User`s Manual v1.0
Contents
1. Figure 1 AVRcam circuit board layout JROBOT 6 JROBOT 3 2 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 itch DC in e i Top Edge did dx TTL level SIGI Serial LED Connector Power RS232 TTL LED selector jumper JP2 Test Points GND 14 doe 42 ee SIGI ICE XTYEREIEU 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 7 Mounting Holes JROBOT 32 pin Camera Connector C3088 Camera Module with OV6620 Photo 3 FRONT side of assembled AVRcam with camera detached AVRcam should be assembled in the following order 1 2 3 Insert and solder R1 R2 R4 R5 R6 R7 R8 and R9 Insert and solder C12. 7 JROBOT GND 25
3. red4 red3 red2 AVRcam JROBOT 24 JROBOT 9 Appendix C v1 1 Schematic Pg 0 1 uF 232 GND R4 RON R20UT RIN RIOUT T20UT T2N A TOT 057 010 1 AVR ISP AVR_ISP 2 cz 5181 AVRISP B m AVR ISP 9 AVRISP5 4 9e AVR ISP AVR 5 AVR ISP 8 AVR_ISP 2 4 AVR ISP 10 GND ND o amp Ed R8 l GND 10K 5192 Ht MOUNT PAD ROUND3 2 H2 2 PD1 TXD MOUNT PAD ROUND3 2 vec PDQIINTA PCL PD3INTI gt H3 VSYNC PDA XChNITO on HREF PDS T1 5 MOUNT PAD ROUND3 2 L EB LAO i L uva PD7JAN1 Uva vec Qoni ikoa mov An uv uva GND tok PE1iOC1A 10K PE2iSS OC1E PB3 MOSIOC2 PB7 XTALITOSC2 PE4iMSO vo PESISCh PBSDXTALITOSCH YA Y2 PCO ADCA Y3 1 1 AGND 1 Y4 PC2 ADC2 AREF o9 x AGND2 AGND 255 AGND_3 PCA ADCAISDA GND Y PCS ADCS SCL PCA RESET 1 2 5 4 NEGARE x e g 5 S ALPES GND n ISCh PE2 2N3904 215 vce 5 1 E 4 2 5 E GND MOs PEU oot END
4. Mnemonic Enable color blob tracking OpCode ET Payload lt none gt Response ACK if command successfully received if command not successfully received Supplemental Response Packets 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 Byte 0 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 AVRcam AV Rcam 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 Indi
5. C4 C6 and C10 None of these capacitors are polarized so their orientation is not critical 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 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 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 IC2 Solder it down ensuring that the notch on the socket is properly oriented pointing to the bottom edge of the board 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 Insert and solder IC5 to the board Make sure that the front of this chip where it says 11 2937 is facing the top edge of the circuit board JROBOT 8 JROBOT 8 Insert and solder the AVR_ISP programming header Make sure that the center
6. 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 5 2 Protocol Overview A typical AVRcam 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 then responds with either a positive acknowledgement ACK indicating the command was JROBOT 11 JROBOT successful or a negative acknowledgement 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 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
7. notch in the header is not facing the 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 of 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 it should be inserted in the hole closest to the bottom edge of the circuit board 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 so
8. packets are being sent Once all frame dump packets for a complete frame have been sent the AVRcam transitions back to the Idle Mode 5 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 stream 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 5 4 Testing the AVRcam User Interface 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 te
9. EW 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 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 The first step with the AVRcamVIEW software is to ensure that the proper serial port has been selected on the PC From the main menu bar select CHECK and ensure that the serial port connected to the is the one selected by the serial configuration window CHECK name Once this is completed close the window and return to the main Display Window It is now time to send a 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 either or 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 Capture Enable Tracking Connect Disconnect Configure Serial Set Registers JROBOT 14 JROBOT
10. JROBOT AVRcam User s Manual Version 1 0 JROBOT JROBOT Table Of Contents 1 Copyright Licensing Disclaimer 220 3 2 EELT E ATS EIO E Ade db ua A 4 9 Bolding the V INCA e 6 3 1 Assembly 6 3 2 Before 7 3 3 Validating the AVRCam 9 4 Installing the AVRcamVIEW PC Software 10 4 1 Windows Installations 05 Spe haste 10 42 eds 10 5 Communicating with the 0 222 2 2 11 5 1 Electrical Interface A V ROAM 11 23 2 Protoc l Overview he ae BA 11 5 3 AVR Cami Mode S cniin bieten Deed 13 5 3 1 idle Modernisieren 13 5 3 2 Frame Dump 13 5 3 3 Color Tracking Modes 13 5 4 Testing the AV Ream User Interfaee sit ee ete miens rac npe 13 5 5 Testing the AVRcam with 1 14 6 Advanced Development with the 19 d sex he e 20 83 Nppelidbe Bikes sat o eo athe 21 8 1 Complete AVRcam Command 21 Append y 25 JROBOT 2 JROBOT 1 Copyright Li
11. 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 AVRcamView File View Device Help Connect Disconnect Configure Serial Set Registers ping Capture Enable Tracking 11 07 2004 10 24 28 Red 240 Green 16 Blue 16 Frame Data 71 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 combination 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 9 Select Color Map Column 4 02 03 04 05 The color map supports up to 8 different tracked colors represented by one color per column the color map Each tracked color is made up of a red component a green component and a blue component Thus for the tracked color a single check box
12. 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 26v 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 21 JROBOT Mnemonic Dump a Frame OpCode DF Payload lt none gt Response ACK if command successfully received if command not successfully received Supplemental Raw color frame dump packets Response Byte 0 OxOB indicating the start of raw color data line Packet Byte 1 line number in hex indicating which line number is being sent Each pixel stack consists of a one byte value where the high nibble represents one color value either red or green and the low nibble represents one color value either green or blue The pixels on the camera are arranged in Bayer format Even pixel high nibbles green value Even pixel low nibbles red value Odd pixel high nibbles green value Odd pixel low nibbles blue value Byte 2 178 176 hex pixel stacks where a pixel stack is structured as follows 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 com
13. RONT 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 once and then stay powered up 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 4 Installing the AVRcamVIEW PC Software The enclosed CD contains the both the Windows installer as 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 41 Windows Installation Insert the CD into the PC and 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 4 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 alread
14. Set Registers button in the Command Bar Set Registers General Advanced Auto White Balance Enable Disable Auto Adjust Mode Enable Disable Flourescent Light Filter Enable Disable Cancel JROBOT 18 JROBOT 6 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 mega 8 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 GCC a port of the standard GCC C compiler to the AVR fami
15. ard Connect a suitable power supply such as a 9 volt battery or other voltage source between 7 and 20 Volts CHECK to the supply end of the AVRcam power cable 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 measured between VCC and GND disconnect the power from the circuit by turning the power switch off Then insert 1 2 and IC3 into their appropriate JROBOT 9 JROBOT 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 F
16. cates start of color tracking packet AM Rcam 0x0A 0x05 0x06 0x32 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 be returned inside of each color tracking packet Mnemonic Disable color blob tracking OpCode DT Payload none Response ACK if command successfully received if command not successfully received Supplemental Response Packet none Color blob tracking will end Example The user wants to disable color blob tracking User DT r AVRcam JROBOT 23 JROBOT Mnemonic Set the Color Map OpCode SM Payload lt red0 red1 red2 red15 0 green1 green15 blueO blue1 blue15 gt r Response 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 b ew se out d blue15 blue14 blue13 red8
17. censing Disclaimer Info AVRcam Hardware and Embedded Software Copyright 2004 John Orlando AVRcamVIEW PC Software Copyright 2004 Brent Taylor 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 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 JROBOT 3 JROBOT 2 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 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 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 le
18. 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 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 description of the different packet types and their payloads System Log SEVERE WARNING INFO CONFIG FINE FINER FINEST C Show Only Level Message 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 JROBOT 17 JROBOT 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
19. has been filled in each column This sets the acceptable red green blue pixel values that will be considered tracked for the color This map can be manually expanded to decrease the precision with which the color is tracked by simply checking a few of the surrounding boxes in each column This will allow for some variance in the sampled pixels while still considering the pixels to be tracked JROBOT 15 JROBOT System Colors 20 FE CE REET G AutoCheck Clear Column s Clear All Reset Send Color Map System Colors 2 200 EE EET Coe er Coe Zo Pe ee T Auto Check Clear Columns Clear All Reset Send Next send the color map down to the AVRcam by left clicking on the Send button in the Color Map window The Message Viewer display should show an ACK was received after the color map was sent and the newly tracked color is displayed at the top of the Color Map window Close the Color Map window to return to the main window Now that the color map has been set left click on the Enable Tracking button in the Command Bar This will start the camera t
20. ldering 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 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 ensure 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 3 3 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 bo
21. ly 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 www 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 www jrobot net Forums JROBOT 19 JROBOT 7 Appendix A AVRcam Bill of Materials Part Description Quantity RS232 Level Shifter 1 AVR 8 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 double sided circuit b
22. mand is received Example The user wants a single frame of image data sent to them actual RGB values User DF AVRcam 0x0B 0x01 0x83 OxD3 0x4A 173 more pixels 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 0x0B 0x02 0x83 0xD4 0x3A lt 173 more pixels gt 0x0F AVRcam 0x0B 0x48 0x83 OxD4 0x3A 173 more gt 0 0 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 none Response ACK if command successfully received NCK if command not successfully received Supplemental Response Packet The camera will send a string indicating the software version number Example The user wants to determine what version of software is running on their AVRcam User GV r AVRcam AVRcam AVRcam v1 0 r JROBOT 22 JROBOT
23. oard 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 Rho t SH S S ASH ASB S RO WO HH KD AH AH HK AB JROBOT JROBOT 8 Appendix B 81 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 none Response Packet Example The user wants to ping the AVRcam to ensure it is responding User PG AVRcam ACK r Mnemonic Change Camera Registers RegAddr1 indicating the address of the first register to modify RegVal1 indicating the new value of the register specified RegAddr1 space char RegAddr2 indicating the address of the second register to modify RegVal2 indicating the new value of the register specified in RegAddr2 space char 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 if command not successfully received Supplemental none The camera will begin using the new camera settings Response
24. 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 host system GV lt AVRcam gt ACK r lt AVRcam gt AVRcam 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 AVHRcam formatted tracking packet containing hex characters AVHRcam formatted tracking packet containing hex characters AVHRcam formatted tracking packet containing hex characters The above example shows how the ACK from the AVRcam is follo
25. 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 6 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 3 JROBOT 3 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 components CD containing the AVRcamVIEW PC software as well as this User s Manual and the complete source code for both the AVRcam and AVRcamVIEW software 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 3 1 Assembly Instructions 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
26. racking any color that has been programmed into the Color Map Note The Command Bar has certain operations disabled while the system has tracking enabled JROBOT 16 JROBOT 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 that the object is being tracked AVRcamView File View Device Help Connect Disconnect 16 onfigure Serial Set ers Ping Capture Disable Tracking racking Data v Capture Frame 11 07 2004 10 24 28 u m bi 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 racking Data racking Data racking Data racking Data racking Data racking Data Start Recording racking Data racking Data racking Data racking Data racking Data 1 racking Data racking Data racking Data System Messages 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
27. rminal 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 shown below through the standard convention of 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 13 JROBOT lt AVRcam gt ACK r lt AVRcam gt 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 5 5 Testing the AVRcam with AVRcamVI
28. rovide 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 e 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 are 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 AV Rcam 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
29. vel 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 resolution of 176 x 144 pixels Low power consumption the entire system only draws 57 mA Small size the entire system is 2 4 x 1 9 JROBOT 4 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 p
30. wed 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 ASCII 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 typically 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 12 JROBOT 5 3 AVRcam Modes The AVRcam be put into three different modes Each mode allows for different functionality in the system 5 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 5 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
31. y mounted Change directories to the CD and from a shell install the RPMs for the AVRcamVIEW software using the following command gt rpm AVRcam 01 03 1 586 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 AVRcam jar JROBOT 10 JROBOT 5 Communicating with the AVRcam 5 11 Electrical Interface to the AVRcam The AVRcam provides its interface to an 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 a TTL Port Rx connect to Tx on external controller Tx connect to Rx on external controller Gnd RS232 Port Gnd 4 Tx connect to Rx on PC io rc A DE 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
Download Pdf Manuals
Related Search