voelker

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  1. voelker

    Papilio + ov7670 camera = spartcam !

    Hi, i managed to get a harris coner detector to run on the papilio using the same setup (ov7725 + papilio + fx2 usb fifo). In this video the camera films a chessboard and output the positives harris values (score based on corner detection). The design takes 8 BRAMs (1 for sobel, 6 for harris, 1 holds camera configuration) , 5 multipliers and 37% of slices. It runs on the papilio 250k.
  2. voelker

    Papilio + ov7670 camera = spartcam !

    Hi, sorry for the delay. I'am feeding the cmaera module with 24Mhz and the frame rate is 30fps with my settings (checked with logic analyzer). How did you check the framerate ? The YUV format outputs as YUYV each component being coded on 8 bits. QVGA and VGA works for me. You may try to have a look at your I2C communication, i found the OV7670 to act weird sometime with the i2c communication. After a period of inactivity i have started on working on the interface between the papilio and the FXLP USB2.0 component to be able to display the images a full-framerate full-resolution on a PC (ft2232 of the papilio only allowed 80*60 @ 30fps). I succeeded and i now can watch my camera output in 320*240 @ 30fps with a custom application using libusb. The next step is to transmit the VGA frame at 30fps (4 times the bandwidth). The FX2LP is a really nice and cheap component (dev board @ 10€ on ebay) that should allow to get 40MB/s with a custom driver (libusb executes in user-space). I'll post pictures ASAP.
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  4. voelker

    Beagle playing with papilio

    i tried the bus into signal and control, and it improved significantly the noise i get on CS and RD. Next step is to shield these signal and carry multiple ground to prevent cross-talk. I also made a fix in the HDL that would prevent glitch on the signals using a RS lock and a counter. Using these two fix i can now grab a frame through the papilio with the beaglebone, and compress it to jpeg. I now get around 9MByte/s bandwidth while reading and 18 MByte/s when writing but i hope to double reading speed by working on timings. I now have my papilio + custom camera shield stacked with the beaglebone in a 8cm*8cm*8cm brick. This hold quite a lot of processing power (720Mh arm Cortex A + Spartan 3E) and should be able to run high level vision tasks (SLAM anyone ?). The goal is to design a cape for the beaglebone with a spartan 6 and a camera connector. A custom cape should allow to get rid of noise, and speed-up communication (max theoretical is 200 MByte/s).
  5. voelker

    Beagle playing with papilio

    After playing with the oscilloscope and the logic analyzer we found multiple cause of failure. When transmitting data a voltage drop appears between the two GND (bgealbone and papilio), we tried connecting more GND pins and it only reduced the drop amplitude but the problem remains. When transmitting data the power supply of the papilio is versy noisy (spikes up to 200mv). Maybe adding 22µF capacitor on the 3.3v rail may help. I might also try to shiled my cable using copper tape.
  6. voelker

    Beagle playing with papilio

    It seems that Alex is right. When switching the databus, there is a noise of ~300mv on the power supply (see picture). If anyone has a solution to this kind of problem, i'd be glad to hear it.
  7. voelker

    Beagle playing with papilio

    i'll check on that. But why would this happen only on one transfer and not on the others ?
  8. voelker

    Beagle playing with papilio

    Hi, the spartcam projet i did (papilio + ov7670) project i am working on is working nice and i'am looking to extend the processing power of the platform to run more advanced vision algorithm. Having beaglebone (http://beagleboard.org/) i thought it would be nice to get the papilio and beaglebone communicate together. The beaglebone has a GPMC interface so i started working to interface with. So far i got the two to communicate together, i wrote a kernel driver and slave memory interface for the papilio. Transfer rate are still a bit low (21MByte/s writing, 14 MByte/s reading) but i hope to bring some improvement on that point (i target ~40Mbyte/s). To get the logic inside the papilio interface with the beaglebone i designed bi-directionnal fifos for fast synchronisation free communications. I still struggled to get this working properly. The fifo works, and the interface with the beaglebone works, but i have a bug in the communication that makes the fifo lose one token (16 bit word) for a burst of communication. I observed the communication and there is a glitch on the read, cs signals of the beaglebone only fo the second word access. All following accesses of the burst looks nice. This glitch occurs randomly but is always present when the data to transfer has most bits to high. I first thought of interference between the lines, but it does not explain why it happens only on second read of the transfer. If anyone has an idea of what is going on, or a solution, i would be glad to hear it.
  9. voelker

    Multi Color Object Tracking with Papilio and TCM8230

    Hi, very nice work ! Can you give detail on tracking framerate (30hz ?) , resolution and memory utilization of the papilio one ?
  10. voelker

    Papilio + ov7670 camera = spartcam !

    another video example of papilio running a canny edge detector and displaying result on LCD :
  11. voelker

    Papilio + ov7670 camera = spartcam !

    Hi, i got a 2.4" LCD running with my custom board to display image from the camera and have a live full-resolution view of the processed image. The image is updated in LCD memory at 30hz but it seems that the refresh rate of the LCD is slightly lower resulting in some artifact for fast moving objects. I use the YUV output of the camera that i then convert to RGB using some custom messy HDL code. video below This post has been promoted to an article
  12. if you want to read the whole thing please check the original project thread here
  13. voelker

    Bare Bones I2C Master Writer

    Hi, very nice, your VHDL coding style is much better than mine ... I see that you plan to use (or are using) a TCM8230 camera module and a video encoder, what is your project goal ?
  14. voelker

    Papilio + ov7670 camera = spartcam !

    i finally received my PCB from seeed studio, ordered 10 but got 12 ! Whil waiting for the PCB i identified one schematic error (a decoupling capacitor on the regulator wired to the adj pin instead of gnd ...), and some design mistakes. The most important design mistake is that the port i wired for LCD control provides 3.3v supply while most lcd will take 5v. Its not a big mistake but i will include a jumper in furture to select between 5v and 3.3v. Another flaw is that when using the ov7670 the sensor is not centered on the board. This is not a big problem since i plan to use the OV7725 but i will move the connector location. I soldered one board and modified the UCF file and everything worked on first try. I still need to test communication with the I2C eeprom, fifo port and LCD port. On the HDL side, i have done some refactoring to get less warning on synthesis. There is still a lot of work to do (implement LCD interface, and FT2232h fifio interface) but at least i have a clean PCB to work with. As i won't be using all the 12 PCB i can same some to people interested to help with that project.
  15. voelker

    Papilio + ov7670 camera = spartcam !

    i modified my pcb a bit ... This pcb is meant to be placed above the papilio thus the cutout on the bottom right to let the power socket go through. I also added a mounting hole for the camera.