Hey everyone, thought you may be interested in my latest project. I’m working on making the smallest lightest APRS weather balloon tracker I could manage and this is the result. Its 1.75" x .75" runs off 2 AAA batteries and weighs under 55 grams flight ready. It’s got an ATmega 328P running the arduino bootloader and a modified version of the Trackuino firmware, a ublox MAX-M8Q GPS receiver, sparkfun gps chip antenna, radiometrix hx1 300mw 2 meter transmitter, sht21 humidity sensor, and bmp180 pressure sensor. Battery life is around 12 hours though that could be extended with some software fiddling. The board and source code are open source and will be released soon™. For more information and pictures check out our site at www.tracksoar.com