Hi all. I have been flying tricopters for a while now and have started looking for an open source dedicated controller rather than using 4 heli gyros. The Aeroquad looks ideal for me. I have a background in electronics and programming so I like something that is very hackable. I took a quick look at the code and it looks to be pretty simple to add support for tricopters as well. M Holder's mixer table idea would work well for tris as well as quads, hexas etc.
Anyway, during my research into tricopter stability I did some ESC tests. Most ESCs are designed for use in planes or helis where a smooth response is fairly important. Most ESCs have a low pass filter on the throttle input. This is added to make throttle response smooth and irons out any glitches but it very bad for multi rotor craft. After doing some research I decided to try re-flashing the firmware in some ESCs with the the firmware written by Bernhard Konze AKA Quax. This is specifically designed for fast response. Here is a video of my test results.
A flight test in a strong wind. Sorry about the really odd video angle. I strapped a keychain cam to my head and didn't realize it was at an angle.
The stability improvement is impressive. Apart from obviously having to keep flying against the wind the wind had very little effect on flight stability. Some others have also tried the gyro test in my first video on various ESCs and Turnigy plush do quite well. Castle creations ESCs do very well if you turn the throttle damping right down in their configuration software.