That is mostly a power board, though it also serves as a serial -> SPI aggregator.
I forget the exact specs, but the jevois takes 1-2 amps at 5 volts to run. Powering 5 of them needs quite a bit of current. The roboRIO wasn’t going to be able to provide it. We built a custom board to do that (The USB connectors are to power the Jevois.)
Each of the Jevois runs Linux and has a serial connection back to this board. We send parameters from here to the Jevois (camera orientation is the main one), and then the Jevois sends back a list of the 3 best targets it found this time around. The Teensy then listens on all 5 serial connections, builds up a monster SPI packet, and transfers it back to the roboRIO.
We chose SPI as the communication path back to the RIO because we could get enough bandwidth, and control the timing well enough to make us comfortable.
I’m happy to answer any other questions.