No heartbeat. But I ran a link between two ports on a laptop and that worked fine, so I'm thinking that the radios are good and set up right.
My initial problem was that I selected the wrong port when uploading firmware to the flight radio, so I actually uploaded to the ground station.... twice.
I also discovered in the process that I only have 3.8V on the 5V, and 2.7V on the 3.3V port pins on the board, which might explain why it's not working with the board, so that's on top of things to fix. Guess I toasted a diode at some point.
Edit: Or not. Can I trouble one of you guys to measure the voltage on the 5V and 3.3V I2C-ports with no USB connected. Also, is your VBUS diode lit when USB is disconnected. As soon as I connect my USB the voltages are correct.