User Guide
Contents
1. Tracking Mode Detail color E 11 19 2007 4 07 05 o bject v mindsensors com 4 12 In line tracking mode beginning point and end point coordinates of a line representing the object are returned In the following picture the bounding boxes are drawn for the line coordinates received from NXTcam Fe ven Tee Wnion Hep PBB connect Pa Capture Ail Disconnect 95 E Tra Tracking e E r 194 g 170 b 129 CON raking info mo CD for the lines g ho olor tolerance 4 N ID NXTCapture144025 Colors in range 100 PP Hide Tracking Running Tracking Statistics Uploaded Colors Total 70580 Frame count 15309 No Color Total Filtered Filtered In 70580 Avg frame 4 1 TR 1632s 16328 Filtered Out 0 area filter 0 4 More about Colormaps The objects of interest are recognized by NXTCam by matching the stored color values with the captured image To do that color values of the objects of interest need to be stored on NXTCam These color values are known as Colormaps NXTCam can store up to 8 Colormaps and provide processed information of the objects matching those Colormaps For more information on how to pick Colormap values of your objects of interest and how to store them on NXTCam using the NXTCamView software please refer to section teaching NXTCam colors from URL http nxtcamview sourceforge net Also watch a demo video Capture and Select at following URL http nxtca2. tab and select the Device Manager Expand the Universal Serial Bus Controller entry You should see NXTCam listed In the same Device Manager Expand Ports COM amp LPT entry You should see a COM port listed for NXTCam this is the COM port you should use for your viewer software configuration a os SS To ensure actual USB communication follow these steps 1 Connect the NXTcam using a USB cable to your computer 2 Run Hyperterminal Start gt All Programs gt Accessories gt Communication gt Hyper Terminal 3 Give a name for the configuration say mynxtcam In the next dialog box specify Connect Using lt NXTCam COM Port gt the port you noted from Ports Com and LPT entry in Device Manager Click OK In next window Specify Bits per second 115200 Data bits 8 Parity None Stop bits 1 Flow Control None Click OK 8 In the main terminal window just press lt enter gt You should get a response from NXTCam as NCK 9 In the same window type GV lt enter gt You should get a response from NXTCam as NXTcam V n n where n n is your NXTcam version number Troubleshooting NXTCam communication with your NXT Ensure to install NXT G blocks for NXTCam as mentioned above in the document mindsensors com 7 12 Connect your NXT to your PC using it s standard USB cable Connect your NXTCam to NXT Port 1 using standard NXT sensor cable Run NXT G software on your computer Pow
3. Camera register Address Ox7B 8 Camera register Data 8 Camera register Data 0x80 Color map data Red O Color map data Red O 0x80 OxAF These registers are used for Colormap data reading and writing 0x80 Color map data Red O Color map data Red O 0x81 Color map data Red 1 Color map data Red 1 0x82 Color map data Red 2 Color map data Red 2 Write 0x01 to register Ox6B Write 0x00 to register Ox6C Run command H Results will be stored in register Ox6D 3 If you need to read image sensor register 0x00 i e 1 register then follow this If you need to write to image sensor register 0x00 i e 1 register then follow this Write 0x01 to register Ox6B Write 0x00 to register Ox6C Write data to register Ox6D Run command C Run command G Read registers 0x80 OxAF If you need to write Colormap data to camera engine then follow this If you need to read Colormap data from camera engine then follow this Write your color map data in registers 0x80 OxAF Run command S mindsensors com 11 12 Register Read Write Comments 0x83 Color map data Red 3 Color map data Red 3 0x84 Color map data Red 4 Color map data Red 4 0x85 Color map data Red 5 Color map data Red 5 0x86 Color map data Red 6 Color map data Red 6 0x87 Color map data Red 7 Color map data Red 7 Color map
4. am capture that picture for analysis and configure the Colormaps for onboard processing you will need to install and use Viewer and Configuration software on your PC For MS Windows XP Vista download Viewer and Configuration software from http nxtcamview sourceforge net For Macintosh download Viewer and Configuration software from http www mindsensors com index php module documents amp JAS DocumentManager_op viewDocument amp JAS Document id 53 Programming Environment s NXTCam is supported for use in NXT G using a custom block Download the block from following URL http www mindsensors com NXTCam_ NXT G_ Block htm This block provides functionality for tracking objects based on the Colormaps downloaded on NXTCam Follow the installation instructions provided at this URL to install the block Note While using with NXT G ensure to use firmware version 1 05 LeJOS API s are available at http lejos sourceforge net p_ technologies nxt nx j api leios nxt NXTCam html RobotC API s are available at http www mindsensors com index php module documents amp JAS DocumentManager_op viewDocument amp JAS Document id 50 mindsensors com 2 12 NXC NBC Library functions are available at http www mindsensors com index php module documents amp JAS DocumentManager_op viewDocument amp JAS Document id 57 Connecting NXTCam Wiring for NXTCam NXTCam may be connected to any of the sensor ports of NXT using stand
5. ard NXT connector cable In your program select the appropriate port number to which NXTCam is connected Ah WARNING Do not connect the NXTCam to any motor port as the voltage applied by the motor port may damage the electronics of NXTCam During offline operations such as programming and configuration NXTCam must be connected to PC using USB cable as well as NXT using standard NXT connector cable while NXT is powered ON During runtime or autonomous operations on NXT the USB connection to PC must be removed NOTE While NXTCam is connected to NXT as well as PC the PC communication takes priority over any other communication In other words while NXTCam is connected to PC as well as NXT if you run a program on NXT it will not be able to talk to NXTCam Mounting NXTCam on your contraption The holes on the NXTCam enclosure are designed for tight fit of Technic pins or axles with cross section The holes however are not designed for repeated insertions removals of these pins To mount NXTCam v2 on your contraption we suggest that you use two dark gray Technic Axle 3 with Stud as shown Insert axles from the front lens side of the NXTCam and secure with a bushing on the back or mount it on your contraption directly NXTCam y2 Alternately you may use blue Technic Axle Pin with Friction as shown e While disassembling contraption leave the axles and or pins on NXTCam mind
6. bject color This is the first object color as per the sorting method selected 0x44 1 object X upper left Upper left X coordinate of first object 0x45 1 object Y upper left Upper left Y coordinate of first object 0x46 1 object X lower right Lower right X coordinate of first object 0x47 1 object Y lower right Lower right Y coordinate of first object 0x48 2 object color 0x49 0x4C 2 object co ordinates Ox4D 3 object color Ox4E 0x51 3 object co ordinates 0x52 4 object color 0x53 0x56 4 object co ordinates 0x57 5 object color 0x58 0x5B 5 object co ordinates Ox5C 6 object color Ox5D 0x60 6 object co ordinates This repeats for all 8 objects Please note that object position and coordinate are overwritten if new object is detected otherwise previous value is retained mindsensors com 10 12 Register Read Write Comments Ox61 7 object color 0x62 0x65 7 object co ordinates 0x66 8 object color 0x67 O0x64 8 object co ordinates Ox6B No of registers to Read No of registers to Write This is the number of registers you need to read or write from camera image sensor Ox6C 1 Camera register Address 1 Camera register Address Ox6D 1 Camera register Data 1 Camera register Data 1 register Data read from image sensor or written to image sensor Ox7A 8 Camera register Address 8
7. data Red 15 Color map data Red 15 Color map data Green O Color map data Green O Color map data Green 1 Color map data Green 1 Color map data Green 15 Color map data Green 15 Color map data Blue O Color map data Blue O Color map data Blue 1 Color map data Blue 1 Color map data Blue 15 Color map data Blue 15 mindsensors com 12 12
8. er on the NXT Start a New Program say Untitled 1 and from Advanced Block Palette drag and drop the NXTCam block in it 6 Click on the block and examine the bottom left corner of NXT G window where block control pp panel is located go SE wn E Port G1 02 Da Da 7 You should see NXTCam version AF Address Ox 2 number shown in the ae Fi Mod Disable Tracking bottom left corner as shown in the adjacent picture 8 If the NXTCam is not connected correctly to your NXT this status will indicate No Device If that happens ensure the port and Address in your program match to what s on NXTCam mindsensars com Reference Information Wiki for NXTCamView NXTcam and related Projects and findings Visit following URL for the wiki http nxtcamview wiki sourceforge net Open Source Software and Hardware NXTCam is based on AVRcam and is Open Source using GNU license We encourage you to improve the source code and features and inform us the changes for inclusion in future releases Visit following URL to download the source code and related docs http www mindsensors com NXTCam_ Source Code htm I2C Operations Pins used SDA 1 GND 2 SCL 3 5V 4 Following table lists the register definitions and setup commands Commands ee ASCII Hex A 0x41 Sort tracked objects by size B 0x42 Select Object tracking mode C 0x43 Write to Camera Registers FA Use extreme CAUTION when
9. his means that NXTCam can coexist with LEGO or third party digital sensor on the same NXT port ADPA support enables user to employ several sensors on the same port without the need of external sensor multiplexer reducing the overall size without compromising the functionality What you will need before using NXTCam Connector Cables For runtime operations on the robot in autonomous mode the NXTCam connects to NXT ona sensor port using a standard connector cable that comes with NXT the one with jacks similar to phone jacks mindsensors com 1 12 For offline operations for programming and configurations NXTCam connects to PC using mini USB cable This is in addition to the cable you would use to connect NXT to your PC Adjacent picture shows the mini USB connector you would need on your USB cable this connector is commonly used for digital cameras If you need to acquire a cable separately it should be a 5 wire cable USB Driver installation In order for NXTCam to work properly you will need to install USB drivers for your operating system Currently support exists for Windows XP i386 and AMD processors Windows Vista i386 and AMD processors Mac OS X v10 4 10 PowerPC 64 Download the drivers and installation instructions from following location http www mindsensors com NXTCam_ Driver Installation htm Viewer and Configuration Software To see the picture that s in the field of view of NXTC
10. ing your Colormap Human eye and brain is conditioned to adapt to ambient light conditions and see Whereas based on ambient light the colors of objects appear different to a camera CCD In other words a blue ball in your laboratory lighting conditions will appear to be a different shade of blue than in Gymnasium lighting Considering this aspect ensure to update your NXTCam Colormap based on your final lighting conditions Changing the I2C Bus Address The factory default I2C address of NXTCam is 0x02 This address can be changed To set an address different from default address send sequence of following commands on the command register OxAO OxAA OxA5 lt new I2C address gt Note Send these commands with no break read operation in between This new address is effective immediately Please note down your new address carefully for future reference Alternately you can download address scan and change functions written in RobotC from following URL and change them to suit your needs http www mindsensors com RobotC Utility Programs htm mindsensors com 6 12 Troubleshooting NXTCam communication Troubleshooting NXTCam communication with your PC To ensure USB drivers are installed properly follow these steps 1 Ensure to install the USB drivers as mentioned in this document 2 Connect the NXTcam using a USB cable to your computer 3 From Start menu gt Right click on Computer select Properties select Hardware
11. mindsensors com NXTCam v2 User Guide What is NXTCam NXTCam is a real time image processing engine Think of it as a vision sub system with on board processor and a protocol interface that is accessible through a standard NXT sensor port This interface provides high level post processed information of the image NXTCam sees The processed information contains the bounding box coordinates of the objects of interest in view of NXTCam in line tracking mode this information contains coordinates of line segments NXTCam does not send the image itself to NXT however connecting NXTCam to a PC with USB cable and using a Viewer and Configuration software you can see the image on the PC NXTCam Feature List The NXTCam provides following capabilities e Track up to 8 different colorful objects at 30 frames second e Configure the NXTCam using USB interface on Windows XP Windows Vista e Supports two tracking modes Object tracking and Line tracking e Provide real time tracked object statistics number of objects color of objects bounding box coordinates or line coordinates through a standard NXT sensor port e Tracked image resolution of 88 x 144 pixels at 30 frames second e Perform full resolution 176 x 144 pixels color image dumps to PC via USB port e Maximum power consumption 42 mA at 4 7 V e Uses NXT compatible I2C protocol for communications e Supports Auto Detecting Parallel Architecture ADPA for NXT sensor bus T
12. mview sourceforge net DemoScreenCam htm Tips on using NXTCam in your environment Object Colors in Line Tracking Vs Object Tracking Modes In the object tracking mode you can track objects comprising of 8 distinct colors While selecting colors avoid any overlap between colors of different objects In line tracking mode only the first color from the Colormap is used and it is recommended to limit the number of colors to one mindsensors com 5 12 Lighting conditions The NXTCam is designed to operate under white fluorescent light If you notice reddish image color which tends to happen when your environment has lot of ambient Infrared light try to find the source of Infrared light and reduce it by replacing it with fluorescent light For advanced operations it is possible to change color gain brightness and contrast of NXTCam by manipulating the I2C register values Focus As a factory default NXTCam lens is set for optimal focus between 2 and 4 feet The lens is screwed in it s holder and it is designed to be tight to prevent accidental rotation and loss of focus To refocus the lens gently turn the lens from the holder capture images and see if the new focus is satisfactory Do not apply excessive force as it may damage the lens For better grip while turning lens you may wrap a rubber band around the exposed threads of the lens To check the focus you can use Viewer software and performa capture and see the results Updat
13. sensors com 3 12 LED on NXTCam The LED on NXTCam lights up whenever NXTCam is supplied with power Under normal operations the power will be supplied by NXT from the sensor port Configuring Colormaps in NXTCam Default Object Colormap The NXTCam is shipped with a default Colormap to track a light source Download a test program or write a test programs and try tracking a light source Objects of interest Below are screen dumps of NXTCamView software showing objects of interests and their tracking information The top left window in the picture below shows the field of view of NXTCam The objects of interest from this view are the red and blue pens In the object tracking mode the bounding box coordinates are returned as shown File View Tools ow Help d VIE Lil Dalai 7 aa ti NE H I Connecti Capture Disconnect 2 Tracki W NXTCapture160751 Tracking information for the Objects of Interest X 148 Y 107 E ol ig a AR RELA 0 EL Gal ZE IEI g 249 Hide Tracking Stopped Pause Color tolerance Tracking Statistics Uploaded Colors Options Tatal 14786 Frame count 4208 No Color Total Filtered Colors in range 200 i Connection NXTCam Advanced General Ride Beg ia tag edule 2 1 E 2759 2759 Filtered Out 0 Area filter 0 s 2 3904 3964 p Use AutoWhiteBalance mode Blob Details CI Use AutoAdjust mode Color Solid _ Color Na Use flourescent light filter Pepe Size ATE
14. using command C since this can stop your camera working properly In case this happens please power off your NXTCam mindsensors com 8 12 and power it on again D 0x44 Disable Tracking E 0x45 Enable Tracking G 0x47 Get the Color map from Camera Engine H 0x48 Read data from the Camera Registers I 0x49 Illumination on Future L 0x4C Select Line tracking mode N Ox4E Set ADPA mode ON setting stored in NVRAM O Ox4F Set ADPA mode Off default setting stored in NVRAM P 0x50 Ping camera Engine R 0x52 Reset Camera Engine S 0x53 Send the color map to camera Engine T 0x54 Illumination Off U 0x55 Sort tracked objects by color V 0x56 Get camera Engine firmware version No Read resulting string at 0x42 12 bytes X 0x58 Do not Sort tracked objects mindsensors com 9 12 In case of line tracking mode these are coordinates of beginning and end points of the line I2C Registers The NXTCam appears as a set of few registers as follows Register Read Write Comments 0x00 0x07 Software version Vn nn 0x08 0x0f Vendor Id mndsnsrs 0x10 0x17 Device ID NXTCam 0x41 Command This register is command register A command written here will be executed 0x42 Number of objects detected Shows how many objects are being tracked Zero indicates that there are no objects being tracked 0x43 1 o
Download Pdf Manuals
Related Search