Microcontroller Board User Manual
Contents
1. bd Di E D eo power sensor signals However it should be noted E D E fel N E bei e that unless specific lines are connected to signals or E z 2 fe 2 4 driven by the I O ports their indicators may flash O 20 E D E E fa e unpredictably since they are floating cc mm DO oo ES The indicators can be disabled in four columns through the included DIP switch in order to reduce current draw To control the LEDs refer to Figure 5 Slide switch 1 for PORTA PORTE Slide switch 2 for PORTB Slide switch 3 for PORTC Slide switch 4 for PORTD The Microcontroller board also comes with 32 DIP switches to provide input to the pins of the main PIC for debugging purposes Each switch corresponds to an indicator LED Each DIP switch has 3 states 5V Ground and Disconnected The middle position of Figure 6 Signal Switches Personal Mechatronics Lab 8 Microcontroller Board User Manual each switch disconnects it from its corresponding pin The user can choose to set each pin high or low by switching the switch to its corresponding state 3 4 HD44780 Based LCD This peripheral module allows a o HD44780 based LCD display to be easily SE connected to the board Controls are provided for backlight and contrast and Oo BACKLIGHT two equivalent headers have been Figure 7 LCD provided to sup2. firmware which will only be run when the board is in RUN mode It is strongly recommended that the user code is written in Assembly since the user would have full control over the location and length of the user code The user code will Personal Mechatronics Lab 21 Microcontroller Board User Manual be inserted into the firmware between location 0x7D70 and Ox7FEF This means that the user code can be no longer than 640 bytes or 320 instruction words To insert user code into the existing programmer firmware follow these steps 1 Open PICusb and go to Tools gt Append Hex to Firmware 2 An Open File dialog pops up Select the user code HEX file you would like to insert and click Open 3 A Save File dialog pops up Choose a file name and the directory for the new combined Hex file and click Save 5 2 1 1 Writing the User Code When appending custom user code to the programmer firmware the user code must be less than 640 bytes or 320 instructions long The user code must not contain any configuration words The structure of the user code should be as follows include lt p18f2550 inc gt org 0x7D70 begin the user code at address 0x7D70 UserCode end The programmer firmware is built to periodically check pin RC7 When it is cleared the firmware automatically jumps to program memory location 0x7D70 to execute the user code To return to programming mode when the programming switch is set pin RC7 must be
3. otherwise bus conflicts will arise The Microcontroller board is primarily intended to be used with a PIC16F877 A or a PIC18F4620 although most other PIC devices in the PIC16F and PIC18F families are currently supported Additionally some PIC16F and PIC18F devices allow the user to employ an internal oscillator and configure RA6 and RA7 as general purpose 1 O pins If this is intended jumpers JP9 and JP8 must be set as follows upaj E Fen H Short pins 1 and 2 to use external oscillator t el a Short pins 2 and 3 to enable RA6 RA7 Figure 15 Jumper Of course the appropriate configurations must also be set from within the code r H on t E 60606666060600060600600006 TTT OLK EEN PIC DIP40 v PIC DevBugger REU 3 0 Figure 16 Main PIC Module Personal Mechatronics Lab Microcontroller Board User Manual 4 Programming Software 4 1 Overview A Windows application called PlCusb is provided with the Microcontroller board which is designed specifically to communicate with the Microcontroller board hardware Note that Microcontroller board is also fully compatible with MPLAB IDE and PICusb is not needed although recommended except for some advanced applications such as appending a user code to the firmware on the programmer PIC for parallel processing PiCusb currently supports all devices in the PIC10 PIC12 PIC16 and PIC18 families and it is compatible with all Windows pl
4. watch_TRISD Sends the value of TRISD to the TRISD field in the application watch_TRISE Sends the value of TRISE to the TRISE field in the application watch_register_O These macros have an input parameter representing the address watch_register_1 of the file register the user wants to monitor This address is watch_register_2 displayed along with the value of the register on the PC watch_register_3 application One can monitor up to 8 registers registers 0 to 7 watch_register_4 watch_register_5 Example watch_register_O 0x05 watch_register_6 The PC application displays 00000101 and the value of PORTA watch_register_7 beside it 0x05 is the address of PORTA Table 3 Macros available in p2p_macros inc There are two things to keep in mind First the USB sends a packet every 10 ms so this is the time resolution for data updates on the PC application Secondly calling one of these macros is a one time update of the value of the register For registers with regularly changing values it is necessary to call the macro repeatedly either in a loop or at crucial junctures in the code Even so most of the processing in one s code takes place in a matter of microseconds since one operation on the PIC16 takes 400 us thus one cannot actually see and monitor the contents of file registers that change this quickly One solution is to use breakpoints Using the UC it is easy to implement a break
5. PIC to PIC communication for parallel processing This is for advanced users only as it requires that both the master and the slave be programmed Third one can enable PIC to PIC VC communication to enable the usage of PIC18F2550 I O pins by the master PIC during runtime This effectively adds 7 to the main PIC I O pin count Finally an UC capable slave device can be connected to the UC header pins at the top right corner of the board to communicate with the PIC master device 6 2 1 PIC RTC Communication For information on how to use the RTC from the main PIC please refer to section 3 8 6 2 2 PIC to PIC Communication for Parallel Processing To implement parallel processing the user must write the necessary code not just for the master PIC device but also for the PIC18F2550 as the slave device From the master PIC s standpoint programming is greatly simplified by the i2c_common asm file developed for RTC communication and the extended I O pin usage protocol This file is a collection of macros that execute instructions on the hardware level for the I C for instance start transaction write check acknowledge read send acknowledge and stop transaction From the PIC18F2550 s standpoint the programming is more involved as the user must develop the code from scratch The slave code polls or waits for an interrupt signaling the start of an event always initiated by the master device figures out what type of event it is based on the
6. The PlCusb application incorporates a number of additional features designed to increase efficiency and speed up the code development process as well as to provide advanced functionality Write after Import This checkbox when checked will automatically download the code onto the target PIC device after a successful import The user will no longer have to manually press the Write button Update HEX Automatically When this checkbox is first checked it prompts the user to load a HEX file to download to the PIC After the code is downloaded the PiCusb application continuously monitors that HEX file If the HEX file is modified in any way if the HEX file was updated after a successful build in MPLAB PlCusb detects this change and automatically writes the new updated version onto the PIC This function will continue to work as long as the programming switch is set to PRG and the USB connection is not severed This is a useful debugging feature for users who are programming the PIC multiple times in succession After the code is downloaded the user may test the code without flipping the programming switch to RUN mode using the Set MCLR function The only drawback is that the bottom two rows of the keypad will be disabled in this mode Set MCLR This function is a software reset for the target PIC It is useful when debugging and especially when used with the Update HEX Automatically function This feature allows the code on the main PIC to run wi
7. a wide range of implementations from simple MCU operation to parallel processing memory extension serial communication etc Supports 18 28 and 40 pin packages for PIC16 and 18 families In circuit USB High Voltage Programmer compatible with MPLAB IDE Dual USB adaptor power supply ranging from 7 5VDC to 17VDC Debugging Module with 32 indicator LEDs and signal emulation switches Programmer firmware can be modified for extra memory parallel processing and or I O pin extension Real Time Clock peripheral with 32 768khz crystal and battery socket On board HD44780 LCD socket with contrast and backlight controls On board 4x4 keypad socket and signal encoder 40 pin I O bus with ribbon cable connector Changeable oscillator clock LOMHz crystal included On board RS232 peripheral including female socket and level converter VC bus expansion socket On board A2D voltage reference setting Included in the Box The development kit should come with the following items Wi VV WWW VV WV Personal Mechatronics Lab PIC Microcontroller development board CD URL from which to download necessary software drivers and sample codes 2 USB cables 40 pin I O bus cable with header 40 pin I O bus cable without header HD44780 controlled LCD display 4x4 matrix keypad AC DC adaptor unit USB AC DC Adaptor Microcontroller Board User Manual 2 Operation 2 1 Operational Modes The PIC Microcontroller board has three modes of operation as
8. by external circuitry or directly by the PIC by connecting it to one of the ports on the I O bus 3 6 RS 232 DB 9 Communication This peripheral module allows the user to communicate RS232 with a PC through a serial port using the PIC s USART c10 c8 c9 c7 module A MAX232 chip is used as a level converter since MAX232 the USART and the serial port use different voltage levels and a built in DB9 connector allows easy connection to other RS232 compatible devices Note that this module is Figure 9 RS232 Module connected to pins RC6 and RC7 when enabled To enable this module short JP10 3 7 A2D Reference The Microcontroller board has been equipped with two R13 A2D R12 else Jura unconnected the references are disabled Ureiz RA3 Uref RA2 Figure 10 A2D Short JP4 to enable Vref on RA2 Short JP5 to enable Vref on RA3 potentiometers R12 and R13 to set the voltage reference levels for the Analog to Digital Converter ADC To enable these references short JP4 and JP5 if they are both left 3 8 Real Time Clock A Real Time Clock RTC and disk battery allow for off chip timekeeping even when the rest of the board is unpowered The circuit is designed for a DS1307 RTC chip interfaced through UC on pins RC3 and RC4 To enable short JP6 and JP7 Note 1 The DS1307 3V lithium disk battery and jumper shunts are not included with the board Figure 11 RTC Personal
9. checked periodically This can be done with the following code UserCode bsf TRISC 7 set RC7 to input UserLoop btfss PORTC 7 Test RC7 goto UserLoop reset goto Ox2000 Alternatively the code may branch to 0x2000 where the programmer firmware begins Personal Mechatronics Lab 22 Microcontroller Board User Manual 5 2 1 2 Exporting the User Code Once compiled the user must export the custom code into the correct format in order to append to the firmware This is done in MPLAB by the following steps 1 Go to File gt Export 2 A dialog opens with the title Export Hex File Uncheck Configuration Bits EEPROM Memory and User ID 3 Make sure the Program Memory check box is checked Set the program memory to start at Ox7D70 and end at address Ox7FEF Note the end address must not exceed Ox7FEF or PiCusb will reject the hex file 5 Under the File Format tab make sure the format selected is INHX32 6 Click OK and save the exported hex file 5 2 1 3 Loading Modified Firmware onto the PIC18F2550 1 Inthe PlCusb software select Tools gt Download Firmware 2 A dialog opens Select the modified appended hex file and click Open 3 PlCusb will automatically download the new firmware into the PIC18F2550 and then reset 5 3 Re Imaging the PIC18F2550 It is possible to use the bootloader to load custom user code onto the PIC18F2550 but the vectors would have to be remapped to begin at 0x2000 where the programmer fir
10. the I O bus It also receives a regulated 5V from the USB as a power source for all modules Either of these sources can be used as power supply although the Q former is recommended The max current capacity for all D 3 TT C O wo modules combined is 1A enforced by a small replaceable fuse 1 25A TRS size N FERRITE2 The input connector is a female 5 5x2 1mm jack which is 7 I compatible with many commonplace adaptors and wall adaptors of any polarity may be used since the input is Figure 3 Power Supply rectified A single two pole slide switch controls power to the entire board by interrupting the positive power terminal immediately after rectification as well as interrupting the positive power terminal from the USB In the ON position the board is powered as indicated by a red LED in the OFF position all modules are unpowered 3 2 On board USB Programmer 4 0 0 3 Hold while IT powering up Le to enter 2lo 0 1 bootloader BOOTLOAD The Microcontroller board includes an on board USB PIC programmer The programmer operates in High Voltage HEADER IO e G l Programming HVP mode given a supply Ti 2 T2 o R24 l i voltage of 5V It incorporates an internal O a b C17 E 5 W EF CS voltage converter that boosts the 5V e e supply to 12V needed for HVP oor ft ON To enter Programming Mode set the PROGRAMMER Q d slide
11. using the ICSP_OUT header This feature demonstrates the versatility of the PIC Microcontroller board but is highly advanced and not recommended for most users 5 3 1 User Code Considerations Since the firmware requires a specific set of configuration words already set no configuration information should be included in user compiled code It may be assumed that the firmware uses the following configuration settings pragma config pragma config pragma config pragma config pragma config pragma config pragma config pragma config pragma config pragma config pragma config pragma config pragma config pragma config pragma config pragma config pragma config pragma config pragma config pragma config pragma config pragma config pragma config pragma config pragma config pragma config pragma config pragma config pragma config pragma config pragma config FOSC HSPLL_HS PLLDIV 5 USBDIV 2 CPUDIV OSC1_PLL2 IESO OFF FCMEN OFF PWRT 0N BOR OFF BORV 3 VREGEN ON WDT OFF MCLRE OFF LPT10SC OFF PBADEN OFF CCP2MX ON STVREN ON LVP OFF XINST OFF DEBUG OFF CPB ON CPO OFF CP1 OFF CP2 OFF CPD OFF WRTB ON WRTO OFF WRT1 OFF WRT2 OFF WRTC OFF WRTD OFF EBTRB OFF HS osc using PLL 20mhz osc USB clk from PLL CPU PLL 2 Ext osc only No fallback to int osc Enable power up timer BOR disabled in ha
12. value of an VC status register handles it and then loops back to the beginning Microchip s AN735 and AN734 documents are excellent resources for programming and understanding the VC protocol as is Chapter 7 of the AER201 course text where more detailed information can be found on the VC 6 2 3 PIC to PIC Extending I O Set Programming The UC can be used to enable use of the PIC18F2550 s I O pins from the main PIC as if they were its own pins These pins can be controlled using macros available in an include file which are designed to look and behave similar to regular I O control operations in the PIC instruction set This effectively adds 7 additional I O pins for the master PIC but the only downside is the roughly 250 us operation time for write operations and 500 us for read operations compared to 400 ns for regular operations Follow the four basic steps below to use the extended I O pin set 1 Add i2c_common asm and p2p_macros inc to the project Separate include files are included for PIC18F4620 Add include lt p2p_macros inc gt in the code Add call i2c_common_setup in the code Personal Mechatronics Lab 28 Microcontroller Board User Manual 4 Call the macros as needed The firmware called btldr_pgmr_ l2C hex is set up to handle the I O instructions This firmware must be loaded into the programmer before the extended I O set can be used Below is the list of macros available in the macros include file The function and us
13. 10 and 0x78 dig1 where data from the RTC are stored It is important to not overwrite the data in these registers to ensure proper operation Likewise the PIC to PIC communication code uses register 0x70 should not be accessed or modified by the user Sample code is provided to the students which use i2c_common asm and rtc_macros inc as well as p2p_macros inc Personal Mechatronics Lab 32
14. 2 or more exposed pins that can be connected adjacently in pairs using a shunt When two pins of the jumper are connected to each other they are shorted As ann example if pins 1 and 2 in the figure are connected using a shunt then we Figure 2 Jumper say we have shorted pins 2 3 and we have configured the board for use with a P18F type microcontroller as labeled above the jumper 2 4 Interfacing with External Circuits While the board is operating in Executing mode all I O pins of the PIC microcontroller are directly connected to the main I O bus socket Using the provided ribbon cable this bus can be used to interface directly with external circuitry since it provides a 5V supply and ground reference in addition to direct access to the pins of the main PIC Also note that the Keypad peripheral adds an extra pin to the bus for on the fly enable disable control as described in Section 3 5 A detailed description of the pin connections on the ribbon cable is given in Section 3 9 WARNING the 5V supply on the bus is NOT intended as an alternate method of powering the Microcontroller board and NO guarantee is made for the continued integrity of the board in cases of such usage Personal Mechatronics Lab 6 Microcontroller Board User Manual 3 Board Modules 3 1 Power Supply The Power Supply module is designed to take DC input of 7 5V to 17V and output a regulated 5V for all modules to share including
15. A Affordable Comprehensive Transparent ML PERSONAL MECHATRONICS LAB Personal Mechatronics Lab Microcontroller Board User Manual j RTC lout G v ve vey PURERREE RE ees ree Te ep eet sy HI 2012 by M R Emami Microcontroller Board User Manual Table of Contents 1 introductione in E EE EE EN EE a E EK k EEs 3 1 1 TE 3 ev EE 4 13 Tnclud dinthe BOX mniec aer e E O ee aateseeacnees 4 Ze Operati TE 5 21 Operational Modes eegene Eeer 5 2 2 Connecting to the PC for Programming sseesssseseersssssesereererrssesrreerersssesreereeeesses 5 2 3 Customizing Board Operation 6 2 4 Interfacing with External Circuits seeeeeeseeesseereerssrsserereerersssesrreereessresreereeeeeses 6 K NNT Ee ROT TE 7 A WO 7 3 2 On board USB Programmer ee 7 3 3 Debugging beuerteelen saseiasteaaaraeiangaeaees 8 BA HD44780 Based LCD oi deeeeudeteroet eeeeN NENNEN EE Ed EEN cet vrei EE NEES 9 3 5 AXAKEYPAD NEE 9 3 6 RS 232 DB 9 EE 10 37 A2D Referente onesna e E R A E E 10 39 RealTime Clock E 10 3 8 1 Using the Real Time Clock 20 0 ee eccceccsesceseeescecseecsaecaeceaeceaeceseceeeneeeseeeenaeeaes 11 3D Main l O OU 13 SD LR i CU KEE 14 SOU Maim PIG E 14 4 eneen 15 BM EE 15 42 Quick EEN 15 43 Operations E 16 44 Additional Features GEIER 17 AS Sample Code E 19 5 Advanced Programming Topics cceccccsseessecseceeeceseceeceseceeeeeeeeeeeeseeeeeseeeseeeeeeeeceeesaees 21 5A OV RIV IOW
16. Mechatronics Lab 10 Microcontroller Board User Manual Note 2 The RTC module was designed to be used with backup power the 3V disk battery and therefore must have the battery in the socket to ensure consistent operation 3 8 1 Using the Real Time Clock The DS1307 real time clock can be used to keep track of time in seconds minutes hours days months and years The numbers of days in months are automatically adjusted including leap years The hours function allows the chip to keep time in either 12 or 24 hour format with AM PM indicator for 12 hour format The advantage of the off chip timekeeping functionality of the RTC is to free the microcontroller from the task so that it may focus on other tasks For more detail on the DS1307 real time clock please refer to Chapter 7 of the AER201 course notes The RTC communicates with the main PIC microcontroller through the ke protocol and acts as a slave device with a 7 bit address of 1101 000X where X denotes if the transaction is a read or a write In order to use the RTC the main PIC must be configured as a MSSP device or master device for UC The master device is responsible for initiating and controlling the clock pulse for all slave devices including the RTC The configuration code for UC is available to students as two files i2c_common asm and rtc_macros inc Note that these two files were written for PIC16 devices Users may need to modify the source code in order to use these files f
17. age of these macros do not require explanation as they behave almost identically to their counterparts in the PIC instruction set except there are no input parameters Write to PIC18 pins ports Write to PIC18 TRIS Read from PIC18 pins ports e bcf_PORTA A e bt TRlSA A e bttsc PORTA A e bcf_PORTB_3 e bcf_TRISB 3 e bttsc PORTR 3 e bcf_PORTB 4 e bcf_TRISB 4 e btfsc_PORTB_4 e bcf_PORTB_6 e bcf_TRISB_6 e btfsc_PORTB_6 e bcf_PORTB_7 e bcf_TRISB_7 e btfsc_PORTB_7 e bet PORTC 3 e bt TRISC_2 e btfsc_PORTC_2 e bet PORTC_6 e bt TRISC_6 e btfsc_PORTC_6 e bsf PORTIA A e bet TRBISA A e bttss PORTA A e bsf _PORTB_3 e bsf_TRISB_3 e btfss_PORTB_3 e bsf _PORTB_4 e bsf_TRISB_4 e btfss_PORTB_4 e bsf _PORTB_6 e bsf_TRISB_6 e btfss_PORTB_6 e bsf _PORTB_7 e bsf_TRISB_7 e btfss_PORTB_7 e bsf PORTC 3 e bsf TRISC 3 e btfss_ PORTC_2 e bsf_PORTC_6 e bsf _TRISC_6 e btfss_ PORTC_6 e clrf_ PORTA e clrf_TRISA e movf_PORTA_W e clrf PORTB e clrf_TRISB e movf_PORTB_W e clrf_PORTC e clrf_TRISC e movf_PORTC_W e sett PORTA e setf_TRISA e sett _PORTB e setf_TRISB e sett _PORTC e setf_TRISC Table 2 Macros available in the include file to handle extended I O 6 2 4 PIC16 PIC18 Communication for PIC16 Register Watching This application of the VC can be thought of as an example of how one can use PIC to PIC communication It is a finished product which can be used without any actual programming on the user s part The design is sim
18. atforms ce PiCusb File Device Family Programmer Tools View Help Settings Program Memory EEPROM Memory Midrange Standard Configuration Device PIC16F877 User IDs dAdo dels Configuration 3FFF Check Connection Checksum 1BFF Revision lt 06 gt C Write after Import C Update HEX Automatically TI Set MCLR DevBugger V3 found and connected PIC Device Found CS Figure 17 PICusb Application 4 2 Quick Start The user interface for PlCusb is fairly intuitive with reasonable defaults for all settings For those without prior experience with PIC programming software the following steps can generally be used to load the HEX code onto the device Personal Mechatronics Lab 15 Microcontroller Board User Manual Connect the Microcontroller board to the PC as described in Section 2 2 Flip the programming switch to PRG mode Turn on the Microcontroller board Sex D P Click Check Connection on the PlCusb window shown above Wait for the application to detect the Microcontroller board and the PIC device on Click Import or go to File gt Import Hex to load a HEX file 6 Press the Write button to download the HEX file to the PIC device If no error message occurs then the PIC should have been programmed successfully Note if the USB connection is disconnected at any point or the programming switch is flipped to RUN mode the Microcontroller board must be reconnected to the application by
19. controller board must connect to a PC 1 Install the PlCusb programming software before connecting the board a Run the PiCusb setup program Personal Mechatronics Lab 5 Microcontroller Board User Manual An alternative option is to use MPLAB IDE In this case PICusb installation is not required and the Microcontroller board is recognized as PICkit 2 in MPLAB IDE In this manual it is assumed that PlCusb is used 2 Connect the Microcontroller board to the PC using the included USB cable 3 Power the board and turn it on The board can be powered by the USB cable However use of the wall adaptor is recommended for powering the board Set the board to Programming mode Section 2 1 5 Flip the power switch to the ON position Section 3 1 6 The PC should detect the Microcontroller board as a Human Interface Device and install the driver automatically 7 The PIC device on the board is now ready to be programmed Section 4 2 3 Customizing Board Operation The Microcontroller board was designed with versatility in mind To customize the operation of the board several configuration jumpers and switches have been included which must be set by the user Before using the board for the first time please ensure that the jumpers for each module have been configured as desired More information about jumper settings for individual modules can be found in Section 3 For those unfamiliar with jumpers a jumper is a set of
20. d from these registers invoke the rtc_read macro with the address of the register to be read from i e reading seconds register rtc_read OOh The result will be saved in bankO 0x75 of PIC16F877 A or as a two digit BCD number in 0x77 tens digit and 0x78 ones digit ooo0o000o0 0 ooo0oo0oo0o0o0 ooo0oo0o 000 0 ooo0oo0oo0o0o0 3 9 MainI O BUS A 40 pin bus has been provided to allow direct access to each I O pin available on the PIC as well as a special purpose pin for enabling disabling the keypad at runtime see Section 3 5 o O 0 o O o 0 O o o o O The pin outs for the socket and the Figure 13 IO Bus Pin Outs Top View Personal Mechatronics Lab 13 Microcontroller Board User Manual provided protoboard adaptor cable are shown to the left It is important to note that to access RA6 and RA7 jumpers JP8 and JP9 must be properly set as described in Section 3 11 Also the user needs to note that RA6 and RA7 do not exist for PIC16 These pins in the I O bus are intended to be used by PIC18 3 10 I2C BUS An I C bus socket has also been provided to allow a separate 1 C bus to a peripheral device A 10 bin ribbon cable connector not supplied with board should be used for this purpose The pinouts of the socket are shown to the left Figure 14 DC 3 11 Main PIC Device This section of the board has several sockets for PIC devices of different sizes Only one socket may be occupied at a time
21. d put on another Microcontroller board Personal Mechatronics Lab 26 Microcontroller Board User Manual 6 PEC PIC to PIC Communication 6 1 I2C Overview The I C is a widely used serial bus specification that allows communication between one or more master devices with one or more slave devices The master is the device that selects the receiver by transmitting the address of the slave device and initiates all transactions read or write between itself and the slave The ke implementation on the Microcontroller board includes one master the main PIC and three slave devices the RTC chip the PIC18F2550 and the VC female header pins at the top right corner of the board which can connect to an external I7C slave device 6 2 Using the GC The hierarchical chart below shows the possible applications of the UC bus as it is implemented on the Microcontroller board Master Slave device device RTC chip PIC18 programmer 12C bus module Figure 20 Using UC Bus Application a External timer Parallel processing PIC18 I O pin access PIC16 Pin Monitoring Custom application As shown above there are four ways in which the I C bus on the Microcontroller board can be used First one can access the RTC module for timing purposes through the VC Personal Mechatronics Lab 27 Microcontroller Board User Manual bus Second one can set up
22. follows Programming Executing Bootloader Used to load compiled HEX code onto the main PIC device To enter this mode flip the slide switch of the programmer module to the PRG position In this mode the VPP PGC and PGD pins of the main PIC device are disconnected from the main I O bus and connected instead to the programmer module A PC application such as MPLAB IDE or PlCusb can be used to control the execution of code in this mode This is the primary operational mode of the board To enter this mode flip the slide switch of the programmer to the RUN position In this mode All I O pins of the main PIC device are connected to the I O bus and code executes freely In addition if the parallel processing firmware is used the user defined code on the programmer PIC begins to execute simultaneously to main PIC For advanced users only This mode allows the user to re program the firmware of the programmer module via the USB link The bootloader mode also allows the user to restore the programmer firmware in case it becomes corrupt This mode can be entered either from the PC application or manually To enter this mode manually turn off the board power supply then hold the BOOTLOAD button on the programmer module while turning the power supply back on More details on using the bootloader feature can be found in Section 5 3 2 2 2 Connecting to the PC for Programming In order to load HEX code to the PIC device the Micro
23. g module This is a project that demonstrates the analog to digital conversion ability of the PIC16 It takes in a voltage input and controls the flashing speed of an LED according to that voltage This is a project designed to test the UC bus connection between the PIC16 and PIC18 It allows PIC16 to toggle RB6 on PIC18 through the IC bus This is a project designed to demonstrate the parallel processing ability of the Microcontroller board The PIC16 can be loaded with any code while PIC18 will toggle RB6 This project tests the Analog to Digital converter module on the PIC18F4620 This sample uses the internal oscillator of the PIC18F4620 and the Phase Locked Loop feature PLL which runs at 32MHz This project tests the PWM module of the PIC18F4620 It generates a 20kHz signal with 50 duty cycle The signal is output through the CCP2 pin RC1 This project is similar to LCD project for PIC16 with different display messages This project is the same as the PortTest project for PIC16 This project is the same as the Keypad_LCD project for PIC16 This project is the same as the RS232 project for PIC16 Personal Mechatronics Lab 20 Microcontroller Board User Manual 5 Advanced Programming Topics 5 1 Overview The programmer module is fully functional out of the box and can be used to program PIC devices of families PIC16F and PIC18F However since the module itself is built around a PIC18F2550 it is capable of much m
24. geen 21 5 2 Coding Firmware Modifications lt ieqsccessesanessnassnaedenasoansiiendesaaeanveigenaataacssanaonedeaseens 21 5 2 1 Modifying Run Mode ccceecceesseesseeseeceseceaeceaeceeeceaeceseeseeeseneseneeeaeeeaeeeaecaeesaees 21 5 3 Re Imaging the PIC18F2550 A 23 5 3 1 User Code Considerations 0 ccccecccesccesscesseeseeeeeeeeaceeseeeaeecaaecaeceaeceaeeeaeeeaeeees 24 5 3 2 Restoring to Original State 25 D PG PIC to PIC Commupicatin ege ENEE i 27 OM TACO VORVICW a enee E AE ee eege 27 6 2 Using the 2 Ce TE 27 6 2 1 PIC RTC Communication 28 6 2 2 PIC to PIC Communication for Parallel Processing ceceeeecceseeeeeereeeeeeee 28 6 2 3 PIC to PIC Extending I O Set Programming 28 6 2 4 PIC16 PIC18 Communication for PIC16 Register Watching eee 29 6 2 5 PIC 12C Bus COMMUNICATION 04 2 sd ssid esecsansdevestedacseseedecesnsdevcasesaceessuedsoveseadaees 31 6 3 Important Note About i2c_common asm and Its Macros 0 cccccsseesseeteetteetteeenees 31 Personal Mechatronics Lab 2 Microcontroller Board User Manual 1 Introduction 1 1 Overview The PIC Microcontroller board development board was designed as a complete mobile solution to the PIC development including a full speed USB programmer and a number of peripheral modules such as LCD Keypad Real Time Clock A2D and RS232 and ke serial ports One especially useful feature of the board is the debugging module which monitors all pin states and a
25. llows the user to emulate inputs to the PIC The board is ideal for students as it can be used to develop and test codes quickly and effectively It is also easy to track down and repair all components on the board Applications can vary from an exclusive development platform to a full scale embedded processing control system used in a final design RAG 4 FEDS Ho wie O Ge ee G BOOTLOAD A2D_ a2 EI poi FERRITE Gr IER R z 7 Ems Er S Ri ST G t Uret RA3 Uret RAZ ve RS232 a cio C8 c9 C7 GK MAX232 S yy d EC RTC POWER PROGRAMMER oe HE le e el RE HEADER IO Jap ccl C2 GI ei vd es i 2 w a GS 113 0048 O SS e gt O e BACKLIGHT C DevBugger REU 3 0 PIC DIP40 PIC DIP28 PIC DIP18 Q keveat T Om BUFFER E E 3 O 2 a S RBS 4x4 Keypad E zg E 6 E ENCODER E Ed o E is E EI E fe e JP3 EI 2 z E E e m OO EI o0 S56 off Figure 1 The PIC Microcontroller board Personal Mechatronics Lab 3 Microcontroller Board User Manual 1 2 WV WM VW WW Y VVVVV VV WM 1 3 Features Open modular and simple design for learning purposes Supports
26. mon_setup subroutine this subroutine is located in i2c_common asm Simply type call Personal Mechatronics Lab 12 Microcontroller Board User Manual 8 i2c_common_steup It is suggested that this subroutine to be called at the top of the main source file You only need to call this subroutine once NOTE Call this subroutine before initializing the LCD Invoke the RTC macros when needed in the user code to use the RTC Here is the memory map of the RTC registers ADDRESS BIT 7 BIT 6 BIT 5 BIT 4 BIT 3 BIT 2 BIT 1 BIT 0 FUNCTION RANGE 00H CH 10 Seconds Seconds Seconds 00 59 01H 0 10 Minutes Minutes Minutes 00 59 12 SC 10 1 12 02H 0 i Hours Hours AM PM 24 PM Hour 00 23 AM 03H 0 0 0 0 Oo DAY Day 01 07 04H 0 0 10 Date Date Date 01 31 05H 0 0 0 10 Month Month 01 12 Month 06H 10 Year Year Year 00 99 07H OUT 0 0 SQWE 0 0 RS1 RSO Control 08H 3FH Ge 00H FFH 56x8 0 Always reads back as 0 Figure 12 RTC memory map Register 00h to 07h are used for timekeeping 07h is used to generate square waves but this function is not included 08h to 3fh are general purpose registers and can act as extra memory To reset register OOh to 07h to zero simply invoke the rtc_resetAll macro To set a register invoke rtc_set macro with the address of the register and the data to be set as parameters to the macro i e setting seconds to zero rtc_set OOh OOh To rea
27. mware begins Instead if the user wishes to erase the entire eas programmer code including the bootloader a second high QQagae voltage programmer such as another Microcontroller board Figure 19 ICSP_Out may be used The Microcontroller board was designed such that the PIC18F2550 can be programmed without taking it out of its socket The second row of the PIC18F2550 I O header shown on Figure 18 contains all the pins required to program the PIC18F2550 A second header near the programming switch called ICSP_OUT shown in Figure 19 is the output from the programmer This header will allow the programmer to program any external PIC To use this header to program other boards the basic firmware without parallel processing must be loaded onto the PIC18F2550 and the programming switch must be set to RUN mode This disconnects the header from the main PIC on the Microcontroller board Furthermore the same ICSP_OUT header can be used as an input to program the main PIC on the Microcontroller board as long as the programming switch is set to PRG The Pin out of this header from left to write is as follows 1 Vpp MCLR 2 Ven 3 Vss GND Personal Mechatronics Lab 23 Microcontroller Board User Manual 4 ICSPDAT PGD 5 ICSPCLK PGC 6 NC If the user has another high voltage programmer at hand and wishes to use both PICs as parallel processors he she could program the PIC18F2550 using its I O header and the other PIC
28. n in the same bank after the macros are invoked It is strongly advised to re select the memory bank after calling the macros or use the banksel directive in MPLAB The i2c_common asm and the macros are for PIC16F877 and will not work directly with PIC18F4620 However these files can be ported to PIC18 code with minimal modification The I C communication code does take up some of the user s resources Since the macros call subroutines one stack level will be taken The VC code will be stored in program memory and will take about 200 to 300 memory slots of the available 8192 slots on the PIC16 without any macro calls This includes both the real time clock 1 C algorithm as well as the PIC to PIC algorithm Keep in mind that macros are simply directives in MPLAB and macro code can be thought of as copied and pasted into the user s code whenever invoked This will result in the user code being much longer than anticipated especially if these macros are invoked linearly or not in loops over and over again The RTC code will take up 8 general registers in the PIC16 data memory 0x71 to 0x78 in bankO to store data used during operation These registers are defined as a cblock in Personal Mechatronics Lab 31 Microcontroller Board User Manual i2c_common asm and the corresponding names are for convenience s sake The actual code uses the actual register address The main registers that are relevant to the user are 0x75 DOUT 0x77 dig
29. or PIC18 i2c_common asm This source file contains the lowest level algorithm to deal directly with the UC protocol It also contains the algorithm to deal with communication between the microcontroller and RTC as well as for the PIC to PIC VC communication This file must be included in the user s MPLAB project rtc_macros inc This file must be included in the MPLAB project as well as the user code wherever these macros are called This file contains three primary macros that can access all the timekeeping functions of the RTC These are Macro rtc_resetAll Input parameters none Output none Description When invoked this macro resets all the time keeping registers on the RTC memory or resets time to zero Macro rtc_set address data Personal Mechatronics Lab 11 Microcontroller Board User Manual Input parameters Takes in 2 literal parameters the address of the register being written to and the data which will be written Output none Description This macro will initiate a write event to the RTC The user must specify the address which will be written to i e the seconds register which holds the time in seconds and the data which will be written to the specified address Macro rtc_read address Input parameters address to be read from Output DOUT 0x75 dig10 0x77 dig1 0x78 Description This macro will initiate a read event to the RTC and read data from the specified address The data from the RTC will be
30. ore than programming the main PIC device To take advantage of this untapped potential several extra features have been implemented to give the user full control over the device Note that to take advantage of the following features the parallel processing firmware must be loaded on the PIC18F2550 Bootloader A USB enabled bootloader has been programmed into the device s firmware allowing the user to re load the programmer with their own HEX code Mode Detect The programming firmware can detect whether the programmer switch is set to PRG or to RUN via pin RC7 For more details see Section 5 2 1 VC Bus An TC bus connecting the PIC18F2550 to the main PIC device may be enabled by shorting JP14 and JP15 This allows communication between the two devices opening up the possibility of parallel processing PIC18 Bus A secondary I O bus socket has been provided giving access to the unused pins on the PIC18F2550 The pin outs for this socket are shown to the right Since this is an advanced Q Y OI Q lt UI I feature of the board no cable is provided Figure 18 PIC18 Header 5 2 Coding Firmware Modifications There are two options for modifying the programmer module s firmware 1 Append user code to the programmer firmware to modify run mode behaviour 2 Use another HVP programmer to re image the entire PIC18F2550 chip 5 2 1 Modifying Run Mode Using this option users can append their own code to the original programmer
31. ould be done by advanced users only View Program Memory and EEPROM Memory The Program Memory and EEPROM memory are shown in their respective tabs below the menu bar Once a HEX code is loaded the contents of the HEX code can be viewed through these tabs There is an Enable checkbox on each of these panels that is used for enabling writing the HEX code to the PIC If unchecked the code will not be downloaded to the target PIC upon pressing the Write button Only one of the two checkboxes can be unchecked at any time The user may also modify the HEX code in these tabs although this is not Personal Mechatronics Lab 18 Microcontroller Board User Manual recommended for most users The HEX code may be viewed in HEX format or ASCII format 4 5 Sample Code The PICusb package contains 12 sample projects located in the Samples folder where the application is installed There are four sets of sample codes one for each one of PIC16F877 PIC16F887 PIC16F1937 and PIC18F4620 Some PIC18 samples may use the internal oscillator block All the PIC16 samples are assumed to run with a 10MHz crystal oscillator The samples are described below PIC16 Samples DS1307 RTC This project demonstrates the code necessary to interface with the DS1307 real time clock IC not included on the Microcontroller board using the UC module of the main PIC device Also it demonstrates RS232 usage the program first resets the RTC s seconds to zero and then re
32. peatedly reads the time and transmits over RS232 to a PC The baud rate is 9600 with 8 bit data and no parity KeyPad_LCD This project demonstrates the basics of interfacing with the Keypad and LCD modules of the Microcontroller board anything that is typed on the keypad is immediately displayed on the LCD Port Test This project is a simple test program which can be used to quickly verify that MPLAB PICusb and the programmer module of the board each function correctly If this program executes correctly then each of the Debug LED s should flash sequentially when the board is placed in RUN mode Note that RA4 on PIC16 devices will not turn on unless pulled up by either a debug switch or an external resistor since it is an open drain output RS232 This project demonstrates two way RS232 communications it sends a welcome message to the computer and then repeatedly echoes any data received back to the computer As with DS1307 RTC the baud rate used is 9600 with 8 bit data and no parity LCD This is a simple project that displays a message on the LCD Personal Mechatronics Lab 19 Microcontroller Board User Manual Input Test ADC Evtended IO Parallel_Processing PIC18 Samples A2D PWM PIC18_1 Port Test PIC18 PIC18LCD_Keypad USART This is a project designed to test the input switches on the debugging module It sets all pins to input so the user can use the DIP switches to control the LEDs on the debuggin
33. ple 1 PIC16 The user calls one of a number of macros to update the contents of a port or register during the running of their PIC16 code 2 PIC18 The data is sent to the PIC18 through IC which is sent to the USB 3 PC The application available through the website displays this information There are four easy steps to set up this functionality 1 Add i2c_common inc and Register_Watcher_macros inc to the PIC16 project 2 Add include lt Register_Watcher_macros inc gt in the code 3 Add i2c_common_setup in the code 4 Call the macros as needed Personal Mechatronics Lab 29 Microcontroller Board User Manual 5 Make sure the programmer PIC18 has the firmware with register watching Below is a table listing the macros contained in p2p_macros inc which must be called by the user s code Macro Description watch_PORTA Sends the value of PORTA to the PORTA field in the application watch_PORTB Sends the value of PORTB to the PORTB field in the application watch_PORTC Sends the value of PORTC to the PORTC field in the application watch_PORTD Sends the value of PORTD to the PORTD field in the application watch_PORTE Sends the value of PORTE to the PORTE field in the application watch_TRISA Sends the value of TRISA to the TRISA field in the application watch_TRISB Sends the value of TRISB to the TRISB field in the application watch_TRISC Sends the value of TRISC to the TRISC field in the application
34. point subroutine that stops the PIC16 s operation and waits for the user to press the programmer module s bootloader switch before continuing Presented below is the implementation breakpoint lt call whatever watching macros you want here for e g watch_PORTA gt bet TRISA D sets pin the bootloader switch is connected to to input Personal Mechatronics Lab 30 Microcontroller Board User Manual btfsc_PORTA_O waits for the user to press the switch and pull RAO low goto 1 if RAO is not low keep looping lt put a bit of a delay here gt so that the PIC is not at the next breakpoint by the time you release the switch return continue with the program The user should call this subroutine at key junctures in the code to stop execution transmit register values read them from the PC and then push the bootloader switch when ready to continue operation 6 2 5 PIC I2C Bus Communication Implementing communication between the PIC as the master and an external slave device is for advanced users only The user would have to program both the master and slave codes in addition to ensuring that the hardware for the bus connection is set up properly 6 3 Important Note About iZc_common asm and Its Macros The RTC and PIC to PIC macros call subroutines in i2c_common asm and will need to access SFRs on the main PIC Therefore it will require switching memory banks Invoking these functions will not guarantee that the user will remai
35. port different LCD orientations Up Down facing HD44780 PIC I O Pin Since the HD44780 protocol supports RS RD2 either 8 bit or 4 bit data transfer modes R W GND E RD3 D4 RD4 configured to use 4 bit mode in the D5 RD5 interest of conserving I O pins The D6 RD6 HD44780 interface pins have been D7 RD7 Table 1 HD44780 I O Map the Microcontroller board has been mapped to the PIC I O ports as shown in Table 1 3 5 4x4 KEYPAD Since 4x4 keypads are commonly used in been T microcontroller applications this module was included to simplify the required interface Two BUFFER equivalent headers provide a socket for the keypad in different orientations and a MM74C922 hex encoder simplifies the polling process while reducing pin requirements The EI w fa O o E D data pins for the encoder are connected to PORTB lt 7 4 gt and the data available pin active high is connected to RB1 JP3 allows the user to enable or disable the Figure 8 Keypad keypad Short pins 1 and 2 to disable keypad Short pins 2 and 3 to enable keypad Personal Mechatronics Lab 9 Microcontroller Board User Manual The Keypad module can also be enabled or disabled on the fly through the special KPD pin on the I O bus If this is desired JP3 should be left unconnected If KPD is set high the keypad will be disabled and if set low the keypad will be enabled Note that KPD can be controlled either
36. pressing the Check Connection button before programming Any time that the Check Connection button is pressed the HEX file must be reloaded 4 3 Operations The following is a description of common operations that may be performed on the PIC device used in the Microcontroller board Import loads a HEX file into memory for loading onto a PIC device or for verification against the code already loaded onto a PIC device Read is used to read the current program loaded into the target PIC device This program can be retrieved and stored in a HEX file Write programs the currently loaded HEX code into the target device Several options for this operation are available By default all aspects of the HEX file are programmed into the device however checkboxes in the Program Memory tab and the EEPROM Memory tab can allow sections of the HEX file to be programmed Verify reads the contents of the PIC device and compares it against the loaded HEX file If any differences are observed an error is given and the operation fails Erase performs a bulk erase of the device effectively returning it to its factory state In some cases this may fix a device that appears faulty Check Blank is used to verify that the chip is indeed blank This is useful after performing an Erase chip operation to verify that the operation succeeded Personal Mechatronics Lab 16 Microcontroller Board User Manual 4 4 Additional Features of PICusb
37. r of the installation directory e btidr hex HEX file containing the original bootloader e btldr_pgmr hex HEX file containing the original bootloader and programmer firmware This is the basic firmware without support for parallel processing e btldr_pgmr_I2C hex This file contains the bootloader programmer firmware as well as the default user code containing the 1 C functions for extended UO capabilities This part can be replaced by another user code using PlCusb see Section 5 2 1 1 e btldr_pgmr_reg_watcher hex This file contains the bootloader programmer firmware as well as the register watcher code containing the UC functions for PIC16 pin monitoring ability The firmware can be restored by activating the bootloader This is done by turning off the power switch and holding the BOOTLOAD pushbutton switch while turning the power switch back on The programmer is in bootloader mode if the BUSY LED flashes at just below 1Hz The PICusb application will automatically detect that the Microcontroller board is in bootloader mode At this time the original firmware may be downloaded with the Download Firmware function If the bootloader is corrupt another high voltage programmer is needed to restore the PIC18F2550 to its original state The PIC18F2550 can be programmed in circuit through Personal Mechatronics Lab 25 Microcontroller Board User Manual its I O header as described in section 5 3 or taken out of its socket an
38. rdware BOR on 2 05V min setting USB internal vreg enable RE3 MCLR disabled TMR1 low power mode disabled PortB A D off on reset CCP2 on RC1 Reset on stack overflow Disable extended instruction set CD off Code Protect Boot EEPROM not protected WWriteprotect 000 to 7FF No other write protect Config not protected EEPROM not protected Table reads not protected Personal Mechatronics Lab 24 Microcontroller Board User Manual pragma config EBTRO OFF pragma config EBTR1 OFF pragma config EBTR2 OFF The user code should not modify the state of any I O pins other than the ones on the I O header Also PORTC lt 7 gt is used for PRG RUN mode detection as described in Section 5 2 1 As such it must ALWAYS be set as an input Pins RB1 and RBO are used for an optional PIC to PIC DC bus which can be enabled connected by shorting jumpers JP14 and JP15 in the programmer module 10K pull up resistors on these lines are already provided on the board The specifics of UC communication between the programmer and the main PIC are left to the user 5 3 2 Restoring to Original State In case the firmware on the PIC18F2550 becomes corrupted by the user code the programmer can be restored to its original state The PICusb software package includes two HEX files containing the original firmware of the Microcontroller board programmer These are located in the Programmer Firmware folde
39. saved to data memory general purpose register 0x75 or DOUT as an 8 bit binary number For the convenience of the user this data will also be converted into a two digit ASCII number and the tens digit will be stored in 0x77 or dig10 and the ones digit will be stored in 0x78 or digi This is advantageous because HD447780 based LCDs only display ASCII numbers In order to use these files simply add them to your existing MPLAB project If you do not know how to make a project in MPLAB use the MPLAB Project Wizard under Project to generate a project To do this follow these steps 1 2 3 4 Copy i2c_common asm and rtc_macros inc into your project directory Open MPLAB and load the project where the RTC is to be used Go to View and make sure Project is checked In the Project window where all the files in the project are listed Right click Source File and select Add Files Select and add i2c_common asm in your project directory In the Project window where all the files in the project are listed Right click Header Files and select Add Files Select and add rtc_macros inc in your project directory In any source files in which the user code calls the RTC macros you must use the include directive at the top of the page to include rtc_macros inc Simply type at the top include lt rtc_macros inc gt Before using the RTC macros you must enable and configure the main PIC as a master I C device To do this simply call i2c_com
40. switch to the PRG position and to enter Executing mode set the slide switch to the RUN position To enter bootloader mode see Section 5 3 2 turn off the board power supply hold the BOOTLOAD button and turn the power supply back on Figure 4 USB Programmer Personal Mechatronics Lab 7 Microcontroller Board User Manual For advanced users wishing to modify the programmer source code in order to take advantage of parallel computing an VC link may be established between the PIC18F2550 of the programmer module and the main PIC device To physically establish the electrical connection between the two devices jumpers JP14 and JP15 must be shorted Users who want to use the PIC18F2550 s I O pins from the main PIC during runtime also need to short jumpers JP14 and JP15 This function also makes use of the UC bus implemented on the Microcontroller board between the main PIC and the programmer PIC Please refer to Section 6 2 for more information on these capabilities 3 3 Debugging Module The Debugging module allows the user to monitor the states of the I O pins of the main PIC device via oF Ww E a S 32 indicator LEDs These indicators are fully eg E s buffered so they do not impact the voltage levels of O O D D Ei a ei E the signals they are monitoring in other words E D bi E ei they can safely monitor the logic states of low O20 0202 020 E D oO E
41. thout flipping the programming switch to RUN mode When checked the PIC18F2550 programmer PIC holds the main PIC in a reset state When unchecked the programmer releases the reset and the main PIC device will begin to execute code Note that this reset when the programming switch is set to PRG will override the pushbutton reset switch This function can also be reached from Programmer gt Hold Device in Reset Export Hex This function located under the File menu allows the user to save the HEX code currently loaded onto PICusb into a HEX file To check what HEX code is currently loaded onto PICusb go to the Program Memory or EEPROM Memory tabs This feature is mainly used in conjunction with the Read function for saving the HEX code read from the PIC device into a file Recent Files PICusb preserves the 4 most recently loaded HEX files for faster access under the File menu Personal Mechatronics Lab 17 Microcontroller Board User Manual Manual Device Select This function is used for some PIC10 and PIC12 devices that do not support automatic device detection This function is found under the Programmer menu Once activated a device family must be chosen from the Device Family menu and a particular device must be selected from the Select Part dropdown box To exit this mode a device must be selected Enable Code Protect and Enable Data Protect These two functions are found under the Tools menu These functions set the configura
42. tion data to enable code or data protection During development do not enable these features as they may be permanent Use VPP First Program Entry This function is used when the configuration or ID of the target PIC device becomes corrupt and the programmer is unable to identify the device This function forces the programmer to program the target PIC which may correct the code on the target PIC Append Hex to Firmware This feature is an advanced peripheral feature of the application that allows custom user code to be added to the programmer firmware It is used for PIC to PIC parallel processing and is further described in section 5 2 1 Download Firmware This function allows firmware to be downloaded onto the programmer PIC18F2550 The firmware may be the default firmware or a custom firmware modified with custom user code It evokes the bootloader to allow the PIC18F2550 to program itself This feature will corrupt the programmer firmware if used improperly and is therefore recommended for advanced users only Configuration This feature allows the user to view the configuration settings for the target PIC device and change them if the user wishes It does not provide any information about the function of each configuration bit It is not recommended for most users to change the configuration settings through this function all configuration settings should be specified in the code Modifying the configuration settings in this fashion sh
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