Tag Archives: AFSK modulation

High altitude balloon tracking with the ATmega644

A Maker by the name of Ethan (and team) recently designed a low-cost open hardware/software high altitude balloon tracker with sensors that effectively form a mesh network with a master node.

The above-mentioned platform – powered by Atmel’s ATmega644 microcontroller (MCU) – is equipped with an onboard GPS module (NEO-6M), a micro SD card slot, a 300mW APRS (144.39MHz) transmitter and convenient headers to plug an XBee radio.

As HackADay’s Mathieu Stephan notes, the hardware is tasked with obtaining wireless data from various slave platforms, storing it in the uSD card while transmitting the balloon position via APRS along with other data.

“It’s interesting to note that to keep the design low-cost, they chose a relatively cheap analog radio module ($~40) and hacked together AFSK modulation of their output signal with hardware PWM outputs and a sine-wave lookup table,” Stephan explained. “The slave nodes are composed of ‘slave motherboards’ on which can be plugged several daughter-boards: geiger counters, atmospheric sensors, camera control/accelerometer boards.”

Interested in building your own Atmel-powered modular high altitude balloon tracker with mesh networked sensors? You can check out the project’s official page here.