The adafruit Feather M0 WiFi arduino board has turned out to be the perfect board for the Master Control Panel. There are many pre-made ‘wings’ that can connect together through a common set of pins, including the OLED screen on the top of the MCP, and the servo controller.
Since the board diagrams are available from adafruit, I was able to use their template to create a printed circuit board and have it made by OSH Park. The MCP I/O Wing plugs directly onto the bottom of the other board, allowing me to neatly plug all of the components into it with tiny board connectors by mill-max.
I experimented with a very small surface mount component to invert the signal going to the camera. It replaced five through-hole components, but it is only ~5mm square. It was a pain to soldier, but I only had to do it once, and it allowed more space for more I/O ports.
The board has an ethernet port and I/O connectors for the camera connector, USB, 12V in, Analog Out, reset and power buttons, and the long range radio upgrade that are part of the case. The board can be reconfigured with a different arrangement of I/O pins, and used as a receiver at the other end of an ethernet cable connected to the MCP. The Ethernet routes power and data to I/O pins and other Feather boards..