AVRcam User's Manual
Contents
1. JROBOT 19 JROBOT Next left click on the Capture button in the Command Bar This will take a snapshot of the camera s current field of view and display it A complete image acquisition takes about 4 seconds to complete Once all the image lines have been sent to the AVRcamVIEW application the complete image will be shown If the image appears fuzzy the lens on the camera module can be adjusted to focus the image better File View Device Help Connect Disconnect Configure Serial Set Registers Ping Capture Enable Tracking L System Messages capture Frame 11 07 2004 10 24 28 oo Ri Bae ke Sad File Frame Data 47 Frame Data 48 Frame Data 49 Frame Data 50 Frame Data 51 Frame Data 52 Frame Data 53 Frame Data 54 Frame Data 55 Frame Data 56 Frame Data 57 Red 240 Green 16 Blue 16 Frame Data 58 Frame Data 59 Frame Data 60 Frame Data 61 Frame Data 62 Frame Data 63 Frame Data 64 Frame Data 65 Frame Data 66 Frame Data 67 Frame Data 68 Frame Data 69 Frame Data 70 Frame Data 71 i Clear Once a useful image has been captured the user can then select a color from the image to track by moving the mouse pointer over the region of interest in the completed image on the right Notice that the red green blue values for the pixels underneath the mouse pointer are updated below the image to indicate what color combinati2. Bes 18 6 3 1 KAN Mode sic iiss tak ater aie ait ee ee ka Oa etait ge ee aaa ae ia 18 6 3 2 Frame Dump Mode sivaicaisiaasaits urinaire apee ka sgatinanasss E SEEI 18 6 3 3 Color Tracking Modecor itr orinter s e yen s n t kon RoE oios 18 6 4 Testing the AVRcam User Interface v2 5 n ke e sa eya gidon pe aie epe 18 6 5 Testing the AVRcam with AVRcamVIEW 00 2L00lleteeeeereeooeseoosasooosasooosaanoonon 19 6 6 How Lighting Affects the AVRCAM 0 0Li0ieeseeeeeroooeasaooeanooosanooosanooosnooosnaooooon 23 7 Advanced Development with the AVRCAM eeeeeeeerroooroen 24 7 1 Programming the AV RCA esye epei aie ki atak i den ki e ai adapte e kape Da gete 24 OPC KL kn ket te sa e n to e epa e ene oti ee 25 8 1 AVRcam Bill of Materials 71022 pace oa evoke A ae opa aes an 25 8 2 AVRcam Parts Cross Reference 1ccj2c0n aksii asse osds esye eban rout donnen aooe daso manse asatebanann 26 Yo TC CINE B ke aleka ede tal ak tol ap bi oi aa ne ia 27 9 1 Complete AVRcam Command Protocol c cc ceeeceesseceeseececeeeeeceeeeecseeeeeeteeeees 27 WN Paola telat aaa ie E at e a Aili el n e ar see eka 31 JROBOT 2 1 Revision History JROBOT Date Version Author Update 11 06 2004 1 0 John O Initial release 12 02 2004 1 1 John O Added pictures and instructions for cable 02 07 2005 1 2 John O assembly Added more detail in section 7 for in system reprogramming verified all previously marked CHECK items
3. ET Payload none Response ACK if command successfully received NCK if command not successfully received Supplemental Response Packets lt The camera begins to generate color tracking packets in hex to indicate what color blobs are found in each frame There are NO spaces between bytes in a color tracking packet The current color map will be used to map the sampled pixel values into actual colors gt Byte 0 OXOA Indicating the start of a tracking packet Byte 1 Number of tracked objects 0x00 0x08 are valid Byte 2 Color of object tracked in bounding box 1 Byte 3 X upper left corner of bounding box 1 Byte 4 Y upper left corner of bouding box 1 Byte 5 X lower right corner of boudning box 1 Byte 6 Y lower right corner of boudning box 1 Byte 7 Color object tracked in bound box 2 Byte x OxFF indicates the end of line and will be sent after all tracking info for the current frame has been sent Example The user wants to begin tracking the colors set in the color map User ET r AVRcam ACK r AVRcam 0x0A 0x05 0x04 0x12 0x09 0x36 0x38 0x01 0x25 0xFF End of line X upper left corner color2 Y lower right corner of box1 X lower right corner of bounding box1 Y upper left corner of bounding box1 X upper left corner of bounding box1 color1 number of tracked blobs Indicates start of color tracking packet AVRcam 0x0A 0x05 0x06 0
4. GCC a port of the standard GCC C compiler to the AVR family of microcontrollers Version 3 2 of the GCC compiler was used for development though later version should also work The compiler is bundled into a package known as WinAVR which is a simple installer that sets up the entire GCC development environment under Windows This software can be downloaded at http winavr sourceforge net The AVRcamVIEW PC application was written entirely in Java and utilizes the RXTX serial package for Java available at http Awww rxtx org This software can be expanded to add new buttons and associated commands to the GUI as well as other image processing features if needed The Java 1 5 development environment was used for this effort Finally it is important to check http www jrobot net often for new updates regarding the system as well as additional discussion in the forums section at http Avww jrobot net Forums 7 1 Programming the AVRcam Each time the AVRcam powers up the yellow debug LED will blink four times and stay powered on During this blinking period the user has the opportunity to re program the AVR through the 10 pin STK200 300 programming header The programming session must be initiated during this blinking period Otherwise it is possible for the programming to fail since the lines on the mega8 used for programming MISO MOSI SCK or only guaranteed to be in the required tri state level while the yellow LED is blinking If program
5. RAM for storing images and large amounts of power while images are being processed The end result is a fairly complicated expensive system that is out of reach for many developers who have moderate image processing requirements The AVRcam was designed to fill this gap in image processing The AVRcam shown in Photo 1 is a real time image processing engine that utilizes an Omnivision OV6620 CMOS image sensor mated with an Atmel AVR mega8 microcontroller to perform all of the image processing tasks It can be thought of as a vision sub system with a well defined interface that is accessible through a standard serial port This interface provides high level post processed image information to a primary system PC another embedded controller BASIC Stamp etc to utilize This removes the burden of performing the image processing on the main system and allows the developer to concentrate on how to use the high level image data to perform the task at hand Photo 1 Front view of the AVRcam v1 1 The AVRcam provides an assortment of capabilities Track up to 8 different colorful objects at 30 frames second Configure the system to recognize up to 8 different user defined colors Provide real time tracked object statistics number of objects color of objects bounding box through a standard serial port Tracked image resolution of 88 x 144 pixels at 30 frames second Perform full resolution color image dumps Dumped image resoluti
6. complete Both completed cables are shown in the following photo JROBOT 10 JROBOT 4 2 Assembly Instructions for the AVRcam The AVRcam can be assembled with only a basic knowledge of soldering and electrical components The complete parts placement diagram can be found in Figure 1 O MEGAB P sae GOPYRIGHT 200 JE OROT Figure 1 AVRcam v1 2 circuit board layout JROBOT JROBOT 4 3 Before Beginning Assembly As the board is being assembled it may be helpful to the user to secure each component to the circuit board before soldering it down Small strips of tape work very well to hold the components in place while soldering All components are placed on the BACK side of the board with the exception of the 32 pin dual row camera header which is placed on the FRONT side of the board See Photos 2 and 3 for reference Photo 2 also provides a reference for right left top edge bottom edge when assembling the board Power 7 20 V AVR m itch DC in e a Top Edge do TTL level SIGI Serial LED Connector Power RS232 TTL LED selector jumper JP2 Test Points GND 19 VIE Jovy s ee SIG1 O ao ara aad ann A Connector Right Left Edge Edge AVR Bottom Edge mega8 ISP jumper JP1 Photo 2 BACK side of an assembled AVRcam After each component is placed and soldered it may be necessary to clip off any excess portion of the leads for the components JROBOT 12 Mounting Holes JROBOT 32 pin Cam
7. 0 AVRcam v1 2 Schematic JROBOT Appendix C psi P 2 PH ak MAX232 GND PSS b R4 f RAN R20UT RIN RIOUT 4 4K so LPS TOUT TAN y at ToT TAN evo 057 010 1 AVR_ISP AVR_ISP 2 o ch SiG1 Q e AVRISPB w AVRISPA gt c2 AVRISP a AVR _ISP 6 C1 AVR ISP P w AVR ISP 8 L un Cit Ioga E AVRISP B AVR_ISP 19 GND GND a 8 POU l ah Re L a GND 10K siG2 IC4 Hi la MOUNT PAD ROUND3 2 o gt H2 Sn g 2 POOIRXD POTD MOUNT PAD ROUND3 2 vec 4 EINTE vec pas Esa 5 1 PD3INTI c3 c4 vec vse ESE BY poaxcivTo L H3 Ri Hees ES A1 Posmi h ag MOUNT PAD ROUND3 2 pi esuo pcr ERANO O4uF 0 4 uF H4 eal 10K _ Uva F604 PD7JAIN1 a Qiioun PAD ROUND3 2 GND EE e k i RG k 14 2 te EHL SDA ws PRES T Paniicr GND 4 01 se uva PERE T esticcta 10K ws LER 18 PB2 ss 0c18 i uve ERS TO PB3MOSIOCZPBIXTAL2TOSC2 Nse Uw PB4MISO i PBS SCh PBB XTALITOSC1 EXCL Pco ADco z PWON PC1JADC1 avec e AGDA YA Peajapca AREE i ney sep ys PES 2 pc3janca senp H ze anoa ve PER SE PCAJADCAISDA enp Y7 POSJADC
8. 0 This complete range is sent down to the AVRcam when the user left clicks on the Send button The median value for each color channel is then summed together to generate the displayed color in the Color Index row Thus for the above example the color being selected by the user is a shade of purple If you prefer to use the old Color Map edit the shortcut to the AVRcamVIEW and add the parameter Davr old color map right after javaw exe The new Color Map is only available to users running JRE 1 5 0 and higher If a lower version of the JRE is used then the old Color Map will be used and is displayed below Color Map System Colors rT IiITITI 1 2 DODD Ce ee s COO oe ae COREE EEE JIG Re Se le 0 DODODOOOO COCO 20 LEE DODODOOOO DONC 1 A Auto Check _ Clear Column s Clear All Reset Send JROBOT 21 JROBOT Now that the color map has been set left click on the Enable Tracking button in the Command Bar This will start the camera tracking any color that has been programmed into the Color Map Note The Command Bar has certain operations disabled while the system has tracking enabled The Tracking window is displayed to show each tracked object s bounding box as well as each objects color shown with the filled in box in the center of each bounding box As objects that match the colors in the color map move through the AVRcam s field of view the Tracking window updates in real time to show t
9. JROBOT AVRcam User s Manual Version 1 4 JROBOT JROBOT Table Of Contents Ly REVISION HISO ae feat a ian adan eka bi da en bean po aka kas noes 3 2 Copyright Licensing Disclaimer INfO reeeeeeoooooooorsssanonoooonon 4 gt MAEOCU CUO 2 loan at ka pe a aa Oo ane kn on a eke eet ae 5 4 Building the AVRCIUN yo ie sise year esseye toa 7 4 1 Assembly Instructions for the Serial and Power CablesS vrereeeeroooronooon 7 4 1 1 Assembling the Power Cable a ae vie ee dabitid io bik sa dan pandan da vese 7 4 1 2 Assembling the Serial CAbl ive is iisavessstee be sessss se saaa n s pstodanaye sou dote ssanskasoesde 8 4 2 Assembly Instructions for the AVRCAM 0 0 0Lleeeeveeetooronoooooonoooooaoosonooonoonoe 11 4 3 Before Beginning ASSEMOI Yn ksatite s a aa yan n Mondo ais a ka ga eee 12 44 Validating the AVRCam Assembly eceeccecseccecssceceeececeeeeecseeeeceseeeseteeeees 14 5 Installing the AVRcamVIEW PC SOoftWafe uveeeeooevooooen 15 5 1 Windows Installation e e io e foi de ka in Bane ae kai ep n 15 527 Emuk stat lawon cen loa a on e tot acs versie Stach as ss acon ee DA ken da dako bo aie NA 15 6 Communicating with the AVRCAM 000L0ieeeeeeeeeeereeersssenoonoooon 16 6 1 Electrical Interface tothe VRC ai vot 20 iG escent Sn ease sucess ken bon dey dis an 16 6 2 Protocol Overview onc bal vesyon cielo eee boua eko ka eden ee Rede 16 6 3 AVRcam MO de sie sects n n ct ara ee at eg Aes
10. Rcam v1 0 r Finally in addition to the normal command response protocol the AVRcam has different modes that can be invoked that enable additional information packets to be sent from the AVRcam to the host system asynchronously These modes will always be invoked by a standard command response pair For example to enable the color tracking mode the user sends and ENABLE TRACKING command ET to the AVRcam The AVRcam responds with a positive acknowledgement if the command was received successfully The AVRcam then begins to send tracking packets back to the host system to be processed This example is illustrated below lt host system gt ET r lt AVRcam gt ACK r AVRcam formatted tracking packet containing hex characters AVRcam formatted tracking packet containing hex characters AVRcam formatted tracking packet containing hex characters The above example shows how the ACK from the AVRcam is followed up with multiple tracking packets for as long as there are objects being tracked or until the DISABLE TRACKING command is sent to the AVRcam This example is also the first time that a non ASCll printable character could potentially be sent to the host system The tracking packets contain 8 bit hexadecimal values between 0x00 and OxFF in a well defined packet format described in Appendix B These tracking packets will not be viewable with a normal terminal emulator since terminal emulators only display ASCII characters t
11. Response Packet Example The user wants to update registers 11d with a value of 14d and 13d with a value of 26d in the OV6620 camera module User CR 11 14 13 26 r AVRcam ACK r NOTE This command can cause the AVRcam to not function properly if certain registers within the OV6620 are modified Use caution when modifying the registers JROBOT 27 JROBOT Mnemonic OpCode DF Payload none Response ACK if command successfully received NCK if command not successfully received Supplemental Response Packet Raw color frame dump packets Byte 0 OXOB indicating the start of raw color data line Dump a Frame Byte 1 line number in hex indicating which line number is being sent Byte 2 178 176 hex pixel stacks where a pixel stack is structured as follows Each pixel stack consists of a one byte value where the high nibble represents one color value green and the low nibble represents another color value either red or blue The pixels on the camera are arranged in Bayer format High nibble Green pixel value of the even rows Low nibble Red or Blue pixel value of the odd rows Byte 179 OXOF indicating an end of line Note The AVRcam will send a total of 77 frame dump packets to the host system where each packet contains information about two consecutive rows of image data each time the DF command is received Example The user w
12. S SCL PC6 RESET le2 RESET PBS MEDAR o K kai XTAL2IPB4 FS aye SA XTALNPB3 SND TI sanpB2 LI 2N3904 vee MSO PB1 2 R2 GND MOSIJPBO ND TINVI2P a Li 4 GND JROBOT 31
13. The first thing to do with the AVRcamVIEW application is to configure the serial port for 115 2 kbps 8 data bits 1 stop bit and no parity 8N1 These parameters are set through the Configure Serial button on the Command Bar Next left click on the Connect button which will allow the user to select which COM port on the PC to use Once this is set the first thing the AVRcamVIEW software does is to ping the camera to determine if it is present If the AVRcam is not present then the response timer associated with the ping command will expire after 5 seconds and a timeout message will be displayed to ther user This indicates that the ping was not received by the AVRcam This could be due to incorrect serial settings wrong COM port disconnected serial cable or powered off AVRcam It is now time to send a user initiated command from the AVRcamVIEW application to the AVRcam Left click on the Ping button in the Command Bar The user should see the MessageViewer display update showing that it sent the PING command followed by the response sent back by the AVRcam either ACK or NCK If no response is received from the AVRcam the command will time out after 5 seconds It is also possible to manually inject a NCK into the system by pressing CTRL N on the keyboard AVRcamView File View Device Help nect Disconnect Configure Serial Set Registers Ping Capture Enable Tracking System Messages Ping ACK
14. Updated the schematic board layout and assembly instructions so they match version 1 2 of the hardware the only change is that the 0 1 uF caps got new Cxx numbers on the schematic 02 21 2005 1 3 John O Brent T Updated section 6 5 to include the new Color Map selector mechanism Also updated the DF command in the Appendix to more accurately describe how the frame dump works 09 6 2005 John O Added in parts list cross reference to appendix JROBOT 3 JROBOT 2 Copyright Licensing Disclaimer Info AVRcam Hardware and Embedded Software Copyright 2004 John Orlando AVRcamVIEW PC Software Copyright 2004 Brent Taylor All material in this document is Copyright 2004 by John Orlando Both the AVRcam embedded software and the AVRcamVIEW PC software are licensed under the GNU General Public License If interested in an alternative licensing scheme please contact John Orlando at john jrobot net The AVRcam system is distributed in the hope that it will be useful However no warranties either expressed or implied are made regarding the operation use or results of this system The AVRcam should not be used in any life critical applications JROBOT 4 JROBOT 3 Introduction Image processing has always been a task left for systems that have a considerable amount of computing resources to provide any reasonable functionality These systems typically require fast processors lots of
15. able through the serial connector NOTE It is important to make sure that the ribbon cable is lined up with the teeth in the 9 pin serial connector to ensure proper connection Once completed the cable should look like the following JROBOT 8 JROBOT 2 Next the opposite end of the ribbon cable needs to have some of its wires shortened The serial connection only needs 3 of the 9 transmit receive and ground signals Cut and strip the opposite end of the cable so that it looks like the following photo So 3 Connect the three metal crimp connectors to the exposed end of the wire using a crimp tool or a pair of needle nose pliers Again a small amount of solder can be used to secure the connection if needed The result should look like the following photo 3 v 4 Insert the three metal crimp connectors into the white Molex housing ensuring that the catch on each connector locks securely in place NOTE This step requires that second and fourth wire from the red strip in the ribbon cable are crossed over before inserting into the housing as shown in the following photo JROBOT 9 JROBOT cr EN En 5 Slide the heat shrink tubing over the Molex connector so that it protects the ribbon cable where it connects to the housing Apply heat to this tubing with either a heat gun ora hair dryer so that it shrinks and seals up this cable as shown in the following photo The serial cable is now
16. al with this situation is to enable the auto white balance However this can also cause other colors to appear slightly different than their normal color The best situation is to experiment with the system in different environments to determine what seems to work and what doesn t regarding lighting conditions JROBOT 23 JROBOT 7 Advanced Development with the AVRcam The AVRcam project is an open source development effort Both the embedded software running on the AVRcam as well as the AVRcamVIEW PC application are both available in source form licensed under the GNU General Public License This allows any developer to have access to the source to make modifications or add new functionality to the system as needed according to the terms of the GPL The AVRcam provides the standard 10 pin AVR ISP header which is compatible with the STK200 and STK300 programming cables common among AVR enthusiasts A suitable programming cable can be purchased at http www jrobot net that connects to the parallel port of any PC This in system programming also requires software that is capable of programming the mega8 such as the open source AVRDUDE programming software http savannah nongnu org projects avrdude or the free PonyProg software http www lancos com prog html This provides a standard way to update the flash memory on the mega8 as well as modify the fuse settings on the mega8 if needed The AVRcam software was developed using AVR
17. am and thus no tracking packets can be sent back to the host system the mode still persists The only way to exit this mode is to send the DISABLE TRACKING DT command to the AVRcam This causes the system to go back to the Idle Mode 6 4 Testing the AVRcam User lnterface The easiest way to get started with the AVRcam user interface is to use a serial terminal emulator running on a PC such as Hyperterminal or minicom as the host system This allows the user to send simple commands to the board and view the responses sent by the board First power down the AVRcam if it is currently powered on Then plug in the DB9 9 pin connector on the serial cable into the serial port on the back of the PC Plug the other end of the serial cable into the AVRcam s 3 pin RS232 header see Photo 4 Turn on the power switch to the system Next start up a terminal emulator on the host PC such as Hyperterminal or minicom The terminal emulator should be set up to run at a baud rate of 115 2 kbps 8 data bits 1 stop bit and no flow control Make sure that the terminal sends only a carriage return when the user presses the Enter key some terminals default to sending carriage return line feed when the Enter key is pressed Also turning local echo on will allow the user to see the commands as they are typed in From the terminal emulator send a PING command to the AVRcam by typing PG followed by hitting the Enter key Pressing the Enter key is
18. ants a single frame of image data sent to them actual RGB values User DF r AVRcam ACK r AVRcam 0x0B 0x01 0x83 OxD3 0x4A lt 173 more pixels gt OxOF blue value end of line green value red value green value Note No spaces exist between data blue value green value Line Number Indicates start of frame dump packet AVRcam 0x0B 0x02 0x83 0xD4 0x3A lt 173 more pixels gt 0x0F AVRcam 0x0B 0x48 0x83 0xD4 0x3A lt 173 more pixels gt 0x0F Note The hex values 0x0B through OxOF are reserved and will not be used in the data stream other than to indicate the starting and ending marks of a line of pixel data In addition the frame dump packets can be sent out of order which is why the line number is included in the packet The user should be able to reassemble the lines in their proper order for displaying the complete image Mnemonic Get AVRcam Software Version Number OpCode GV Payload lt none gt Response ACK if command successfully received NCK if command not successfully received Supplemental Response Packet lt The camera will send a string indicating the software version number gt Example The user wants to determine what version of software is running on their AVRcam User GV r AVRcam ACK r AVRcam AVRcam v1 4 r JROBOT 28 JROBOT Mnemonic Enable color blob tracking OpCode
19. ed between VCC and GND disconnect the power from the circuit by turning the power switch off Then insert IC1 IC2 and IC3 into their appropriate sockets on the board making sure that the notch on the IC matches the notch on the socket see Photo 2 It may be necessary to bend the legs on each IC slightly to make it fit into the socket Once the ICs are inserted switch the power switch back on Using a voltmeter measure the voltage between VCC and GND again making sure that it is still close to 5 V If not DISCONNECT the power cable immediately and go back and check all connections on the board Once the proper voltage is measured between VCC and GND turn the power switch off Turn the board over and insert the OV6620 camera module into the 32 pin female header on the FRONT of the board see Photo Remove the lens cap on the camera if it is still connected Finally turn the power switch back to the ON position The green LED should light up and then about two seconds later the yellow LED should blink three times and then stay turned on This indicates that the board has successfully powered on and is running If not turn the power switch back to the off position Wait a few seconds and try turning it on again If the yellow LED still doesn t light up disconnect the power cable immediately and re check all connections on the board 5 Installing the AVRcamVIEW PC Software The enclosed CD contains the both the Windows installer a
20. era Connector C3088 Camera Module with OV6620 Photo 3 FRONT side of assembled AVRcam with camera detached The AVRcam should be assembled in the following order 1 2 3 Insert and solder R1 R2 R3 R4 R5 R6 R7 R8 and R9 Insert and solder C1 C2 C3 and C4 None of these capacitors are polarized so their orientation is not critical NOTE It may be necessary to bend the leads to these capacitors slightly inward so that they will fit into their holes Turn the board over and insert the 32 hole dual row female camera header on the FRONT side of the board This should be the only component placed on the front side of the board with it being soldered on the BACK side of the board When finished turn the board back over to continue working on the BACK side of the board The DIP sockets for holding IC1 IC2 and IC3 will be connected next It is important to note that the actual ICs will be added to the circuit at the end of the assembly process after everything on the board has been tested Again DO NOT INSERT IC1 IC2 OR IC3 UNTIL AFTER THE BOARD HAS BEEN TESTED Otherwise there is a potential to destroy the ICs 4 5 Insert and solder the two 14 pin DIP sockets to form a 28 pin DIP socket for IC1 Make sure that the notch on the socket is properly oriented pointing to the left edge of the board Insert the 8 pin DIP socket into the board for 1C2 Solder it down ensuring that the notch on the socket is prop
21. erly oriented pointing to the bottom edge of the board JROBOT 13 JROBOT 6 Insert the 16 pin DIP socket into the board for IC3 Solder it down ensuring that the notch on the socket is properly oriented it should be pointing to the left edge of the board 7 Insert and solder IC5 to the board Make sure that the front of this chip where it says LM2937 is facing the top edge of the circuit board 8 Insert and solder the AVR_ISP programming header Make sure that the CENTER notch in the header is not facing the outer edge of the circuit board If the AVR_ISP programming header also has an offset notch this should be facing the outer edge of the circuit board 9 Insert and solder C5 C7 C8 C13 and C15 Note that all of these capacitors ARE polarized and the positive terminal should line up with the positive sign shown on the circuit board 10 Insert and solder T1 the 2N3904 transistor Make sure that the flat edge of the transistor is facing the bottom edge of the circuit board 11 Insert and solder the two 3 prong male Molex headers on the right edge of the board These headers are used to communicate with the serial port one for TTL level signalling and one for RS232 level signalling Make sure that the tall back of each header is closest to the right edge of the board 12 Insert and solder the only 2 prong male Molex header that is used to deliver a power source to the circuit Make sure that the tall back o
22. external host system through a UART based serial port This serial port can operate at both TTL voltage levels as well as RS232 voltage levels depending on the configuration of Jumper2 JP2 near the right edge of the board see Photo 2 If the AVRcam will be communicating with a PC that uses standard RS232 voltage levels the JP2 jumper should be inserted on the board If the AVRcam will be communicating with another microcontroller or another system using TTL voltage levels JP2 should be removed from the board The pinouts for the both the RS232 and TTL serial ports is shown in Photo 4 gO TTL Port Rx connect to Tx on external controller Tx connect to Rx on external controller Gnd RS232 Port Gnd ge Ti connect to Rx on PC TANM A MAN ee ee AAA NE KE a ee Photo 4 Pinouts of TTL and RS232 serial ports The protocol used to communicate with the board is a very simple command response interface Commands are sent to the AVRcam through transmit line TX on the serial port and responses are returned from the AVRcam through the receive line RX on the same serial port It should be noted that no flow control is used on the AVRcam The only three lines needed to communicate with the system are the TX RX and GND Currently the AVRcam only supports a baud rate of 115 2 kbps with 8 data bits 1 stop bit and no parity The entire AVRcam command protocol is described in Appendix B 6 2 Protocol Overview A typical AVRca
23. f the header is closes to the top edge of the board 13 Insert and solder LED1 and LED2 the green and yellow LEDs The yellow LED sits closer to the top edge of the board and the green LED goes right under it The LEDs are polarized so their orientation on the board is important The longer leg of each LED is the anode and should be inserted so that the anode is closer to the bottom edge of the board for each LED 14 Insert and solder both JP1 and JP2 the two 2 pin jumpers Take extra care to make sure they are standing perpendicular to the board when soldered down since they can easily wiggle while performing the soldering Once these jumpers are solderd down place the actual jumper inserts to connect each jumper together 15 Insert and solder the 3 pin male header that provides Vcc GND and SIG1 close to the left edge of the board Again take extra care to make sure this header is standing perpendicular to the board when soldering it down 16 Insert and solder the 1 pin male header that provides SIG2 near the right edge of the board This signal is an extra signal that can be used by the user if needed Again take extra care to make sure this header is standing perpendicular to the board when solder it down 17 Insert and solder the SPST power switch close to the top edge of the board There is no orientation for this component Once all of the components have been placed the bottom of the board should be visually inspected to en
24. g connector for mega8 AVR MICROCONTROLLER AVR MICROCONTROLLER RS232 TRANSCEIVER VOLTAGE REGULATOR NPN TRANSISTOR Camera Connector Power Connector Serial Connector Serial Connector JROBOT 26 JROBOT 9 Appendix B 9 1 Complete AVRcam Command Protocol The following tables list the various commands that can be used to control the camera and its capabilities Mnemonic Ping OpCode PG Payload lt none gt Response ACK if command successfully received NCK if command not successfully received Supplemental lt none gt Response Packet Example The user wants to ping the AVRcam to ensure it is responding User PG r AVRcam ACK r Mnemonic Change Camera Registers OpCode CR Payload RegAddr1 indicating the address of the first register to modify RegVal1 indicating the new value of the register specified in RegAddr1 lt space char gt RegAddr2 indicating the address of the second register to modify RegVal2 indicating the new value of the register specified in RegAddr2 lt space char gt RegAdadr8 indicating the address of the eighth register to modify RegVal8 indicating the new value of the register specified in RegAddr8 up to 8 registers may be modified with this format Response ACK if command successfully received NCK if command not successfully received Supplemental lt none gt The camera will begin using the new camera settings
25. hat the object is being tracked AVRcamView DAR File View Device Help Connect Disconnect Configure Serial Set Registers Ping Capture Disable Tracking fA Capture Frame 11 07 2004 10 24 28 System Messages racking Data racking Data File racking Data racking Data racking Data racking Data racking Data racking Data racking Data racking Data racking Data racking Data racking Data Red 60 Green 32 Blue 16 E Tracking File racking Data racking Data Start Recording racking Data SSSS racking Data racking Data racking Data racking Data racking Data racking Data racking Data The user can also view a real time stream of the communication between the AVRcam and the PC This can be viewed by selecting View gt Show Log from the main menu Ensure that the log level is set to Fine With this set all communication between the AVRcam and the PC will be displayed with a timestamp denoting when the message was sent This information is quite useful when testing out the system to understand how certain commands are formatted It should also be noted that this setup allows the user to view packets that are sent as binary values such as tracking and dump packets as well as those sent in ASCII such as basic commands The entire log file can be saved as either a text file or an XML file to be analyzed or parsed offline at a later time Note See Appendix B for a complete desc
26. m command consists of a simple two character ASCII operation code op code followed by optional ASCII parameters followed by a carriage return character The AVRcam JROBOT 16 JROBOT then responds with either a positive acknowledgement ACK indicating the command was successful or a negative acknowledgement NCK indicating that the command was not successful and should be re transmitted For example if the user wants to ping the AVRcam to ensure that the board is functioning properly the PING command can be sent to the board The AVRcam should then respond with a positive acknowledgement indicating that the board is functioning This example is illustrated below host system PG r AVRcam ACK r Here the host system is able to determine that the AVRcam is alive and operating properly because it responded with an positive acknowledgement Note The PING command has the op code PG For a complete list of op codes and their meaning see Appendix B Some command response pairs can also cause the AVRcam to provide a supplemental line of information in response to the received command For example the host system can request the software version of the AVRcam through the GET VERSION command GV The response to this command contains the normal acknowledgement immediately followed by the version information on the next line This example is illustrated below lt host system gt GV r AVRcam ACK r AVRcam AV
27. ming does fail simply power cycle the board If the yellow LED does not blink after a few seconds it is safe to attempt to re program the mega8 again If the LED does blink follow the programming guidelines stated above JROBOT 24 JROBOT 8 Appendix A 8 1 AVRcam Bill of Materials Part Description Quantity RS232 Level Shifter 1 AVR megas8 microcontroller AVR tiny12 microcontroller C3088 Camera Module LM2937 5V regulator Molex 2 pin connector male Molex 3 pin connector male 10 pin AVR ISP header SPST power switch 1K Ohm resistor 10K Ohm resistor 1 uF capacitor 0 1 uF capacitor 10 uF capacitor Green power LED Yellow signal LED 2N3904 NPN transistor 8 pin IC socket 14 pin IC socket 16 pin IC socket Dual row 32 hole female header AVRcam double sided circuit board DB 9 Female serial header 9 volt connector Molex 2 pin connector female Molex 3 pin connector female Crimp terminals for female conns Single pin male headers hort H a S AB as a a COP BROW KH AH PDS AH AK ASK a a JROBOT JROBOT 8 2 AVRcam Parts Cross Reference Part AVR_ISP C1 C2 C3 C4 C5 C7 C8 SWITCH T1 U 1 U 2 U 3 U 4 Value 057 010 1 0 1 uF 0 1 UF 0 1 UF 0 1 uF 10 uF 1 uF 1 uF 1 uF 1 uF MEGA8 P TINY12P MAX232 LM2937 JUMPER JUMPER GREEN LED YELLOW LED 10K 10K SPSTSWITCH 2N3904 OV6620 header MOLEX 2 CONN MOLEX 3 CONN MOLEX 3 CONN Description In System Programmin
28. on is represented When the mouse pointer is placed over the color of interest right click the mouse to add the color to the color map Add to Color Map Column Select Color Map Column 1 02 03 04 The color map supports up to 8 different tracked colors represented by one color per column in the color map In version 1 7 of the AVRcamVIEW a new Color Map window was implemented and is shown below JROBOT 20 JROBOT amp AVRcam VIEW Color Map kick 4 I l I 1 l I 1 I l 1 96 112 128 144 160 176 192 208 224 240 I 1 I 1 I 1 I 112 128 144 160 176 192 208 224 240 D 4 1 I 1 I LI 112 128 144 160 176 192 208 224 240 1 1 Auto Check Clear Indicies Clear All Reset Send This new Color Map allows the user to set the red green and blue ranges for each of eight tracked colors just as the previous Color Map in version 1 6 However instead of selecting from a series of check boxes to define the acceptable ranges for each color the user can simply move the sliders to define the minimum and maximum acceptable values for each color channel when defining a color to track Each color channel also displays the range of acceptable values as the sliders are moved around within the channel In the above example the second tracked color is being defined The acceptable red range is between 16 and 240 the acceptable green value is 16 and the acceptable blue range is between 208 and 24
29. on of 176 x 144 pixels e Low power consumption the entire system only draws 57 mA Small size the entire system is 2 4 x 1 9 JROBOT 5 JROBOT In addition a PC application called AVRcamVIEW was developed to support the AVRcam for purposes of evaluating and testing the system The AVRcamVIEW provides the following capabilities Take full color snapshots 176 x 144 pixels with the system and display the images both raw Bayer data and interpolated color data Easily create a Color Map of colors to track based on a snapshot just click on the colors of interest and add them to the Color Map Adjust the precision of each tracked color i e provide a range of acceptable R G B values for each color allowing the user to adjust the Color Map to the surrounding environment Display the real time tracking results of each tracked object with color and bounding box information Record a tracking session for playback at a later time Test the system out in multiple OS platforms that are supported by Java 1 5 both Windows and Linux are currently supported Finally one of the most important benefits to the AVRcam is that it is completely open source hardware software design docs everything In this regard the AVRcam should also be considered as a development platform for not only the existing capabilities provided by the system but new features that are tailored to the individual needs of a developer A set of core routines a
30. re provided in the source code that facilitate all of the low level interactions with the CMOS image sensor These routines can be utilized in a custom image processing application running on the AVRcam within the space speed capabilities of the system The existing AVRcam embedded software with all the features mentioned above occupies approximately 4K of the 8K on chip flash memory 700 bytes of the 1K on chip RAM and 48 bytes of the 512 bytes on chip EEPROM The system allows for complete in circuit re programmability of the image processing software using the standard 10 pin AVR ISP programmer All of the software on the AVRcam was developed using GCC an open source free C compiler that has been ported to the AVR family of microcontrollers meaning that the development environment for the AVRcam is completely free for any and all to use For more information see section 7 of this document Hopefully the AVRcam will open up many new possibilities to the developer for easily adding a vision system to your next project Please check http www jrobot net for discussions on the AVRcam as well as technical details and the latest source code JROBOT 6 4 JROBOT Building the AVRcam The AVRcam consists of several different components that should have been shipped with the system The list of components is listed below AVRcam bare circuit board Assortment of electronic components see Appendix A for a complete list of all component
31. ription of the different packet types and their payloads System Log SEVERE WARNING OINFO CONFIG FINE FINER FINEST C Show Only Level Message _ JROBOT 22 JROBOT Tracking can be disabled by left clicking on the Disable Tracking button in the Command Bar This will allow the user full access to the Command Bar again 6 6 How Lighting Affects the AVRCam It is important to note here that lighting conditions can have a significant impact on tracking capabilities For example objects that are highly reflective tend to appear as bright white spots in the presence of significant light regardless of color The best way to understand how lighting affects the AVRcam is to capture different snapshots in different lighting conditions to see how the images are seen by the camera It is also possible for the user to set parameters such as auto adjust mode auto white balance and flourescent light filtering by left clicking on the Set Registers button in the Command Bar Set Registers General Advanced Auto White Balance O Enable Disable Auto Adjust Mode 8 Enable Disable Flourescent Light Filter Enable Disable Cancel It should also be noted that different types of light will affect the AVRcam in different ways Specifically infrared light from incandescent lights or outdoor lighting can flood into the camera and cause the images to appear very red One way to de
32. s CD containing the AVRcamVIEW PC software as well as this User s Manual complete source code for both the AVRcam and AVRcamVIEW software and the WinAVR development environment containing the GCC C compiler and instructions for using it Power supply cable with connector to power the AVRcam Serial port cable with 9 pin D connector If the system was purchased already assembled and tested then the AVRcam circuit board will be populated with the assortment of electronic components already soldered and tested to be functional 4 1 Assembly Instructions for the Serial and Power Cables If the kit form of the AVRcam was purchased the serial and power cables have not been assembled yet The unassembled view of the cables can be seen below me en an y 4 1 1 Assembling the Power Cable 1 Connect the two metal crimp connectors to the end of the 9 volt battery clip This can be done with a standard crimper or a pair of needle nose pliers If desired a small amount of solder can be applied to hold the connection in place The result should look like the following picture JROBOT 7 JROBOT 2 Next insert the two crimped ends into the white Molex housing ensuring that the angled catch on the metal connectors locks into place in the Molex housing The power cable is now complete 4 1 2 Assembling the Serial Cable 1 Connect the female 9 pin serial connector to the 9 strand ribbon cable by feeding the ribbon c
33. s well as the Linux RPMs for the AVRcamVIEW PC application This installer will install the Java Runtime Environment JRE to the directory where the software is installed so that it will not cause a problem if other Java installations exist on the PC 5 1 Windows Installation Insert the CD into the PC and navigate to the Windows directory Double click on the setup exe file This will install the AVRcamVIEW application and place an shortcut on the Windows desktop The AVRcamVIEW application can then be launched by double clicking on this icon 5 2 Linux Installation It is necessary to install and run the AVRcamVIEW software with root privledges to allow for reading writing to the serial port under Linux So if not already done log in as root Next insert the CD into the PC and mount the CD ROM drive if not already mounted Change directories to the Linux directory on the CD and from a shell install the RPMs for the AVRcamVIEW software using the following command if a newer version of the AVRcamVIEW application is on the CD replace 01 03 with this name gt rpm i AVRcam 01 03 1 1586 This will automatically install the AVRcamVIEW application under opt AVRcam To launch the AVRcamVIEW application change directories to opt AVRcam and execute the following command jre bin java jar AVRcam jar JROBOT 15 JROBOT 6 Communicating with the AVRcam 6 1 Electrical Interface to the AVRcam The AVRcam provides its interface to an
34. shown below through the standard convention of a W character lt host system gt PG r lt AVRcam gt ACK Once this is successfully received request the software version of the system through the GET VERSION command lt host system gt GV r JROBOT 18 JROBOT AVRcam ACK r AVRcam AVRcam v1 0 r Congratulations You have now verified that the AVRcam is functioning properly and your serial connection is working properly Testing the AVRcam with a terminal emulator has its limitations since any command that causes the AVRcam to generate non ASCII i e non printable data will not be properly viewable on the PC The next step is to use the AVRcamVIEW software to further test the system But before this can be accomplished the terminal emulator running on the PC should be closed so that the serial port on the PC will be available for use by other programs 6 5 Testing the AVRcam with AVRcamVIEW The AVRcamVIEW PC application provides a simple way for the user to easily test out all of the features of the AVRcam Before the application can be used it must be installed on the host PC See Section 4 if the AVRcamVIEW software has not been installed yet If the AVRcam isn t already connected to the PC connect it using the serial cable and turn on the AVRcam Next start the AVRcamVIEW software on the host PC This will start the application displaying the main Command Bar as well as the Message Viewer and the Display Window
35. sure that all solder joints look clean and shiny The board should also be carefully inspected to ensure that no solder bridges have accidentally been formed connecting signals together that weren t meant to be connected If there are any questionable connection or solder bridges use a solder removal tool solder sucker solder wick to clean up the offending connection 4 4 Validating the AVRCam Assembly Once this inspection is complete use an ohmmeter to measure the resistance between the VCC and GND header pins near the left edge of the board to ensure that they are not shorted together Use the ohmmeter to carefully trace out each connection in the circuit if a short is found Plug in the header end of the AVRcam power cable to the 2 prong male Molex header near the top edge of the board Connect a suitable power supply such as a 9 volt battery or other voltage source between 7 and 20 Volts to the supply end of the AVRcam power cable JROBOT 14 JROBOT Switch the power switch on and the green LED should light up If it doesn t disconnect the power cable immediately and go back and re check all connections on the board If it the green LED does light up use a voltmeter to measure the voltage between the VCC and GND headers near the left edge of the board The voltage should be close to 5 Volts If not disconnect the power cable immediately and go back and re check all connections on the board Once the proper voltage is measur
36. x32 0x39 0x76 0x98 0x0F Note The AVRcam is capable of tracking up to eight color blobs values 1 through 8 as defined by the current color map per frame This number is variable and may also be zero All currently tracked blobs wi Il be returned inside of each color tracking packet Mnemonic Disable color blob tracking OpCode DT Payload lt none gt Response ACK if command successfully received NCK if command not successfully received Supplemental Response Packet lt none gt Color blob tracking will end Example The user wants to disable color blob tracking User DT r AVRcam ACK r JROBOT 29 JROBOT Mnemonic Set the Color Map OpCode SM Payload red0 red1 red2 red15 green0 green1 green15 blue0 blue1 blue15 gt r Response ACK if command successfully received NCK if command not successfully received Supplemental none The AVRcam will update its color map Tracking should be Response DISABLED before setting the color map and re enabled afterwards to begin a Packet new tracking session Example The user wishes to update the color map used to turn RGB YCrCb values into actual colors User SM 98 183 32 124 234 64 94 167 129 201 229 74 r f ea ola dle a blue15 blue14 fi thy 4 blue13 red8 red4 red3 red2 AVRcam ACK r JROBOT 30 1
37. ypically The complete formatting for each user interface command response can be found in Appendix B This section also contains the complete formatting for the supplemental information packets that are sent by the AVRcam according to the mode of the AVRcam JROBOT 17 JROBOT 6 3 AVRcam Modes The AVRcam can be put into three different modes Each mode allows for different functionality in the system 6 3 1 Idle Mode The first mode is the Idle Mode This is the default mode of the AVRcam In this mode the system is not sending any additional information packets back to the host system 6 3 2 Frame Dump Mode The second mode is the Frame Dump Mode This mode is entered by sending the DUMP FRAME DF command to the AVRcam This command causes the AVRcam to start sending frame dump packets back to the host system until an entire image frame has been sent This mode is only temporary while the frame dump packets are being sent Once all frame dump packets for a complete frame have been sent the AVRcam transitions back to the Idle Mode 6 3 3 Color Tracking Mode The third mode is the Color Tracking Mode This mode is entered by sending the ENABLE TRACKING ET command to the AVRcam This command causes the AVRcam to start sending tracking packets back to the host system These tracking packets will continue to be sent as long as the system is in the Color Tracking Mode If no trackable objects are found in the image stre
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