We reached a major milestone today. We are now able to reliably transfer data between two RFM69 nodes (our badge and a Moteino). Range testing was limited (about 40 feet through 4 walls) but RSSI on the receiving node had a 30 dB margin. This is without optimization of bitrate or sensitivity.

Turns out we had two issues:

1. Interrupt was not being set properly - we were using the default IRQ in the library of "0" but using pin PB12 on the microcontroller. Once we set the IRQ to the proper pin in the constructor suddenly interrupts started flying when data received.
2. Interference on the breadboard - The original prototype used for testing was completely breadboarded components (see below). The RF interference this created was extraordinary. Once we got the library working, we could only get it to send data when the jumper wires were held in a certain way. Most the interference was eliminated when we upgraded to a custom board (thanks OSH Park!) that moved the jumpers into copper. RSSI (when successful) was only -90 to -100dbM whereas now we're receiving reliably at -25 to -30 dbM at the same range.

So this completes functional testing of all the components of the badge. Due to the issues above we've put off working on the RFM69 SoC out of frustration. Now we get to add the social features to the software and solder up the other two OSH Park boards and microcontrollers for more testing.