I will maintain the code for a while in a repository at http://code.google.com/p/ardu-imu-pilot/
If you try it out give me your feedback. It is similar to ArduPilot 2.4 but uses a different header file.
To interface ArduIMU to ArduPilot you connect the gps (ublox only) to ArduIMU, provide common power and ground to ArduPilot and ArduIMU, and connect the serial output pin of ArduIMU to the serial input pin of ArduPilot.
Comments
2.5.1 reads the IMU, does the new binary protocol to the ground station, and consolidates the PID loops. And perhaps adds better line holding algorithm using vector fields.
Thank you.
http://store.diydrones.com/ProductDetails.asp?ProductCode=BR-ArduIM...
I understand now how it all works together. Thanks again!
It describes the ardupilot main board. Then look through this manual - http://docs.google.com/View?id=ddjmqgw3_43gm6gvggf it describes how to assemble the ardupilot main board to its add on shield.
The ardupilot is available from sparkfun.com and the shield (sold also as a complete kit with cables and other goodies) is on this site's store. After you have assembled this, it will be time to connect your arduimu to this assembly. The ardupilot and arduimu communication over a serial link. The autopilot and arduimu code were made to work with each other, mostly for test purposes, by Doug.
To answer you questions, now that you have a system concept. Analog 3 is the airspeed input leading to the microcontroller on the ardupilot main board. (From the shield...down to the main board) The arduimu uses 6 analog inputs to measure sensors it has connected to its own microcontroller as you have observed.
Thus the system ArduIMU Pilot is a two Atmega328 microcontoller system...ardupilot and arduimu working together.
Note: Read the details of the software and upcoming releases that will make this more optimally.
This project involved firmware for both ArduIMU and ArduPilot (with the shield). The pressure sensor is used by ArduPilot for airspeed, which is used in the elevator and throttle control.