I finally finished the design of my new PCB. It houses the GPS, charge
controller, and transmitter. This will function as a shield that will
mount directly to the Arduino Pro Mini via pin headers, thus
eliminating all wires (except to the solar panels) and decreasing the
weight quite a bit - to maybe 12 grams total.
The Arduino and this PCB will sit back to back. The PCB is the same
width as the Mini, but twice as long. The GPS, connectors for the
tether, and antenna counterpoise connector are at the top, and the
transmitter and antenna radiator connector are at the bottom. The
charge controller stuff is in the middle of the PCB.
There are high odds that something won't work. The PCB design's a bit
sloppy. But I'm to the point where I had to order boards to start
testing. They should be here in ~3 weeks.
The schematic and renders of the PCB front and back are attached.
Feedback or comments are very welcome.
I'm planning to launch a balloon with my previous design this Saturday
if the weather is suitable.