FeatherHAB is a lightweight, small, and inexpensive balloon tracker. It tracks the location of a balloon with GPS and broadcasts the balloon’s position to the APRS network on 144.390MHz. The tracker is built around a Ublox MAX8 GPS module and a custom RF transmitter designed with the Silicon Labs Si446x transceiver IC. Power is supplied by a single-cell Lithium battery, which runs through a tiny buck-boost converter to power the system. The total weight comes in at about 2 grams without a battery.