An Attitude and Heading Reference System (AHRS) built on top of a SOC Robotics IMU6410 board and powered by an Atmel ATmega1284P 8-bit AVR RISC-based microcontroller.

This was a small step on our personal Virtual Reality head-mounted display technology project. It allowed us to simulate a gameplay in which the device would follow any movement made by the player's head. See it in action! (click for a video):

This project serves as an integration and test bench for different IMU and AHRS algorithms. Currently, the incorporated implementation of signal filtering is the one made by Sparkfun for their 9DOF Razor IMU board: the Razor AHRS firmware.

Other algorithms which could be integrated in the future includes the implementation from Android, the sensor fusion algorithm made by Sebastian Madgwick, and the FreeIMU implementation.

Folder structure:

• src/avr includes all the source code for the firmware which will be loaded on the board's microcontroller.
• src/avr/board contains a modularized skeleton of code used to handle the most common functionalities of the Atmel AVR uC used for the project: board initialization, access to the EEPROM, SPI channels, Serial Port communication and time measurement functions.
• src/razor contains the implementation of the different AHRS filtering algorithms. This code is shared between the board C code and the application C++ code.
• src/win contains the desktop application which serves as a test bench for the sensor board. This application can receive the sensor inputs in a variety of ways, either in RAW form (from the sensors output) or in calculated AHRS positions, and store them for further processing.