Stribog the attitude sensing platform

Stribog will implement a platform for measuring user orientation relative to sides of world: azimuth, pitch and roll. the hardware includes a 3-axis magnetoresistive compass, a tilt sensor based on accelerometer ICs and a microcontroller to manage all.
The project consists of hardware and software sections, both under the GPL.
The hardware section includes all information needed for reproducing the system, i.e. schematics, boards layout in the form that most board manufacturers accept and so on. this is implemented using GPLd packages gEDA (http://www.geda.seul.org/) and pcb (https://sourceforge.net/projects/pcb).
The hardware is based on Honeywell magnetoresistive sensors, the most precise relatively low-cost magnetic sensors, Analog Devices MMIC accelerometers and optionally Analog Devices angular rate sensors. the microcontroller is a Philips ARM-based LPC2138. all these are expected to show about 1-degree precision.
It is also planned to use the platform motion data obtained from a GPS sensor.
The software will include uC program, which should solve necessary navigation tasks, and utilities to connect to GNU/Linux PC host. most likely the uC part will run without any OS. currently it uses only one external library (libgcc.a). stribog software is written in C and translated with GNU tools.
Auxiliary boards base on AVR microcontrollers. the programs running
on them are developped with AVR-libc/GCC/Binutils toolchain.
Other Software Required:
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gnu binutils (http://www.gnu.org/software/binutils/)
gcc (http://gcc.gnu.org)
gEDA (http://www.geda.seul.org/)
pcb (https://sourceforge.net/projects/pcb)