Couple of project updates:
Hackaday has officially closed the Take Flight with Feather contest, they have said that they will notify winners near the end of January, so I'll continue on working away at it.
I'm still working on getting a useful demo up and running. I've currently got the LoRaMac-node code taking battery voltages, I'm just working on setting up the TTN based backend and data visualization part.
I've made another small change to the PCB. Offically it is at REV C0. Initially, I thought it would be cool to have the hard secure element on the board as I really haven't seen anyone working on it. Much later in the design process, I came across the MCCI Catena 4612. One of my first goes at a LoRaWAN Feather was very similar to this board using the same module. I had trouble with toaster oven solder reflow yields, so I opted for a discrete solution like what I have now. On any note, they incorporate an FRAM device which can store provisioning and frame counters without any worry of EEPROM wear out or data retention loss. Looking at the SOIC8 versions of the ATECC608A crypto chip and really any I2C FRAM device, one can see that the supply pins and the I2C pins are all in the same locations. The remaining pins are NC for the ATECC608A and are the address pins for the FRAM (similar to any 24LCXX EEPROM). So by simplying grounding the A0-A2 and WP pins on the PCB footprint, you could fit an FRAM chip or the crypto chip as you see fit.
I have a couple more almost built boards and I'll probably build a few with FRAM on them and bodge wire the pins to ground. That way I could maybe put together some code for the hard secure element and maybe some that utilizes the FRAM.
I also still intend to test out USB on the boards. USB would be useful mostly for charging and firmware updating but maybe some debugging/diagnostic data could be useful as well.
I also updated some files here on the project page to reflect some of the project progress.
I'd love to hear from anyone interested in the project as where to go next!