Screen Shot 2016-06-07 at 20.14.51

Hacking the breakout board – 1st iteration

This is continuation of “Breakout board research” and part of  Chihuahua-VR platform (see also VR tags).

Schematic

The camera modules requires 4 levels of powering: 1.8, 2.8, 3.3 and 5V. It is also recommended to power up the camera module in the order:

  • PWRDN to high – CN4-12
  • RST to low – CN4-10
  • SV1-2/3/4 to low
  • 5V comes first
  • 3.3V comes 50ms after 5V – set SV1-3 to high
  • 1.8V comes 50ms after 3.3V – set SV1-4 to high
  • 2.8V comes 100ms after 1.8V – set SV1-2 to high
  • PWRDN to low comes 50ms after 2.8V
  • RST to high comes 200ms after PWRDN is low

schematics-j100-ar1820mod

Short list of parts at Farnell:

Board

I have routed this board approx. 90% manually. For some reason the auto-router of freeware Eagle PCB was not able to finish the job (even with 2 layers).

board-j100-ar1820mod-mask

Manufacturing

This was a huge challenge! I have developed this board in my tiny London’s kitchen using the parts I have bought in the local Maplin shop in Camden (pcb board, etchant, transfer foil, marker and laser printer).

The results and quality does not amaze, but it was a quick solution. Some of paths are made very bold because of difficulties in transferring and etching.

Screen Shot 2016-06-07 at 20.17.30 Screen Shot 2016-06-07 at 20.14.09

Testing

Test has failed! My custom PCB and wiring seems to be correct according to the documentation of J100 and e-CAM130_CUMI1820_MOD. There is a problem in providing I2C interface to the camera module. Additionally there is missing driver for AR1820 on the Linux for Tegra 23.2

I will have to evaluate a hardware workaround for missing I2C. The driver might be already existing and provided by e-con Systems (it was used for Jetson TK1 platform with the same module).

Screen Shot 2016-06-07 at 20.15.17

Conclusion

During the test phase I have found plenty of bugs. Main problems are:

  • J100 and I2C wiring error – not connected to the Jetson TX1 dedicated camera I2C
  • missing AR1820 kernel driver

See also the other problems listed on the image below. The diagram below is a very rough overview of what I have found and learnt so far…

Blank Flowchart - New Page

Resources

Multiple parts of my blogpost have its source in remote articles, blogposts and wiki for which I have no rights. I am not able to link all external sources to my blogpost. I would like to say thank you to everyone who shares the knowledge publicly. If you think I have illegally used any of your thoughts, products, patents please let me know and I will remove related information asap.

© COPYRIGHT KRZYSZTOF STASIAK 2016. ALL RIGHTS RESERVED