After a month and a half of solid misery, I'm having to change the design - the original design had 4 cameras operating on a shared SPI bus, meaning each Beagle controlled 8 cameras over two busses.  Unfortunately, this led to an analog nightmare of noisy circuits and corrupted data.  I'm a software guy, I did what I could and decided a strategy change was better than falling down the rabbit hole of analog EMI interference and other such mental anguish.  Right now, I am firmly of the opinion that Kirchoff can go straight to hell.  :-)

So, the design is being reworked to drive single cameras off the SPI buss, i.e. there will be 12 Beaglebones driving 24 cameras.  This is actually a good thing, indications from the downstream processors was that they'd be a lot happier if more and better work was done upstream on the images, and we've got enough spare cycles now to dump OpenCV onto the bones.

So stay tuned, next generation rings are being ordered and built out -  indications are that real time video will be available in lower resolutions, and that max resolution of 1600x1200 still comes in at a solid 3 frames/sec

Oh, and I would have tried with Raspberry Pi Zeros, but apparently, you can only order one at a time -  I elected to completely remove all Raspberry Pi's from all aspects of the project, because I think the vendors are playing games. I can get bones, I trust bones, so that leads to a nice uniform environment.