The task is to create a stack of 4 Ras PI boards, connect to the 3rd of them using a standard CSI camera, and the fourth one should collect pre-processing data from each board with a camera and calculate something common (not the essence of the question what exactly). It should work in real time with a resolution of HD and at a speed of at least 40 FPS (which one board with one camera fully allows). The card with the camera does not give the images themselves, but the data on the contours selected from them (that is, the traffic is relatively small, no more than 2% of the image size). Please advise two points:
- Communication medium - Ethernet, WI-FI or Bluetooth - if Eth, then HUB has to be attached somewhere else, if it is a mobile device (for example), then I don’t even know how to be with a hub ... Bluetooth 4.1 is very attractive but never worked - will anyone recommend a library to set up a connection for a group of boards? I did not find anything ... if wifi is not easy either - one of the boards will then be an access point, and nowhere is it possible to write on RasPI like that ...
- The exchange protocol (when there is already a communication environment) - the very first thing that comes to mind is 0MQ - this is probably correct, but can someone have experience of such things and other recommendations? Will it be possible to achieve synchronism + -2 frames using 0MQ, provided that everything else — the network and the boards — works perfectly?
hostapd(hostapdfor Linux SoftAP they are the ones who go up). This is not the first link, but the most, let's say, neutral :) Bash is the same in the Russian-speaking community, which is in English-speaking :) - D-side