to turn an old router into a wireless bridge How To Extend Your Wi Fi Network With Simple Access Points http www howtogeek com 104469 how to extend your wi fi network with simple access points How To Extend Your Wireless Network with Tomato Powered Routers http www howtogeek com 104007 how to extend your wireless network with tomato powered routers Turn Your Old Router into a Range Boosting Wi Fi Repeater http lifehacker com 5563 196 turn
76. ely memory constrained e g 512K bytes flash which limits the ability to store large quantities of data either as inputs to or outputs from an embedded program For example in a game application it might be desirable to access sound and graphic files or in a data logging application to store extended amounts of data In addition accessing the contents of the flash requires a special interface and software In such applications it is desirable to provide external storage which the MCU can access while running and the user programmer can easily access at other times SD cards provide a cost effective solution which can be accessed by both the processor and user In practice these cards have file systems typically FAT and can be inserted in commonly available adaptors Furthermore the physical interface of most SD cards has a SPI mode described in the previous section and which is demonstrated with an actual implementation in Example 1 in the next section which 1s accessible Communicating with an SD memory card is relatively simple using some SPI driver like the one described in the previous section However controlling the card and interpreting the data communicated requires significant additional software Such software practically elevates the level of access to the card to a higher level of abstraction as illustrated in Fig 9 user or application space 60 FAT Driver SD Driver SPI Driver SPI Module SPI BUS Fig
77. esearch Center began the development of a bus topology LAN local area network In 1976 Xerox built a 2 94 Mbps network to connect over 100 personal workstations on a km cable This network was called the Ethernet named after the ether the single coaxial cable used to connect the machines Xerox Ethernet was so successful that in 1980 Digital Equipment Corporation Intel Corporation and Xerox had released a de facto standard for a 10 Mbps Ethernet informally called DIX Ethernet from the initials of the 3 companies This Ethernet Specification defined Ethernet II and was used as a basis for the IEEE 802 3 specification in 1985 Strictly Ethernet refers to a product which predates the IEEE 802 3 Standard However nowadays any 802 3 compliant network is referred to as an Ethernet Ethernet has largely replaced competing wired LAN technologies Over the years Ethernet has continued to evolve with 10Base5 using thick coaxial cable approved in 1986 10Base2 using cheaper thin coaxial cable approved in 1986 Twisted pair wiring was used in 10BaseT approved in 1991 and fiber optic in 1OBaseF approved in 1994 95 In 1995 100Mbps Ethernet was released increasing the speed of Ethernet which has since been further increased with the release of Gigabit Ethernet in 1998 99 In 2002 100 Gigabit was published and recently 100 Gigabit Ethernet or 100GbE and 40 Gigabit Ethernet or 40GbE emerged and were first defined by the IEEE 802 3ba 2010 standa
78. esponse consists of 40 bits To ensure the proper operation of the SD card the SD CLK signal should have a frequency in the range of 100 to 400 kHz To communicate with the SD card your program has to place the SD card into the SPI mode To do this set the MOSI and CS lines to logic value 1 and toggle SD CLK for at least 74 cycles After the 74 cycles or more have occurred your program should set the CS line to 0 and send the command CMD0 01 000000 00000000 00000000 00000000 00000000 1001010 1 This is the reset command which puts the SD card into the SPI mode if executed when the CS line is low The SD card will respond to the reset command by sending a basic 8 bit response on the MISO line The structure of this response is shown in Fig 6 The first bit 1s always a 0 while the other bits specify any errors that may have occured when processing the last message If the command you sent was successfully received then you will receive the message 00000001 76543210 DER in idle state erase reset illegal command CRC error erase sequence error address error parameter error Figure 6 Format of a basic 8 bit Response to every command in SPI mode To receive this message your program should continuously toggle the SD CLK signal and observe the MISO line for data while keeping the MOSI line high and the CS line low Your program can detect the message because every message begins with a 0 bit and when the SD card sends no
79. et packet are as shown in the figure below _ _ _ _ lt _ Lae LL packet PREAMBLE ETHERNET FRAME T bytes start of frame delimiter 1 byte a I des DESTINATION ADDRESS l DM I time Figure 11 Fields of the Ethernet packet 84 7 Example 1 EasyWEB This 1s the EasyWEB example that comes as part of the code bundle from NXP You can also find it inside the downloadable archive with the files of this lab The EMAC project is a simple embedded web server for the NXP LPC17xx microcontrollers also known as EasyWEB This tiny web server was taken from the Design amp Elektronik magazine extra issue Embedded Internet This software was adapted to work with a Keil MCB1700 board and the ARM RealView C Compiler with as few modifications as possible The served web page shows the value of one analog input AN2 which can be controlled via the blue potentiometer on the MCB1700 board Please read the 1 code bundle Ipc17xx keil emac pdf file included in the downloadable archive for this lab to see how to set up and run this example use the CAT 5E cable from your TA Compile and download to the board Observe operation and comment When up and running you should see the webpage shown in the figure below Take some time and read the source code in order to get a good understanding of what s happening 5 easy WEB dynamic webside X gt C ff 192 168 0
80. evel encoded signal 1 e that from the digital circuitry in the host machine sending data is represented by a full cycle of the inverted signal from the master clock which matches with the 0 to 1 rise of the phase encoded signal linked to the phase of the carrier signal which goes out on the wire 1 e V in the first half of the signal and V in the second half The data bit 0 from the level encoded signal is represented by a full normal cycle of the master clock which gives the 1 to 0 fall of the phase encoded signal 1 e V in the first half of the signal and V in the second half The following diagram shows graphically how MPE operates The example at the bottom of the diagram indicates how the digital bit stream 10110 is encoded a 1 bit D bit A Figure 13 Illustration of MPE operation 86 A transition in the middle of each bit makes it possible to synchronize the sender and receiver At any instant the ether can be in one of three states transmitting a 0 bit 0 85v transmitting a bit 0 85v or idle 0 volts Having a normal clock signal as well as an inverted clock signal leads to regular transitions which means that synchronization of clocks is easily achieved even if there are a series of 0 s or I s This results in highly reliable data transmission The master clock speed for Manchester encoding always matches the data speed and this determines the carrier signal frequency so for 10Mb
81. f variables and peripheral I O signals and to display them on a time axis nstruction Trace capabilities to view the history of executed instructions The pu Vision Debugger offers two operating modes 1 Simulator Mode configures the u Vision Debugger as a software only product that accurately simulates target systems including instructions and most on chip peripherals serial port external I O timers and interrupts peripheral simulation capabilities vary depending on the device you have selected In this mode you can test your application code before any hardware is available It gives you serious benefits for rapid development of reliable embedded software 2 Target Mode connects the nu Vision Debugger to real hardware Several target drivers are available that interface to a ULINK JTAG OCDS Adapter that connects to on chip debugging systems Monitor that may be integrated with user hardware or that 1s available on many evaluation boards Emulator that connects to the microcontroller pins of the target hardware In System Debugger that is part of the user application program and provides basic test functions ULINKPro Adapter a high speed debug and trace unit connecting to on chip debugging systems via JTAG SWD SWYV and offering Cortex M3ETM Instruction Trace capabilities Debug Menu The Debug Menu of uVision IDE includes commands that start and stop a debug session reset the CPU run and halt the program and single step in
82. figure your router to act as the client With the wrt54gl routers one can use Tomato s firmware http www polarcloud com tomato Tomato is a simple replacement firmware for Linksys WRT54G GL GS Buffalo WHR G54S WHR HP G54 and other Broadcom based routers It features an easy to use GUI a new bandwidth usage monitor more advanced QOS and access restrictions enables new wireless features such as WDS and wireless client modes raises the limits on maximum connections for P2P allows you to run your custom scripts or telnet ssh in and do all sorts of things like re program the SES AOSS button adds wireless site survey to see your wifi neighbors and more So download the Tomato s firmware and save it on your computer you will need only WRT54G WRTSAGL bin Then open the original Linksys GUI in your browser The default URL 1s http 192 168 1 1 Leave user name as blank and type admin as password Select Upgrade Firmware and use Tomato s WRT54G WRTSAGL bin After a few minutes the upgrade will be done Next we do a so called Hard Reset a k a 30 30 30 reset of the router The following procedure will clear out the NVRAM and set dd wrt back to default values e With the unit powered on press and hold the reset button on back of unit for 30 seconds e Without releasing the reset button unplug the unit and hold reset for another 30 seconds e Plug the unit back while STILL holding the reset button a final 30 seconds Note This
83. he Wii NunChuk is an input device with a joystick two buttons and a three axis accelerometer as illustrated in Fig 9 10 The three axes X Y and Z correspond to the data produced by the accelerometer Joystick X is right left Y is forward backwards and Z 1s up down accelerometer only C button 3 3V y AU E SDA N C 4 aN M Analog joystick Z button Ni i 4 7 L sensor is installed in 1 right angle axis with joystick m GND sa 7 Handheld Pin assignment of Nunchuk connector M See from front view i Hi i 3 axis acceleromoter j 2 Nunchuk component Figure 8 NunChuck basic information Y g Z C button a gt a Z button X x Fa M g x a d x Ae J Analog joystick X j bw p Fi Los Figure 9 NunChuck X Y Z The NunChuck communicate via I2C We ll hook the NunChuck to the I2C1 bus of the LPC1768 microcontroller on the MCB1700 board We ll initialize the Nunchuk to a known state and then to regularly poll its state The data are read from the NunChuck in a six byte read transaction These data are 37 formatted as illustrated in Fig 11 and are read beginning with byte 0x0 little endian The only complication with this format 1s that the 10 bit axis accelerometer data are split Joystick JX Joystick JY Accelerometer A X 8 2 Accelerometer AY 9 2 Accelerometer A Z 8 2 AX LO Figure 10 Forma
84. ication was used to connect devices such as printers cameras scanners etc to a desktop computer but it has largely been replaced by USB SPI is still utilized as a communication means for some applications using displays memory cards sensors etc SPI runs using a master slave set up and can run in full duplex mode 1 e signals can be transmitted between the master and the slave simultaneously When multiple slaves are present SPI requires no addressing to differentiate between these slaves There is no standard communication protocol for SPI SPI is used to control peripheral devices and has some advantages over I2C Because of its simplicity and generality it is being incorporated in various peripheral ICs The number of signals of SPI three or four wires is larger than I2C s two wires but the transfer rate can rise up to 20 Mbps or higher depends on device s ability 5 50 times faster than I2C Therefore often it is used in applications ADC DAC or communication between ICs that require high data transfer rates The SPI communication method is illustrated in Fig 1 below The master IC and the slave IC are tied with three signal lines SCLK Serial Clock MISO Master In Slave Out and MOSI Master Out Slave In The contents of both 8 bit shift registers are exchanged with the shift clock driven by master IC An additional fourth signal SS Slave Select is utilized to synchronize the start of packet or byte boundary and to
85. ice versa This problem is addressed by using channels called ports These numbered ports each correspond to a certain action For example the email 1s likely using port 25 for operation Files you upload to your website use the FTP port which is usually port 20 and 21 Browsing a webpage uses a specific port the HTTP port 80 In total there are 65 535 ports for controlling the flow of information b Error and Flow Control TCP IP is considered a connection oriented protocol suite This means that if data isn t received correctly a request to resend the data is made This is compared to User Datagram Protocol UDP which 1s connectionless UDP is a suite of protocols just like TCP IP with a few notable differences UDP is great for broadcasting data such as streaming radio music If part of the data was lost we wouldn t want to go back and retrieve it it would waste bandwidth and would create collisions or noise in our signal With UDP the lost data might be represented as a silent spot c Logical Addressing Most computers today come standard with Network Interface Cards NICs These cards are the actual hardware used to communicate to other computers Each card has a unique physical address that is set at the factory and can t be changed Essentially this is an identifier for the computer it is installed on Networks rely on the physical address of a computer for data delivery but we have a problem The NIC card is co
86. in Method 1 baud rate 57600 8 data bits no parity I stop bit and no flow control Click on Session and choose the type of connection as Serial Save the session for example as lab2 Finally click on Open you should get HyperTerminal like window Method 3 You can use other programs such as TeraTerm http logmett com index php products teraterm html or HyperSerialPort http www hyperserialport com index html or RealTerm http realterm sourceforge net or CoolTerm http freeware the meiers org etc Step 5 Type some text It should appear in the HyperTerminal window This is the result of First what you type is sent to the microcontroller via the serial port that uses a UART Second the MCU receives that via its own UART and echoes sends back the typed characters using the same UART The host PC receives the echoed characters that are displayed in the HyperTerminal Disconnect the serial cable from COMO and connect it to COMI port on the MCB1700 board The behavior of project should be the same Step 6 optional do not do it on computers in the lab On your own computer only download and install NXP s FlashMagic tool from here http www flashmagictool com Then follow the steps that describe how to use this tool as presented in the last part of the UART documentation for the code bundle http ics nxp com literature presentations microcontrollers pdf code bundle lpc 1 7xx keil uart pdf included
87. interrupts are handled within a defined time e Shorter ISRs enables more deterministic interrupt behavior e Inter task communication manages the sharing of data memory and hardware resources among multiple tasks e Defined stack usage each task is allocated a defined stack space enabling predictable memory usage e System management allows you to focus on application development rather than resource management housekeeping 66 3 RL RTX The Keil RTX Real Time eXecutive is a royalty free deterministic RTOS designed for ARM and Cortex M devices It 1s one of the components of RL ARM the RealView Real Time Library RL ARM RTX and its source code are available in all MDK ARM Editions 1 RTX allows one to create programs that simultaneously perform multiple functions or tasks statically created processes and helps to create applications which are better structured and more easily maintained Tasks can be assigned execution priorities The RTX kernel uses the execution priorities to select the next task to run preemptive scheduling It provides additional functions for inter task communication memory management and peripheral management RTOS and Middleware Components RTX RTOS Source Code TCPnet Networking Suite Flash File System USB Device Interface Examples and Templates CAN Interface Figure 1 RL ARM Real Time Library and RTX Real Time Operating System diagrams The main features of RTX incl
88. istinel Ababei SUNY at Buffalo 2012 this is one assembly implementation of the infamous blinky example 9 target microcontroler LPC 1768 available on board Keil MCB1700 or Embest EM LPC1700 board tested it first on EM LPC1700 board as it s cheaper Note1 it has lots of comments as it is intended for the one who sees for the first time assembly Note2 some parts of the implementation are written in a more complicated manner than necessary for the purpose of illustrating for example different memory addressing methods Note3 each project will have to have added to it also system LPC17xx s added automatically by Keil uVision when you create your project and system LPC17xx c Which you can copy from your install directory of Keil IDE for example C Keil ARM Startup NXP LPC17xx system_LPC17xx c Note4 system LPC17xx s basically should contain the following elements defines the size of the stack defines the size of the heap defines the reset vector and all interrupt vectors the reset handler that jumps to your code default interrupt service routines that do nothing defines some functions for enabling and disabling interrupts Directives they assist and control the assembly process directives or pseudo ops are not part of the instruction set they change the way the code is assembled THUMB directive placed at the top of the file to specify that code i
89. itter and a receiver The transmitter 1s essentially a special shift register that loads data in parallel and then shifts it out bit by bit at a specific rate The receiver on the other hand shifts in data bit by bit and reassembles the data The serial line is 1 when it is idle The transmission starts with a start bit which is 0 followed by data bits and an optional parity bit and ends with stop bits which are 1 The number of data bits can be 6 7 or 8 The optional parity bit is used for error detection For odd parity it is set to 0 when the data bits have an odd number of 1 s For even parity it is set to 0 when the data bits have an even number of 1 s The number of stop bits can be 1 1 5 or 2 The transmission with 8 data bits no parity and 1 stop bit is shown in Fig 2 note that the LSB of the data word is transmitted first idle Kc start bit stop bit Figure 2 Transmission of a byte 13 No clock information is conveyed through the serial line Before the transmission starts the transmitter and receiver must agree on a set of parameters in advance which include the baud rate 1 e number of bits per second the number of data bits and stop bits and use of parity bit To understand how the UART s receiver extracts encoded data assume it has a clock running at a multiple of the baud rate e g 16x Starting in the idle state as shown in Fig 3 the receiver sam
90. joystick as input we write the following C code LPC GPIO1 FIODIR amp 1 lt lt 20 1 lt lt 23 1 24 1 lt lt 25 1 26 P1 20 P1 23 P1 26 are input Joystick In our blinky example we set all pins connected to the 8 LEDs as output We achieve that via the following C code LPC _GPIO1 gt FIODIR 0xB0000000 pins P1 28 P1 29 P1 31 as output LPC GPIO2 FIODIR 0x0000007C pins P2 2 3 4 5 6 as output Once a pin is set as output or input it can be utilized in our programs to drive or read logic values a The pin is set as output We turn a pin to HIGH LOW i1 e digital logic 1 0 by setting the corresponding bit in FIOSET FIOCLR register Both FIOSET and FIOCLR are member variables defined in the PC GPIO TypeDef C struct To set a pin to digital 1 set the corresponding bit of LPC_GPIOx gt FIOSET to 1 To turn a pin to digital 0 set the corresponding bit of LPC_GPIOx gt FIOCLR to 1 Refer to Sections 9 5 2 and 9 5 3 of LPC17xx User s manual for details For example to turn on LED P1 29 the following code can be used LPC _GPIO1 gt FIOSET 1 lt lt 29 In general to turn any of the 8 LEDs on one can use the following trick const U8 led pos 8 28 29 31 2 3 4 5 6 mask 1 lt lt led pos led if led lt 3 P1 28 29 31 are part of Portl LPC _GPIO1 gt FIOSET mask else P2 2 3 4 5 6 are part of Port2 LPC _GPIO2 gt FIOSET mask
91. lar attention to 1 e search watch for UARTO in this Chapter How would you set the priority and enable UARTO as a source of interrupts Coming back to our discussion of the function void UARTO IROQHandler void in uart c we see a first instruction IIRValue LPC UARTO IIR What does it do It simply reads the value of LPC UARTO IIR and assigns it to a variable whose name is IIRValue LPC UARTO IIR is the value of the register IIR Interrupt Dentification Register identifies which interrupt s are pending which is one of several 14 of them registers associated with the UARTO peripheral device You can see it as well as the other registers on page 300 of the User Manual Take a while and read them all The fields of the interrupt register IIR are later described on page 303 in the User Manual Take another while and read them all on pages 303 304 Next inside uart c we see IIRValue gt gt 1 skip pending bit in IIR IIRValue amp 0x07 check bit 1 3 interrupt identification 7 Which shifts right with one bit IIRValue and then AND s it with 0x07 This effectively zooms in onto the field formed by bits index 1 3 from the original LPC_UARTO gt IIR bits which are now in the position bits index 0 2 of IIRValue variable Going on we find an if instruction with several branches if IIRValue IIR RLS Receive Line Status lues else if IIRValue IIR RDA Receive Data Available
92. ld produce about a second when del 1 24 or so of delay depending on CCLK volatile uinto2 t temp void delay dirty uint os E del 42 di fi 4 Ti r7 7 i zy if if i Li Uints2 t Xj for i20 i del i temp i Communication with the Nunchuk consists of two phases phase 1 initialization phase executed once in which specific data are written to the Nunchuk Essentially initialization consists of two write transactions each of which writes a single byte to a register internal to the I2C slave reg Oxf0 0x55 reg Oxfb 0x00 phase 2 repeated read phase in which six data bytes are read again and again each read phase consists of two transactions a write transaction which sets the read address to zero and a read transaction NOTES 3 I2CO0 only supports fast mode that the NunChuck uses When I2CO is used the pin connections are SDA P0 27 SCL P0 28 When I2C1 is used the pin connections are SDA P0 19 SCL P0 20 void Nunchuck phasel init void this function should be called once only Mints t ag I2CWriteLength PORT USED 3 write 3 bytes I2CReadLength PORT USED 0 read 0 bytes iZCMastereurter PORT USED 0 NUNCHUK ADDRESS SLAVEI i12CMasterBurfer PORT USED I OxF0 at adress OxFO of NunChuck write I2CMasterBuffer PORT USED 2 0x55s data 0x55 I2CEngzine PORT USED 3j should I introduce a delay people say it s
93. ll very popular and with a lot of online support It can be utilized as an access point to extend your wireless LAN but also as a wireless bridge to further extend your network A nice thing is that it can be utilized as a wireless card for a laptop PC which does not have one not to mention its Linux compatibility The Linksys Wireless G Broadband Router is really three devices in one box First there s the Wireless Access Point which lets you connect both screaming fast Wireless G 802 11g at 54Mbps and Wireless B 802 11b at 11Mbps devices to the network There s also a built in 4 port full duplex 10 100 Switch to connect your wired Ethernet devices together Connect four PCs directly or attach more hubs and switches to create as big a network as you need Finally the Router function ties it all together and lets your whole network share a high speed cable or DSL Internet connection Figure 3 Wireless G WRT54GL router 93 We ll this router to connect to and control the AR Drone To do that we need to set it to work as a wireless bridge But before that we must update its firmware with Tomato The drone itself acts as a router that s why it can t connect to another router like a wrt54gl With factory software 1s can t function as a client of another router but routers can be reconfigured to relay the drones signal and extend the range The drone emits a standard wifi signal for clients to connect to so you have to con
94. lt 2 7 Z b tton 0 Cc button Uy byte I2CSlaveBuffer PORT USED 5 contains bits for z and c buttons it also contains the least significant bits for the accelerometer data if byte5 gt gt 0 amp 1 z Dutton 1 if byte5 gt gt 1 amp 1 45 c button 1j accel x axis bytes 2 amp 0x05 accel y axis bytes gt gt 4 amp DxODS accel z axis 49 bytes gt gt O amp DxOUS void NunChuck print data init void this should be called once only GLCD SetTektColor White GLCD Clear Black clear graphical LCD display set all pixels to Black GLCD SetBackColor Black set background color for when characters text is printed GLCD SetTextColor White GLCD Displayotring 0 D FI This is I2C example GLCD DisplayString l 0 FI Data from NunChuck GLCD DiBSplaysStraing 2 2 FT Joya GLCD Dasplavstring 2 2 _ FI oyr GLCD DasplayBtraingii 2 TI TWO eU GLCD DisplaysBtringi o Z Il acer 33 GLCD Display tting b Z2 PI aces GLCD Dasplavstringi Z FI A id 2 GLCD DaisplaysStraingi3 2 PI C ew s void NunChuck print data void this is called as many times as reads from the NunChuck GLCD S etTexccolor White 7 sprinti text butter 050 Joy x axis GLCD Displays5trangi2 20 EI pinto t texL butter 7 Sprintrf text burfer 050 Joy y axis GLCD Displaystrangi 2 10 FI aimee t text buffer Sprint
95. mple just downloaded The UART project is a simple program for the NXP LPC17xx microcontrollers using Keil s MCB1700 evaluation board When sending some characters from a terminal program on the PC at a speed of 57600 Baud to the LPC17xx UARTO or UARTI the LPC17xx will echo those same characters back to the terminal program Step 1 Connect the board ULINK2 and the host computer as shown in Fig 4 Ask the TA for the COMO I to Serial Port cable Note Remove the RST and ISP jumpers on the MCB1700 board USB i Cable 1 USB Ports F Serial Port USB Cable 2 Note instead of ULINK2 you can also use ULINK ME Remove the RST and ISP jumpers Please keep the jumpers safe and place them back when you are done with this lab Note If you are doing this lab using a laptop which does not have a serial port you can use a USB Serial Converter I got mine for about 12 from Amazon S8 and it works great Step 2 Familiarize yourself with the following files uart c contains the UARTO UARTI handlers driver functions uarttest c contains a small test program utilizing the UART driver system_LPC17xx c Cortex M3 Device Peripheral Access Layer Source File startup LPC17xx s CMSIS Cortex M3 Core Device Startup File Abstract txt Describes what the uarttest c program does Change include Ipc17xx h to include lt lpc17xx h gt This is done in order to use the latest Keil s release of the header file norm
96. n 0x20090000 to R1 MOVT assigns to upper nibble MOV R3 0xC000 move 0xCO000 into R3 ADD R1 R1 R3 add 0xC000 to R1 to get 0x2009C000 MOV R4 0xB0000000 place 0xB0000000 i e bits 28 29 31 into R4 now place contents of R4 i e 0OxXB0000000 to address 0x2009C020 i e register FIO1DIR this sets pins 28 29 31 as output direction Note address is created by adding the offset 0x20 to R1 Note the entire complication above could be replaced with simply loading R1 with FIO1DIR but we wanted to experiment with different flavors of MOV to upper and lower nibbles we ll use the simpler version later STR R4 R1 20x20 MOV R4 0x0000007C value to go to register of Port 2 STR R4 R1 40x40 set output direction for pins of Port 2 by writing to reister FIO2DIR 2 set HIGH the LED driven by P1 28 to do that we load current contents of register FIO1SET i e memory address 0x2009C038 to R3 set to 1 its 28th bit and then put it back into the location at memory address 0x2009C038 i e effectively writing into register FIO1SET LDR R1 FIO1SET we ll not touch R1 anymore so that it keeps this address LDR R3 R1 ORR R3 0x10000000 set to logic 1 bit 28 of R3 STR R3 R1 3 some initializations LDR RO LEDDELAY initialize RO for countdown LDR R2 FIO1CLR we ll not touch R2 anymore so that it keeps this address now the main thing turn the LED P1 28 on and off repeatedly this is
97. nk 2 Red 5 Yellow Blue 3 1 Figure 6 Wiring of the stepper motor To drive the motor we set to logic high low the pins of the MCU in an 8 phase order as shown in the figure below clockwise movement Drive IN4 only Drive IN4 and IN3 Drive IN3 only Drive IN3 and IN2 Lead Wire CW Direction 1 2 Phase Se a Te ge ge ls we Figure 7 Order of driving the first four wires of the stepper For more details on stepper motors take a look at the suggested references 3 and search on the Internet 51 5 Example 2 Control of a stepper motor In this example we control the rotation of the 28BYJ48 stepper motor via the joystick on the MCB1700 board If the joystick is pressed to the left the rotation 1s clockwise and if the joystick is pressed to the right the rotation 1s anti clockwise The files necessary for this example are located in lab5 stepper folder as part of the downloadable archive for this lab This 1s actually the whole uVision project directory Just copy it to keil examples this 1s the code bundle directory of lab 2 Then clean and re build the project Download to the board Connect the stepper motor and the driver board as shown in the figure below using the power supply and the wires provided by your TA Observe operation and comment Figure 8 Stepper motor setup 6 Lab Assignment This lab has no lab assignment no pre lab report no final lab report Instead you should
98. nstantly looking for transmissions that are addressed to it what if the network was very large in size To put it into perspective imagine your computer looking at every single bit of data on the internet to see if any of the millions of data packets are addressed to it This 1s where logical addressing comes in You are probably more familiar with the term IP address however These IP addresses can be subnetted on a network to divide a large network into tiny pieces Instead of looking at every bit of data on the internet logical addressing allows for computers to just look at data on a home network or subnet d Routing A router is a device used to read logical addressing information and to direct the data to the appropriate destination Routers are commonly used to separate networks into portions this greatly reduces network traffic 1f done correctly 89 TCP IP includes protocols that tell routers how to find a path through the network This 1s a vital feature of the TCP IP suite that enables massive LAN connections to be created e Name Resolution Finally we have name resolution If you wanted to conduct a search on the internet you would probably just type Google s URL into your address bar What you probably didn t know is that you aren t necessarily connecting to google com but rather an IP address Instead of having to remember an IP address name resolution allows you to remember Google s name It might not be so
99. o not use joystick use buttons Z and C to increase or decrease the radius of the circle displayed on LCD if joy X axis gt 1907 d dx delta else if Joy x axis lt 90 d dx e delraj else dx 0 x new Xx prev dx it x new gt 320 ragdlus x Dew 320 radius if x new lt 0 radius x new radius if Joy y axis gt 190 dy delta lse if joy y axis lt 90 1 dy delta else dy 0 y new y prev dy if y new gt 240 radius y new 240 radius if y new lt 0 radius y new radius if x new x prev y new y prev must move circle first erase the circle at previous location GLCD SetTextColor Black CRIS draw carcie x preyv y prev radiis then re draw at new location GLCD SetTextColor Yellow CRIS draw circle x new y new radius X prey x new y prev y_new d long delay such that I have enough time to release joystick and have the circle stay at new location this is a hack and should be modified to work nicely and to use rotations delay dirty OxlIDOUU Jj void NunChuck translate data void int bytes IZUSIaveBurrerlPOBT USED 3 7 Joy x axis IZOSlaveButfer PORT USED 0 joy y axis IZOSlayeButfIer PORT USED 1 I2CSlaveBuffer PORT USED accel x axis 2 2 accel y axis IIZCSlaveBuffer IPOBT USED o lt 2 3 accel z axis I2C2olaveBufferlPORT USED 4
100. off and button Z to land Use the joystick to move the drone Read the source code which has comments explaining these controls Observe operation and comment 7 TODOs Lab assignments Change the source code to implement more complex controls Read also the data provided by the AR Drone and do something about it e g display text and or video data on the LCD screen of the board etc Propose something creative and implement it 97 Lab 8 Streaming Video from CMOS Camera This lab is under development 98 Notes on Using MCB1700 Board These notes are meant to help you in deciding whether to adopt MCB1700 board for an undergraduate lab After one semester of using this board 124 students using the boards on a daily basis I have decided not to utilize it anymore in a teaching lab for the following reasons The board does not have its own power supply It does not have a power switch either You will have to attach it to your computer via USB for power It s fragile not sturdy Particularly the COM and CAN ports are weakly attached to the board A few of these ports fell off within a few weeks Pushing and pulling serial cables into the COM ports weakened them very quickly The LCD display is relatively slow While particular MCB1700 samples have a touch screen LCD display there is almost no information on it no examples on how to use the touch screen either The board does not have a protective transparent
101. ombined together and sent as a single data stream The Transmission Control Protocol TCP and the User Datagram Protocol UDP of the Internet Protocol Suite are commonly categorized as layer 4 protocols within OSI 3 Network layer The network layer provides the functional and procedural means of transferring variable length data sequences from a source host on one network to a destination host on a different network in contrast to the data link layer which connects hosts within the same network while maintaining the quality of service requested by the transport layer This layer basically 1s used for routing It tracks location of devices Data travels organized as packets data packets and route update packets 2 Data Link Layer DLL The data link layer provides the functional and procedural means to transfer data between network entities and to detect and possibly correct errors that may occur in the physical layer This layer is usually divided into 2 sublayers 1 the upper one is LLC Logical Link Control and the lower one is MAC Medium Access Control The DLL deals with the movement of data on Local Area Networks LANs The data movement is in the form of frames and forwarded on the basis of hardware address called the MAC address 79 1 Physical layer The physical layer defines electrical and physical specifications for devices It defines the relationship between a device and a transmission medium such as a copper
102. on chip CAN controller are used to build powerful local networks by supporting distributed real time control with a very high level of security The applications are automotive industrial environments and high speed networks as well as low cost multiplex wiring The result is a strongly reduced wiring harness and enhanced diagnostic and supervisory capabilities The CAN block is intended to support multiple CAN buses simultaneously allowing the device to be used as a gateway switch or router among a number of CAN buses in various applications The CAN module consists of two elements the controller and the Acceptance Filter All registers and the RAM are accessed as 32 bit words CAN Controller Architecture The CAN Controller is a complete serial interface with both Transmit and Receive Buffers but without Acceptance Filter CAN Identifier filtering 1s done for all CAN channels in a separate block Acceptance Filter Except for message buffering and acceptance filtering the functionality is similar to the PeliCAN concept The CAN Controller Block includes interfaces to the following blocks see Fig 1 APB Interface Acceptance Filter Nested Vectored Interrupt Controller NVIC CAN Transceiver a separate chip on the MCB1700 board shown in Fig 2 Common Status Registers 32 Figure 3 CAN controller block diagram 1 Kl GND Ok CANI 33V 5 R3 E ND j ll 5 POLO R5 3 10 OR a a PO 1 I N SubD 9M ci
103. ool Configuration Source Code Editor Optimized for Embedded Systems Target Debugging and Flash Programming Accurate Device Simulation CPU and Peripheral You should read this lab entirely before attending your lab session Equally important you should browse related documents suggested throughout the description of this lab These documents and pointers are included either in the downloadable archive for this lab or in the list of References Please allocate significant amount of time for doing this 3 Lab Description a BLINKY 1 Creating a new project 1 First create a new folder called say EE378 2013 where you plan to work on the labs of this course Then inside it create a new folder called lab1 Launch uVision4 Start gt All Programs gt Keil uVision4 3 Select Project gt New uVision Project and then select lab1 as the folder to save in also type blinky1 as the File Name 4 Then select NXP founded by Philips LPC1768 as CPU inside the window that pops up Also click Yes to Copy startup LPCxx s to Project Folder 5 Under File Menu select New 6 Write your code in the and save it as blinkyl c in the same project folder This file as well as all others discussed in this lab is included in the downloadable archive from the website of this course The panel on the left side of the uVision IDE is the Project window The Project window gives you the hierarchy of Target folder and Source Group folder 7 Right click
104. or fiber optical cable This includes the layout of pins voltages line impedance cable specifications signal timing hubs repeaters network adapters etc Data travels in form of digital signals e g 01110001000 The real transmission takes place here 1 e traveling through a medium like cable fiber optic or air 4 The Internet Protocol a k a TCP IP Protocol The Internet Protocol suite is the set of communications protocols used for the Internet and similar networks It is generally the most popular protocol stack for wide area networks It is commonly known as TCP IP because of its most important protocols Transmission Control Protocol TCP and Internet Protocol IP which were the first networking protocols defined in this standard It is also referred to as the DoD model due to the foundational influence of the ARPANET in the 1970s operated by DARPA an agency of the United States Department of Defense TCP IP provides end to end connectivity specifying how data should be formatted addressed transmitted routed and received at the destination It has four abstraction layers see figure below which are used to sort all Internet protocols according to the scope of networking involved From lowest to highest the layers are l Link layer contains communication technologies for a local network 2 Internet layer IP connects local networks thus establishing internetworking 3 Transport layer handles host to ho
105. ples its RX signal until it detects a high low transition Then it waits 1 5 bit periods 24 clock periods to sample its RX signal at what it estimates to be the center of data bit 0 The receiver then samples RX at bit period intervals 16 clock periods until it has read the remaining 7 data bits and the stop bit From that point this process is repeated Successful extraction of the data from a frame requires that over 10 5 bit periods the drift of the receiver clock relative to the transmitter clock be less than 0 5 periods in order to correctly detect the stop bit idle start THX Ao 4 o 1 FUIT oae clock 16x Figure 3 Illustration of signal decoding UARTS can be used to interface to a wide variety of other peripherals For example widely available GSM GPRS cell phone modems and Bluetooth modems can be interfaced to a microcontroller UART similarly GPS receivers frequently support UART interfaces The NXP LPC1768 microcontroller includes four such devices peripherals called UARTs UARTO 2 3 and UARTI See pages 298 and 318 of the LPC17xx User s Manual 1 See also page 27 of the Datasheet 2 UARTO and UARTI of the microcontroller are connected on the MCB1700 board to the ST3232C IC6 which converts the logic signals to RS 232 voltage levels This connection 1s realized from pins P0 2 TXD0 AD0 7 and P0 3 RXD0 ADO0 6 and P2 0 PWMI I TXDI and P2 1 PWM1 2 RXD1 of the microcontroller to the pins 1 0 9 11 and 121
106. pplication Layer APIs A good example of an API is DirectX If you ve ever run a multimedia application and used Windows at the same time odds are you have come into contact with DirectX DirectX 1s made up of many different components that allow programmers to create multimedia applications such as video games There are many types of APIs You may have heard of NetBIOS Winsock or WinAPI among others The world of APIs has also extended to web services You may have heard of a Google API for instance In this case Google allows developers to use its internal functions yet also keeps Google s internal code safe Network Services The Application Layer handles network services most notably file and printing name resolution and redirector services 87 Name resolution is the process of mapping an IP address to a human readable name You may be familiar with the name Google more so than the IP address of Google Without name resolution we would have to remember four octets of numbers for each website we wanted to visit A redirector otherwise known as a requester 1s a service that 1s largely taken for granted It 1s a handy service that looks at requests a user may make if it can be fulfilled locally it is done so If the request requires a redirection to another computer then the request is forwarded onto another machine This enables users to access network resources just like they were an integral part of the local system A user
107. procedure should be done BEFORE and AFTER every firmware upgrade downgrade Open the new Tomato GUI in your browser The default URL is http 192 168 1 1 User root as user and admin as password Then Navigate to Basic Network There are a few settings to toggle in this section Within the Network sub menu do the following settings e First toggle the WAN Internet to Disabled e Second change the values in the LAN section to the following o Router IP Address 192 168 1 2 presumes that the Primary Router IP is 192 168 1 1 that will be the AR Drone o Subnet Mask 255 255 255 0 o Default Gateway 192 168 1 1 the IP of the Primary Router 1 e the AR Drone o Static DNS 191 168 1 1 o DCHP Server Unchecked In the Wireless section of the Network sub menu configure the following settings e Enable Wireless Checked e Wireless Mode Wireless Ethernet Bridge e Wireless Network Mode Mixed 94 e SSID ardrone 291961 This is the name SSID of the network whose Primary Router is the AR Drone In my case it s ardrone 291961 you can check what yours 1s by looking up for wireless networks with your laptop after you power up the drone e Channel The channel of the Primary Router i e 6 2 437 e Security Disabled After the above changes your Tomato s GUI should look like in the figure below Tomato Version 1 28 Status WAN Internet Overview Deren dat Use WAN port for LAN lv Logs Bandwidth LAN R
108. provides most of the components required including a generic SD driver that 1s relatively easily modified to utilize with any typical SPI driver To understand how an application interacts with FatFs consider the example derived from the FatFs sample distribution illustrated in Fig 10 credit http homes soic indiana edu geobrown c335 from where portions of this description have been adopted too This example fragment assumes it is communicating with an SD card formatted with a fat file system which contains file in the root directory called MESSAGE TXT The program reads this file and creates another called HELLO TXT Notice the use of relatively standard file system commands 61 f mount O0 amp Fatfis Register volume work area Eprinti n0pen an existing file Maessage txrt n rc f open amp Fil MESSAGE TET FA_READ if rc xprintf XnType the fila content n for f Read a chunk of file rc f raad EFil Buff sizeof Buff amp br if rc br break Error or end of file for 1 0 1 br 1 Type the data y nyputchar Buff 1 n 1f rc die rc xprintf nClose the file n re f closa EFi1 if rc die rc Eprintf nCreate a new file hello trxt Xn rc f open amp Fil HELLU TXT F WRITE F CREATE ALWATYT3 if rc die rc rprintf inWrita a text data Hello world Xn re f_write amp Fil Hello world r n 14 amp bw 1f
109. ps Ethernet the carrier is LOMHz APPENDIX B How the Application Layer of TCP IP layer stack model works One may ask why an Application Layer is needed for TCP IP since the Transport Layer handles a lot of interfacing between network and applications While this 1s true the Application Layer focuses more on network services APIs utilities and operating system environments By breaking the TCP IP Application Layer into three separate layers we can better understand what responsibilities the Application Layer actually has The OSI Equivalent of the TCP IP Application Layer 1 Application Layer The seventh OSI model layer which shouldn t be confused with the TCP IP stack s Application Layer It supports network access as well as provides services for user applications 2 Presentation Layer The Sixth OSI model layer is the Presentation Layer It translates data into a format that can be read by many platforms With all the different operating systems programs and protocols floating around this 1s a good feature to have It also has support for security encryption and data compression 3 Session Layer The fifth layer of the OSI model is the Session Layer It manages communication between applications on a network and is usually used particularly for streaming media or using web conferencing To better see the concepts of the Application Layer let s take a look at a few examples of the Application Layer in action A
110. r resets the pins that are connected to the LEDs and joystick are automatically configured as GPIO default Hence in our example there is no need to change settings in the pin connect block However it is a good practice to configure these pins before using them Refer to Section 8 1 of LPC17xx user s manual to see which set of pins are controlled by which PINSEL register As an example the five button Joystick 1s connected to pins P1 20 P1 23 P1 24 P1 25 and P1 26 As mentioned earlier it is a good programming practice to configure it Refer to page 109 Section 8 5 4 Table 82 1n LPC17xx User s Manual for more detailed information LPC _PINCON gt PINSEL3 amp 3 lt lt 8 3 lt lt 14 3 lt lt 16 3 lt lt 18 3 20 P1 20 P1 23 P1 26 are GPIO Joystick Set direction Initialize the registers of the peripheral In this step of programming of a GPIO pin we set the I O direction 1 e pin to be used as input or output This is done via FIODIR register see Chapter 9 page 122 of LPC17xx User s Manual for more info There are five LPC GPIOx where x 0 1 2 3 4 macros defined in LPC17xx h The FIODIR is a member variable in LPC GPIO TypeDef C struct in LPC17xx h To set a pin as input set the corresponding bit in FIODIR to 0 All I Os default to input 1 e all bits in FIODIR are default to logic 0 To set a pin as output set the corresponding bit in FIODIR to 1 For example to set pins connected to the
111. r text butter 040 accel x 3x15 GLCD Displaystring 4 10 FI aimee t text burflerj sprinti text buffer 04d accel y axis GLCD Displaystrangio 10 _ Fl aimee L Eext butter Sprinrtr text burrer 040 Accel z axis GLCD Displaystrangibo 10 Fil aire t t sprinti text burfer S DId g Dutton GLCD Daisplaystringi if 10 II quinte L Etext butter SPIIDEI texrt burrer Topid Dutton GLCD DisplaysString 89 10 FI Wines t Jtext buffer ext buffer 46 Lab 5 USB audio Stepper Motor 1 Objective The objective of this lab is to learn through examples about e USB play a youtube song through the speaker available on the MCB1700 board and control its volume via the potentiometer also available on the board e Control of a simple stepper motor using four GPIOs and the joystick of MCB1700 board to set the direction of the rotation 2 USB Introduction USB was developed in the mid 1990s by Compaq Intel Microsoft and NEC joined later by Hewlett Packard Lucent and Philips The USB was developed as a new means to connect a large number of devices to the PC and eventually to replace the legacy ports serial ports parallel ports keyboard and mouse connections joystick ports midi ports etc The USB 1s based on a tiered star topology in which there is a single host controller and up to 127 slave devices The host controller is connected to a hub integrated within
112. r which can be used for sound playback on the PC Potentiometer on the board is used for setting the Volume The files of this example are in keil example USBAudio Launch uVision and open the project clean and re build Download to the board Now start a web browser and play the clip from http www youtube com watch v Tj75Arhq5ho Te audio should play on the speaker of the MCB1700 board Tune the potentiometer listen and enjoy Observe operation and comment This is not an easy project example However take some time to read the source code and try to get a birds eye view understanding of it Start with usbmain c and backtrack the function calls Only with a thorough understanding of the USB theory this source code would be easier to digest Optional Study the USBHID example too 4 Stepper Motor Introduction A stepper motor also referred to as step or stepping motor is an electromechanical device achieving mechanical movements through conversion of electrical pulses Stepping motors can be viewed as electric motors without commutators Typically all windings in the motor are part of the stator and the rotor is either a permanent magnet or in the case of variable reluctance motors a toothed block of some magnetically soft material All of the commutation must be handled externally by the motor controller and typically the motors and controllers are designed so that the motor may be held in any fixed position as well as being rotate
113. rc die rc rprintf AZu bytes written n bw Figure 10 FatFs example 4 Example I Reading from a micro SD card 1GB raw data from fixed physical addresses In this example I simply read raw data from a fixed physical address on the micro SD memory card The SD card has only one file which is a small png image alfaromeo png with size 320x240 pixels Using the free HxD hexadecimal editor I first found that the physical address where the file 1s stored inside the memory is 0x00040000 This is a neat editor which also shows the contents of the file as in figure below 62 ET HHD M BUFFALO ee embedded systems slabsslab5 sd usb alfaromeo pnul mi x E File Edit Search View Analvsis Extras Window x B alfaromeo png DOrrserrh 00 Bi Hz 03 DT B5 06 BI Oe BS DA HB Bb D OE OF pDupgagagagdg 89 50 4E 47 OD O4 14 Of OO OO OO OD 49 45 44 5z PNG ae ar ae eae IHDE noonogoaigd OO 00 ai 40 ao ag OO FO 8 2 OO OO OO FE 4F z 8 85 po ddz 3c OO OO OO 06 62 4B 47 44 FF OO FF OO FF HEGD Y Y 9 00000030 BD AT 93 00 OO OO 09 70 48 59 73 00 OO OF C4 OO amp S pHYs 00000040 OO OE C4 O1 95 2B OF 1B OO OO 20 OO 49 44 41 54 IDAT QOOOOOOSO0 Ye 9C 54 BB CD Ge 2C 49 Ve A5 FY F4 CY CC DD Z3 xeTse In wiCl Oooo006o0 zz 33 6F FD 74 75 FS OF DO OO 67 40 99 A1 90 32 3oytu o B ghHT 2 00000070 23 E4 FB BF O3 iF 80 OB 90 98 41 03 DD 5D 55 F7 ate a Ue dd
114. rd In the future Ethernet will continue to increase in speed Broadcast Network Operation Ethernet is a Broadcast Network hosts are connected to a network through a single shared medium This has the advantage that messages don t have to be routed to their destination as all hosts are present on the shared medium but it does incur another set of problems The main problem which needs to be addressed 1s that of Media Access Control MAC or giving fair access to multiple nodes on a shared medium Collisions When a number of nodes are connected to a single shared medium one of the issues 1s the possibility of two or more nodes trying to broadcast at the same time This 1s called a collision and prevents any information passing along the network because the multiple messages would corrupt each other destroying both There are two main methods for reducing the effect of collisions 1 Collision Avoidance and 2 Collision Resolution Collision Avoidance involves systems which prevent any collisions occurring in the first place such as polling or token passing Collision Resolution or Contention MAC Strategies rely 74 on the fact that collisions will occur and try to cope with them as well as possible Ethernet uses Collision Resolution Below we discuss some collision resolution techniques ALOHA The most basic form of Collision Resolution is to simply allow any station to send a message or packet whenever it is ready to send one This form
115. ress of the source in the same form as above Length This is the length of the data in the Ethernet frame which can be anything from 0 to 1500 bytes Data This 1s the information being sent by the frame Pad 802 3 frame must be at least 64 bytes long so if the data 1s shorter than 46 bytes the pad field must compensate The reason for the minimum length lies with the collision detection mechanism In CSMA CD the sender must wait at least two times the maximum propagation delay before it knows that no collision has occurred If a station sends a very short message then it might release the ether without knowing that the frame has been corrupted 802 3 sets an upper limit on the propagation delay and the minimum frame size is set at the amount of data which can be sent in twice this figure CRC Cyclic Redundancy Check to detect errors that occur during transmission DIX version of FCS or FCS Frame Check Sequence to detect errors that occur during transmission 802 3 version of CRC This 32 bit code has an algorithm applied to it which will give the same result as the other end of the link provided that the frame was transmitted successfully bytes 4 b 1500 b 2 Jb 4 DIX Ethernet Packet bytes 46 1500 Di b b z 4 IEEE 602 35 Frame Figure 1 Structure of an Ethernet frame Ethernet vs 802 3 Although the Ethernet and 802 3 standards are effectively the same thing there are some subtle differences between Ethernet II
116. rotocol dictates and the ACK or NACK is generated by the receiver of the data Start S and Stop P conditions are always generated by the master A high to low transition on SDA while SCL is high defines a Start A low to high transition on SDA while SCL is high defines a Stop There are three types of transactions on the I2C bus all of which are initiated by the master These are write read depending on the state of the direction bit R W and combined transactions The first two of these illustrated in Fig 8 are 1 Write transaction Data transfer from a master transmitter to a slave receiver The first byte transmitted by the master 1s the slave address Next follows a number of data bytes The slave returns an acknowledge bit after each received byte unless the slave device is unable to accept more data 2 Read transaction Data transfer from a slave transmitter to a master receiver The first byte the slave address 1s transmitted by the master The slave then returns an acknowledge bit Next follows the data bytes transmitted by the slave to the master The master returns an acknowledge bit after all received bytes other than the last byte At the end of the last received byte a not acknowledge is returned The master device generates all of the serial clock pulses and the START and STOP conditions A transfer is ended with a STOP condition or with a repeated START condition Since a repeated START condition
117. rtup LPCxx s to the project 2 blinky3 s available in the downloadable archive of this lab as well in an ppendix at the end of this lab 3 C Keil ARM Startup NXP LPC17xx system_LPC17xx c This is needed for the SystemInit function called from within startup LPCxx s We could not add this file to the project provided that we comment out the two lines inside startup LPCxx s that contain SystemInit Build the project and download to target Observe operation and comment At this time you should take time to read the blinky3 s Read it and make sure you understand how the code achieves each task 4 Lab Assignment Modify the assembly program blinky3 s to implement the following design description blink all eight LEDs on the board one by one from left to right repeatedly For each lab with a Lab Assignment you must turn in a lab report in PDF format font size 11 single spacing named lab firstname lastname pdf where is the number of the lab for example in the case of labl must be replaced with 1 which should contain the following sections e Lab title Your name e Introduction section a brief description of the problem you solve in this lab assignment outlining the goal and design requirements e Solution section describe the main technique s that you utilized to develop your solution Include block diagrams flow graphs plots etc here to aid your explanation e Results and Conclusion section
118. s or memory locations are listed on page 300 of the User Manual Utilizing this peripheral is done through reading writing into these registers according to their meaning and rules described in the manual For example one of the 14 registers associated with UARTO 1s Interrupt Enable Register IER Form a C programming perspective LPC UARTO is declared inside header file LPC17xx h define LPC UARTO LPC UART TypeDef LPC UARTO BASE Which also declares what LPC UARTO BASE as define LPC UARTO BASE LPC APBO BASE 0x0C000 Where LPC_APBO_BASE is declared at its turn in the same file define LPC APBO BASE 0x40000000UL This effectively makes LPC UARTO BASE to have value 0x4000C000 which not surprisingly coincides with what is reported on page 14 of the LPC17xx User s Manual Furthermore the Interrupt Enable Register IER contains individual interrupt enable bits for the 7 potential UART interrupts The IER register for UARTO is mapped or associated with to memory address 17 0x4000C004 as seen on page 300 of the LPC17xx User s Manual This fact is captured in the struct declaration of LPC UART TypeDef inside the header file LPC17xx h open this file and double check it As a result in our C programming we can refer to the IER register as in the instruction that we are currently discussing LPC UARTO IER which basically stores represents the address 0x4000C 004 In addition note that IER THRE and IER RLS are decl
119. s as well 18 d Interrupts a 1 encounter An interrupt is the automatic transfer of software execution in response to a hardware event that 1s asynchronous with the current software execution This hardware event is called a trigger The hardware event can either be a busy to ready transition 1n an external I O device 1 e peripheral like for example the UART input output or an internal event like bus fault memory fault or a periodic timer When the hardware needs service signified by a busy to ready state transition it will request an interrupt by setting its trigger flag A thread is defined as the path of action of software as it executes The execution of the interrupt service routine ISR is called as a background thread which is created by the hardware interrupt request and 1s killed when the ISR returns from interrupt e g by executing a BX LR in an assembly program A new thread is created for each interrupt request In a multi threaded system threads are normally cooperating to perform an overall task Consequently we ll develop ways for threads to communicate e g FIFOs and synchronize with each other A process is also defined as the action of software as it executes Processes do not necessarily cooperate towards a common shared goal Threads share access to I O devices system resources and global variables while processes have separate global variables and system resources Processes do not share I O devi
120. s example is an improved version of the previous example Here I simply read the small bmp TODO make it work with png format too image alfaromeo bmp and display it on the 320x240 LCD screen of the MCB1700 board The program in this example can be found inside the uVision project lab5_sd_Icd inside the downloadable archive of lab 5 Clean and build then download to the MCB1700 board Observe operation and comment Study the source code You should see the image displayed on the LCD screen as shown below use the micro SD card from the TA 64 Figure 13 Cris Alfaromeo sports car shown on the LCD display of the MCB1700 board amp 6 Example 3 Manipulate files on the SD card using the FatFs file system The program in this example can be found inside the uVision project lab5 sd fat inside the downloadable archive of lab 5 Clean and build then download to the MCB1700 board Observe operation and comment Study the source code 7 References credits 1 SPI related references About SPI http elm chan org docs spi e html SPI bus see also the references and external links therein http en wikipedia org wiki Serial Peripheral Interface Bus 2 SD memory cards related references How to use MMC SDC cards very popular reference http elm chan org docs mmc mmce e html Modified version of the above http users ece utexas edu valvano EE345M view12 SPI SDC pdf Lab manual http homes soic in
121. s generated and if the TC is reset when a Match occurs see page 492 and 496 of user manual LPC TIM 2MCR 1 lt lt 07 Interrupt on Match 0 compare LPC TIMO gt MCR 1 lt lt 1 Reset timer on Match 0 TCR is Timer Control Register The TCR is used to control the Timer Counter functions The Timer Counter can be disabled or reset through the TCR see page 492 and 494 of user manual LPC TIM P TOR 1 lt lt 17 7 Manually Reset Timer 0 forced LPC TIMO TCR amp 1 lt lt 1 Stop resetting the timer 2 Enable timer interrupt TIMERO IROn is 1 see lpcl7xx h and page 73 of user manual NVIC EnableIRQ TIMERU IBOnj 7 7 See core cm3 h header file 3 Some more one time set up s LPC TIMO 2TCR 1 lt lt 0 Start timer see page 492 and 494 of user manual LPC SC gt PCONP 1 lt lt 15 r 7 7 Power up GPIO seo 1851 CPC _GPIO1 gt FIODIR 1 lt lt 29 Put P1 29 into output mode LED is connected to P1 29 4 infinite loop while 1 Why do we need this if deo nothing return O0 Here we describe what should be done when the interrupt on Timer 0 is handled We do that by writing this function whose address is recorded in the vector table from file startup LPC xx 8 under the name TIMERO IROHandler void TIMERO IROHandler void IR is Interrupt Register The IR can be written to clear interrupts The IR can
122. s generated with Thumb instructions THUMB some directives define where and how the objects code and variables are placed in memory here is a list with some examples AREA in assembly code the smallest locatable unit is an AREA CODE is the place for machine instructions typically flash ROM DATA is the place for global variables typically RAM STACK is the place for the stack also in RAM ALIGN n modifier starts the area aligned to 2 n bytes text is used to connect this program with the C code generated by the compiler which we need if linking assembly code to C code itis also needed for code sections associated with the C library NONINT defines a RAM area that is not initialized normally RAM areas are initialized to zero Note ROM begins at 0x00000000 and RAM begins at 0x2000000 EXPORT is a directive in a file where we define an object and IMPORT directive is used in a file from where we wish to access the object Note we can export a function in an assembly file and call the function from a C file also we can define a function in C file and IMPORT the function into an assembly file GLOBAL is a synonym for EXPORT ALIGN directive is used to ensure the next object is aligned properly for example machine instructions must be half word aligned 32 bit data accessed with LDR STR must be word aligned good programmers place an ALIGN at the end of each file so the s
123. s is achieved by setting to 1 the LSB of IER which in turn is achieved using the mask IER RBR c Source code discussion Please take your time now to thoroughly browse the source code in files uart c and uarttest c files Open and read other files as necessary to track the declarations and descriptions of variables and functions For example in uarttest c we see A function call SystemClockUpdate This is described in source file system LPC17xx c which we locate in the Project panel of the uVision4 IDE Click on the name of this file to open and search inside it the description of SystemClockUpdate This function is declared in header file system LPC17xx h Open these files and try to understand how this function is implemented what each of the source code lines do A function call UARTInit 0 57600 This function is described in source file uart c The declaration of this function is done inside header file uart h Open these files and read the whole code try to understand each line of the code An instruction LPC UARTO gt IER IER THRE IER RLS Disable RBR Based on what s been studied in lab 1 you should know already that LPC_UARTO0 is an address of a memory location the UARTO peripheral is mapped to this memory location Starting with this memory location several consecutive memory locations represent registers associated with this peripheral device called UARTO All 14 such register
124. s on the stability of the potentiometer and other analog components in the feedback circuit Stepping motors can be used in simple open loop control systems these are generally adequate for systems that operate at low accelerations with static loads but closed loop control may be essential for high accelerations particularly if they involve variable loads If a stepper in an open loop control system is overtorqued all knowledge of rotor position 1s lost and the system must be reinitialized servomotors are not subject to this problem In this lab we ll use a so called five wire stepper shown in the figure below This 28BYJ48 stepper motor is driven via a driver board that contains 4 Darlington drivers ULN2003 and 4 LEDs Figure 4 Stepper motor with driver board The diagram below shows the 5 wires connected to the motor which must be plugged into the driver board The connections between the MCB1700 read the source code of the example in the next section and the ULN2003 driver board are e 5V connect to 5 12 V e 5V connect to OV Ground e INI to MCB1700 pin P0 0 e IN2 to MCB1700 pin PO 1 e N3 to MCB1700 pin P0 2 e IN4 to MCB1700 pin P0 3 50 2 BLU COIL 4 E COIL 3 iL COIL 2 ORG COIL 1 RED COMMON STEPPER a e amp amp e l m Figure 5 Connections between drive board and stepper Figure below shows a closer look at the connections of the stepper motor WIRING DIAGRAM Pi
125. simulate relatively short execution times of the program under investigation 9 This 1s a standard method to check that your program works correctly 10 The debugger is a very powerful tool This is only a brief exposure to it we ll revisit it many times later in this course Once you are done with the simulation debug of your program you can stop it by selecting Start Stop the Debug Session from the Debug menu option This stops the show and takes us back to the main uVision window General Purpose Input Output 1 GPIO 1 Fast Interface X PIO FIOIDIR 080000000 ee FTTTTTTT FTTTTTTT TTTTTTTT FIOIMASK ox00000000 FTTTTTTT FTTTTTTT ee FTTTTTTT FIDISET OK6FFFC713 WIV Vi IIT T T Telvlv T T TT T Tv FIDICLA Oxo0000000 FTTTTTTT TTTTTTTT FTTTTTTT FTTTTTTT FIOIPIN OXFFFC713 PER EEEE PRP Pee IT T T9T T TTA Pmsjoerrrczi3 r R vIJjvvivIv WMI Wi ivie e MI Figure 2 Pin P1 29 is checked on off every other second or so Taking it further At this time you should revisit blinky1 c file Read this file it has lots of comments and browse related included files in order to fully understand what 1s what and what it does This 1s very important You should take time to read browse on your own the user s guide of the board the user manual and datasheet of LPC17xx microcontrollers as well as other files included in the downloadable archive of this lab 2 5 Do not attempt to print them as some have gt 800 pages Note tha
126. splay in the Putty terminal Here in this modified example we want to send character by character via CAN send out via CAN2 Tx and receive in via CANI Rx The transmitted and received character should be displayed on the LCD instead of the old ADC value The received character should also drive the 8 LEDs as in example 1 9 Credits and references 0 Textbook Sections 18 4 5 References on CAN 1 LPC17xx user manual Chapter 16 http www nxp com documents user manual UM10360 pdf 2 Schematic Diagram of the MCB1700 board http www keil com mcb1700 mcb1700 schematics pdf 3 Pointers on CAN related information Keil CAN Primer http www keil com download files canprimer v2 pdf CAN Introduction http www esd electronics usa com Controller Area Network CAN Introduction html CAN Information http hem bredband net stafni developer CAN htm CAN Primer http www dgtech com images primer pdf CAN Tutorial http www computer solutions co uk info Embedded tutorials can tutorial htm Jonathan W Valvano s lecture 15 http users ece utexas edu valvano EE345M view15_CAN pdf Note his lectures are based on Stellaris MCU s however the basics about CAN are the same Entry on Wikipedia http en wikipedia org wiki CAN_bus CAN Specification Version 2 0 1991 http esd cs ucr edu webres can20 pdf NXP s Bosch CAN protocol standard http www freescale com files microcontrollers doc
127. ssreresereeeseere 91 Lab 8 Streaming Video from CMOS Camera uusssccutesiveci m bl cula HUE IvE ed EUtE Exc ao t d toto SE EU b Ee Hl cU E du ober itod iik s 98 Notes on Usine MEBI7Z00 BOarO narraio i eb eU M de ace ares get sas ease esis a Madre nul iv dide eid UV sete neste Md suas 99 Lab 1 A Blinky Introduction to C and Assembly Programming 1 Objective The objective of this lab is to give you a first foot in the door exposure to the programming in C and assembly of a program which when executed by the microcontroller NXP LPC1768 an ARM Cortex M3 simply blinks LEDs located on the development board You also learn how to use the ARM Keil uVision IDE to create projects build and download them to the board either Keil MCB1700 or Embest EM LPC1700 2 Pre lab Preparation Optional but encouraged You should plan to work on your own computer at home a lot during this semester You should install the main software evaluation version we will use in this course the Microcontroller Development Kit MDK ARM which supports software development for and debugging of ARM7 ARM9 Cortex M and Cortex R4 processor based devices Download it from ARM s website 1 and install it on your own computer This is already installed on the computers in the lab MDK combines the ARM RealView compilation tools with the Keil uVision Integrated Development Environment IDE The Keil uVision IDE includes Project Management and Device amp T
128. st communication 4 Application layer contains all protocols for specific data communications services on a process to process level It focuses more on network services APIs utilities and operating system environments For example HTTP specifies the web browser communication with a web server See Appendix B for more info Application Presentation Session Process Application m TCP UDP etc Host to Host E Data Link Ethernet ATM TCP IP DoD model OSI Model Figure 5 Comparison of TCP IP and OSI layer stacks Note I Sometimes people mix or are not aware of the meaning and differences between Ethernet and TCP IP Generally speaking they are different levels or layers of a network Ethernet covers the physical medium plus some low level things like message collision detection TCP IP worries about getting a message to where it is going TCP IP is usually found on Ethernet based networks but it can be used on other networks as well Also you can have Ethernet without TCP IP and in fact a lot of proprietary industrial networks do exactly that In addition you can also run TCP IP in parallel with other things like UDP on the same Ethernet connection 80 Note 2 In the seven layer OSI model of computer networking packet strictly refers to a data unit at layer 3 the Network Layer At this layer a packet is also commonly called a datagram The correct term for a data unit at the Data Link Layer
129. t because it is very difficult to cover everything during the lectures and labs you are expected to proactively engage materials related to this course and take ownership of your learning experience This is a necessary but not sufficient attitude to do well in this course b BLINKY 2 Start uVision and select Project gt Open Project then browse to open the Blinky project example located at C Keild60LARM Boards Keil MCB1700NBlinky As you noticed the ARM Kiel software installation contains a folder called Boards that contains design examples for a variety of boards We ll use some of these design examples for the board utilized in this course However as we go you should take a look and play with all these examples try to understand their code Build the project and download to target Observe operation and comment 5 At this time you should take time to read the c files of this project starting with Blinky c Read it and also browse the other files to gain insights into what and how the code achieves different tasks At this stage do not expect to understand everything however please make an effort to see as much as you can c BLINKY 3 In this part of the lab we implement the blinky example by writing a program in assembly language In this example we ll turn on off the LED controlled by pin P1 28 Start uVision and create a new project Add to it the following files 1 When creating the project say Yes to have added sta
130. tart of every file is automatically aligned END directive is placed at the end of each file EQU directive gives a symbolic name to a numeric constant a register relative value or a program relative value we ll use EQU to define I O port addresses AREA text CODE READONLY following lines are to be placed in code space EXPORT main ENTRY 10 EQUates to make the code more readable to turn LED P1 28 on and off we will write the bit 28 of the registers FIO1SET to set HIGH and FIO1CLR to set LOW refer to page 122 of the LPC17xx user manual to see the adresses of these registers they are FIO1SET EQU 0x2009C038 FIO1CLR EQU 0x2009C03C we will implement a dirty delay by decrementing a large enough number of times a register LEDDELAY EQU 10000000 main 1 we want to set as output the direction of the pins that drive the 8 LEDs these pins belong to the ports Port 1 and Port 2 and are P1 28 P1 29 P1 31 and P2 2 6 to set them as output we must set to 1 the corresponding bits in registers page 122 of LPC17xx user manual FIO1DIR 0x2009C020 FIO2DIR 0x2009C040 that is we ll set to 1 bits 28 29 31 of the register at adress 0x2009C020 which means writing 0xB0000000 to this location also we ll set 1 bits 2 6 of the register at address 0x2009C040 which means writing 0x0000007C to this location MOV R1 0x0 init R1 register to O to build address MOVT R1 0x2009 assig
131. te http en wikipedia org wiki Wi Remote Wiibrew Wiimote Extension Controllers http wiibrew org wiki Wiimote Extension Controllers Dangerousprototype http dangerousprototypes com docs Wii Nunchuck quick guide Freescale Semiconductor Tilt sensing using linear accelerometers 2012 11 Wii NunChuck adaptor https www sparkfun com products 9281 APENDIX A Listing of the main source code file for example 3 include lt stdio h gt include lt stdlib h gt include lpcl7xx h include type h include i2c h include GLCD h include CRIS UTILS h wold MunChuck translate data velo j void Nunchuck print data init void void Nunchuck print data void void search for 120 GOSVIOGGSU VOLO define _ FI 1 Use font index 16x24 define PORT USED 1 define NUNCHUK ADDRESS SLAVE OxA4 define NUNCHUK ADDRESS SLAVE2 0xA5 wole tile int Joy x axi volatile int Joy y exis volgtlle int a gel x exis volatlle Int accel y exis volatile int accel s exis 0 0 volatile int z button volatile int 6 D tton extern volatile guint8 t I2CMasterBuffer I2C PORT NUM BUFSIZE BUFSIZE 64 extern volatile uint t I205laveBurffer I2C PORT NUM BUFO IZE extern volatile uint32 t I2CBReadLength I2C PORT NUM extern volatile uint2o2 t IZUWriLeLength il20 PORT NUMI char text buffer s volatile uint8 t ack received ack sent debugging only we ll use delay dirtyi as a software delay function it shou
132. the PC which allows a number of attachment points referred to as ports This 1s illustrated in the figure below T b EA inb EA ib R ub E Hub Sovice Device V l Device Device Device Device Ter Ter2 Ter3 Tird Te5 Te 6 Ther Downstream Traffic rs T M Traffic Figure 1 USB tiered star topology 47 USB is intended as a bus for devices near to the PC up to 5 m For applications requiring distance from the PC another form of connection is needed such as Ethernet USB is a four wire bus requires a shielded cable containing 4 wires that supports communication between a host and one or more up to 127 peripherals The host controller allocates the USB bandwidth to attached devices through a token based protocol The bus supports hot plugging and dynamic configuration of the devices All transactions are initiated by the host controller The host schedules transactions in 1 ms frames Each frame contains a Start Of Frame SOF marker and transactions that transfer data to or from device endpoints Each device can have a maximum of 16 logical or 32 physical endpoints There are four types of transfers defined for the endpoints e Control transfers are used to configure the device e Interrupt transfers are used for periodic data transfer e Bulk transfers are used when the rate of transfer is not critical e sochronous transfers have guaranteed delivery time but no error
133. tion of the 7 layers of the OSI model An example A brief explanation of each of these seven layers follows 7 Application layer The top most layer of the OSI model The primary role of the application layer is that it checks resource usability and synchronization with the remote partner The application layer 1s the closest to the end user which means that both the OSI application layer and the user interact directly with the software application 6 Presentation layer The function of this layer is very critical as it provides encryption services Other services apart from encryption include decryption data compression and decompression 5 Session layer The session layer controls the dialogues connections between computers It establishes manages and terminates the connections between the local and remote application It provides for full duplex half duplex or simplex operation and establishes checkpointing adjournment termination and restart procedures This layer also separates the data of different applications from each other 4 Transport layer The transport layer provides transparent transfer of data between end users providing reliable data transfer services to the upper layers The transport layer controls the reliability of a given link through flow control segmentation desegmentation and error control The transport layer is responsible basically for segmentation and reassembly S amp R The data from upper layer is c
134. ts and runs till the first breakpoint where it stops Notice that P1 29 is 0 To continue the simulation click the icon Step F11 once What happens P1 29 is turned 1 and we stepped with the simulation to the next instruction inside our program 4 Step F11 again more times Observe what happens each time While stepping inside the delay function observe the value of local variable 1 inside the panel labeled Call Stack Locals on the bottom right side of the uVision IDE Notice how 1 is incremented To get out from within the delay function click the icon Step out Ctrl F11 5 Once you get a hang of it stop the simulation Logic Analyzer The debugger includes a logic analyzer that will allow you to study the relative timing of various signals and variable changes It s activated using the button in the debugger Note that you can only use the logic analyzer when you re running in the simulator not on the board The logic analyzer 1s mostly self explanatory Use the Setup button to add channels You can use symbolic names such as FIOIPIN to determine what registers or variables to watch and you can specify a mask value which is ANDed with the contents of the register or variable and a right shift value which 1s applied after the AND operation You can view the result as a numeric value analog or as a bit value At any point you can stop the updating of the screen and or stop the simulation itself and change th
135. tting of data from NunChuck The NunChuck is a slave I2C bus device It has 2 slave IDs for writing 0xA4 and reading 0xA5 data which is shown in Fig 12 a2 0o s o eogjys jJo J muw Figure 11 Slave IDs Communication with the NunChuk consists of two phases an initialization phase executed once in which specific data are written to NunChuk and a repeated read phase in which the six data bytes are read Each read phase consists of two transactions a write transaction which sets the read address to zero and a read transaction Initialize start NunChuk command The initialization consists of two write transactions each of which writes a single byte to a register internal to the I2C slave reg 0xf0 0x55 reg Oxfb 0x00 Normally this done once only The read process consists of writing a 0 and then reading 6 bytes of data Conversion command 0x00 Send this command to get all sensor data and store into the 6 byte register within Nunchuk controller This must be executes before reading data from the Nunchuk 38 Data read command Send the slave ID for reading 0xA5 and wait for the stream data 6 byte from the Nunchuk The joystick data are in the range 0 255 roughly centered at 128 The dynamic range 1s somewhat less than the full range approximately 30 220 The accelerometer data are in the range 0 1023 where 0 corresponds to 2g and 1023 corresponds to 42g The accelerometer can be used both
136. ty will be run in Round Robin when they enter the ready state Higher priority tasks will preempt or interrupt a running task Lower priority tasks will not run Note that it might have been more intuitive 1f Round Robin Timeout had been called Round Robin Task Switching Time If no tasks are ready to run then RTX will execute its idle demon This is located in the file RTX Conf CM c One can insert user code to run during this idle time Configure the project to use RTX Kernel as the operating system Also remember to configure the CPU speed to 100 MHz by means ofthe RTX Conf CM c configuration wizard Compile and download to the board Observe operation and comment 68 Now run a simulation debug session and use the following debug features of uVision e RTX Tasks and System Window Click Debug gt OS Support gt RTX Tasks and Systems This window updates as the RTX runs You can watch task switching and various system and task related information in this window e RTX Event Viewer Click Debug gt OS Support gt Event Viewer Event Viewer provides a graphical representation of how long and when individual tasks run For more details on the above please take some time to read entirely the Keil RTX RTOS The Easy Way tutorial 2 Please read especially section 7 which describes other ways to switch tasks aside from the aforementioned Round Robin S Example 2 Simulating a stepper motor driver a Semaphores MUTE
137. ude e Royalty free deterministic RTOS with source code e Flexible Scheduling round robin pre emptive and collaborative e High Speed real time operation with low interrupt latency e Small footprint for resource constrained systems e Unlimited number of tasks each with 254 priority levels e Unlimited number of mailboxes semaphores mutex and timers e Support for multithreading and thread safe operation e Kernel aware debug support in MDK ARM e Dialog based setup using u Vision Configuration Wizard 4 Example I Creating an RL RTX Application RTX programs are written using standard C constructs and compiled with the RealView Compiler The header file RTL h defines the RTX functions and macros that allow you to easily declare tasks and access all RTOS features 67 The following are the basic steps in the context of this course to create an application that uses RL RTX library 1 Create a new project and use NXP LPC1768 as the target processor 2 Copy the RTX Conf CM c C Keil ARM RL RTX Config to the project folder and add it to your project Note Examples that come with the Keil s uVision installation contain in their own project folders local copies of the RTX Conf CM c which may be different from the one in C Keil ARM RL RTX Config due to their different time stamps 3 Openthe RTX Conf CM c under the Configuration Wizard and set the CPU to 100000000 You need to set the total number of tasks the system can man
138. ure 9 SD card software stack The aforementioned software is typically what is referred as a FAT file system driver One such example is the available widely used FatFs module which with some amount of porting could be utilized with our SPI driver Note that Keil offers a similar module too but it s not free if you tried to compile for example the SD File project you will get an error as you would need an RL license The data on an SD card is organized as a file system cards below 2GB are typically formatted as FAT16 file systems In a FAT file system the first several storage blocks are used to maintain data about the file system for example allocation tables while the remaining blocks are used to store the contents of files and directories An application which wishes to access data stored on an SD Card utilizes file level commands such as open read and write to access specific files within the SD card file system These commands are provided by a FAT file system driver The FAT file system issues commands at the level of block reads and writes without any knowledge of how these commands are implemented A separate SD driver implements these commands Finally the SD driver utilizes the SPI interface to communicate with the SD Card Fortunately it is not necessary to write all of this software One can use of the FatFs generic file system or use licensed ones but for pay like the one from Keil This open source package
139. urther developed by a wide group of developers uIP can be very useful in embedded systems because it requires very small amounts of code and RAM It has been ported to several platforms including DSP platforms The uIP implementation is designed to have only the absolute minimal set of features needed for a full TCP IP stack It can only handle a single network interface and contains only a rudimentary UDP implementation but focuses on the IP ICMP and TCP protocols uIP is written in the C programming language 96 Download and read more details about UIP here uIP downloads https github com adamdunkels uip tags uIP micro IP http en wikipedia org wiki UIP micro IP The uIP TCP IP stack http www gaisler com doc net uip 0 9 doc html main html Some documentation http ucapps de midibox ng doxygen group uip html 6 Example 1 Simple Controls of AR Drone The files necessary for this example are located in downloadable archive for this lab This 1s actually the whole uVision project directory Just copy it then clean and re build the project Download to the board Make all the necessary connections as illustrated in Fig 1 e Power up the AR Drone and place on the floor e Connect MCB1700 board to the WRT54GL wireless router using an Ethernet cable e Connect the NunChuck as done in lab 4 using the NunChuck adaptor additional wires and power supply provided by your instructor Use the button C for take
140. use the extra lab time to work on your projects and on the HW assignment 4 7 Credits and references 1 Micro SD HC cards 2 USB USB Made Simple excellent read http www usbmadesimple co uk index html USB Background http www totalphase com support kb 10047 USB Home http www usb org home http www keil com rl arm rl usbhost asp 52 USB on the go OTG basics http www maximintegrated com app notes index mvp id 1822 http en wikipedia org wiki Universal Serial Bus LUFA http www fourwalledcubicle com LUFA php 3 Stepper motors Control of stepping motors a tutorial http homepage cs uiowa edu jones step Sparkfun tutorial https www sparkfun com tutorials 400 More tutorials http www stepperworld com pgTutorials htm Even more tutorials http www epanorama net links motorcontrol html stepper Stepper Motor 5V 4 Phase 5 Wire amp ULN2003 Driver Board includes detailed specs http www geeetech com wiki index php Stepper_Motor_5V_4 Phase_5 Wire 9926 ULN2003 Driver Board for Arduino Buy it for 2 02 amazing price on Amazon http www amazon com 28B Y J 48 28BY J48 4 Phase Arduino Stepper dp B0089JV2OMv ref pd sim sbs vg 1 53 Lab 5 Supplemental Material SPI and SD cards 1 Objective The objective of this lecture is to learn about Serial Peripheral Interface SPI and micro SD memory cards 2 SPI Introduction Serial Peripheral Interface SPI commun
141. useful when debugging delay dirty Ox100000 I2CWriteLength PORT USED 3 write 3 bytes I2CReadLength PORT USED 0 read 0 bytes I2CMasterBuffer PORT USED 0 NUNCHUK ADDRESS SLAVE1 1 2 I2CMasterBuffer PORT USED OxFB at adress OxFB of NunChuck write I2CMasterBuffer PORT USED 0x00 data 0x00 I2UEDngine i PORT USED jj void NunChuck phase2 read void l this is called repeatedly to realize continued polling of NunChuck uint ij I2CWriteLength PORT USED 2 write 2 bytes I2CReadLength PORT USED 0 read 6 bytes I2CMasterBuffer PORT USED 0 NUNCHUK ADDRESS SLAVE1 I2CMasterBuffer PORT USED 1 0x00 address IzCEnginet PORT USED J delay dirty 0x10000 I2CWriteLength PORT USED 1 write 1 bytes I2CReadLength PORT USED 6 read 6 bytes I2CMasterBuffer PORT USED 0 NUNCHUK ADDRESS SLAVEZ IzCEngine PORT USED when I2CEngine is executed 6 bytes will be read and placed into I2CSlaveButfter I 43 int main void ninrpozr 1j ULnt22s t x prevelou y prev 120 uint322 t x new 100 y newsl2D lnt22 Lr dx e4 dy 4 delta 5 rogiuse ib l1 Initializations of GLED and SER GLCD Init GLCD DetTextCcolor Yellow CRIS draw Gircle 160 120 radius NunChuck print data initi 2 SystemClockUpdate updates the SystemFrequency variable SystemClockUpdate 3 Init I2C devices though we ll use only I2C1
142. usy period then they shall all send as soon as the medium becomes idle leading to a collision e nonpersistent CSMA This strategy attempts to reduce the greediness of 1 Persistent CSMA It again first listens to the medium to see 1f it is idle if so it sends immediately If the medium is busy instead of continuing to listen for the medium to become idle and transmitting immediately it waits a random period then it tries again This means that in high load situations there is less chance of collisions occurring Collision Window A collision occurs when two devices send at approximately the same time But how long does a device have to wait until it knows that its message has not been corrupted by a collision Messages take a certain amount of time to travel from the device to the end of the signaling medium which is known as the propagation delay It would seem that a device only needs to wait for one propagation delay until the message reaches the last receiver to know if a collision has occurred This however is not the case Take for example the following situation A device sends a message which takes 1 propagation delay to reach the last device on the medium This last device on the medium could then send a message just before the original message reaches it 1 e just before 1 propagation delay This new message would take an additional propagation delay to reach the original device which means that this device would not
143. waits for some multiple of 51 2us slots The station first waits for either O or 1 slots then transmits If there 1s another collision then the station waits for 0 1 2 or 3 slots before transmitting This continues with the station choosing to wait a random number of slots from 0 to 2 k 1 1f there have been k collisions in the current transmission until k 10 where the number of slots chosen from stops growing After 16 continuous collisions the MAC layer gives up and reports a failure to the layer above Many companies offer Ethernet MAC EMAC Controllers as SW or HW cores 3 Open Systems Interconnection OSI Model The Open Systems Interconnection OSI model is a prescription of characterizing and standardizing the functions of a communications system in terms of abstraction layers Similar communication functions are grouped into logical layers A layer serves the layer above it and is served by the layer below it 78 Example Application Web Application Presentation HTTP Session 80 Transmision Control n Transport Protocol TCP _ 3 Network Layer 94 WIE Daca EE 3 Network Layer 2 Datalink Layer Daca B P 2 Datalink Layer Network Internet Protocol IP BEEN LU OE Data Link um Data Transmission Meme pae L System Logical Connection in each Layer system 2 I Physical CAT5 NENNEN Realisation of the communication Figure 4 Illustra
144. your old router into a range boosting witfi repeater 95 Buy a used WRTS54GL for about 25 here http www amazon com Cisco Linksys WRT54GL Wireless G Broadband Router dp BOOOBTLOOA 4 Wii NunChuck The Wii NunChuk is an input device with a joystick two buttons and a three axis accelerometer as illustrated in the figure below The three axes X Y and Z correspond to the data produced by the accelerometer joystick X 1s right left Y 1s forward backwards and Z 1s up down accelerometer only Y y C button n Z button a 7 T b Analog joystick NY L1 7 4 L Fi i rer Figure 5 Wii NunChuck The NunChuck communicates via I2C We ll hook the NunChuck to the I2C1 bus of the LPC1768 microcontroller on the MCB1700 board We ll initialize the Nunchuk to a known state and then regularly poll its state We ve already discussed this in lab 4 Please re visit lab 4 as we ll utilize much of it to put together the project herein 5 ulP A Light Weight TCP IP Stack The AR Drone can be controlled via UDP packets We ll do that by utilizing a popular TCP IP stack micro IP a k a uIP The uIP was an open source TCP IP stack capable of being used with tiny 8 and 16 bit microcontrollers It was initially developed by Adam Dunkels http dunkels com adam of the Networked Embedded Systems group at the Swedish Institute of Computer Science licensed under a BSD style license and f

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