ADS-B / FLARM receiver with integrated rechargable battery and antennas (modified version of this awesome model)
Compact case which holds Stratux components, a rechargable battery, its two antennas and GPS receiver. Runs from battery or USB power. Plugging in/out USB switches power supply and charging without interruption (see PowerBoost 1000 description for details).
Default settings should do fine (worked well with 0.4 mm nozzle, 0.2 mm layers, no supports). I'd recommend printing in PETG or ABS since PLA would deform easily on sunny days.
Besides standard Stratux components, you need Adafruit PowerBoost 1000 (ADA2465), MakerFocus 10,000 mAh rechargable LiPo battery, a 10x15 mm rocker switch, some wires and basic soldering skills.
I chose to power the Pi via test points PP1 and PP5 instead through GPIO headers (AHRS module). Feeding power into GPIO pins circumvents the over-voltage and over-current protection of the Pi (more detailed explanation here). Overload protection can prevent smoke and fire in case of a hardware fault (which you really don't want to deal with during flight).
The author remixed this model.
Increased case height by 1.5 mm so that it can fit a bigger battery (e.g. I used the MakerFocus 10,000 mAh rechargeable LiPo battery which had good availability here. It has same dimensions except that it's 1.5 mm thicker)
Replaced the power pushbutton with an on/off rocker switch (I used one of these common available 10x15 mm rocker switches). In the cockpit, I prefer to use toggle switches that act instantly, like everything else does in the plane. Turning off Stratux without shutting down isn't an issue here, since Stratux mounts its filesystems readonly and can deal with sudden power loss.
By flattening bottom and top faces of the case, parts can be printed without bridging or small lines on the first few layers, which makes them easier to print on FDM printers.