Tiny4FSK is an extensible high-altitude balloon flight computer with built-in tracking using the Horus Binary v2 tracking system.
Tiny4FSK uses:
- the SAMD21 microcontroller, which is an ARM Cortex-M0+ MCU
- the TPS61200 boost converter, which is adjusted to output 3.3v
- Si4063 radio module, which I use on the 70cm band
- ATGM336H gps module - pretty cheap GPS module which works in airborne mode (>18km)
- integrated BME280 temperature, pressure, and humidity sensor
The code uses the Arduino framework to make it accessible to beginners

This project was graciously sponsored by PCBWay. They provide low-cost PCB fabrication and assembly services. The pictured PCBs were fully assembled by PCBWay's services! Check them out at https://www.pcbway.com/.