Call for Code: Elektor Wheelie Open Firmware

[thomas scherer]

I've just posted an invitation to optimise the Wheelie firmware in my blog http://ewheelie.blogspot.com/.
A starter version of a new simpler code with english comments you will find in the german sub-forum where you can download the source code and a ready-to-flash hex file.'

[thomas scherer]

There are more new versions of the firmware in the german sub forum. The source code comments are in english.

[pbisiac]

Hi all, I Just finished to build an Elektor Wheelie. I programmed the ATMega32 with "official Elektor firmware". My hardware is slightly different from wheelie, but motors and electronics are the same.
The problem I am facing is: when I start wheelie (pushing the presence button) for some fraction of second the algorythm seem to work (motors move slowly, sometimes in the same direction sometimes in opposite), but then both motors start to accelerate until 17V and they never stop. I made these trials with wheelie standing still on a tripod.
I made a little change on Elektor hardware: I wasn't able to find the IDG-300 gyroscope, so I redesigned the gyroboard with an ST LPR550AL. The sensitivity is the same, ±500 °/s, the Zero-rate level is different (1.23 V for LPR550, 1.5 V for IDG), but I don't think ths should be a problem, as firmware makes a "zero point" at startup. I made my tests on this tripod, and the outputs of acceleremeter sticks to 1.5 V, while outputs of gyroscope sticks to 1.23 V (perhaps some little oscillation due to motor vibration, but the problem remains if I disconnect motors).
Do you have any idea that could help me ? Thank you very much.

Paolo Bisiach

paolo@bisiach.it