The flight electronics comprise the control system for the rocket. This system is responsible for all of the sensor logging, valve control, ejection charges, and the data down link.
The CPU, or central processing unit, is a set of processors responsible for all high level commands and some of the lower level interfacing. This CPU board contains a LPC11U24 and two ATMEGA32P-AU. The LPC11U24 is an ARM processor is the I2C Master and sends all the data requests. It will log data from a gyroscope, accelerometer, manometer, and altimeter. The sensor fusion algorithm will be processes by one of the ATMEGA32P-AU. Code can be found for this module on GitHub.
The relay units are simple I2C modules that have an array of relays to control valves, igniter, and other outputs.
The down link unit sends a continuous stream of serial data over a 2.4Ghz band. This stream contains telemetry data, i.e. pitch, roll, yaw, and GPS coordinates. This is based on the Copenhagen Suborbital Sapphire Telemetry System. There is some great documentation for this module. The receiver has been designed around the HackRF One, which is a really cool rf transceiver.
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