A lightweight tracking and logging computer for high-altitude balloons or other tracking.
Basic components: SR_FRS_1W module SD card Adafruit MTK3339 module Atmega328 (or larger)
All Hellschrieber code is directly from Mark VandeWettering at: http://brainwagon.org/2012/01/11/hellduino-sending-hellschreiber-from-an-arduino/
It was modified slightly for use here.