i have built an IMU of my own design into my homebrew RC system on a fixed wing airframe.
i am using a MMA7260 accelerometer on an ebay "prototype PCB" along with some rate Gyros for the IMU which is proving quite robust while gliding.
the problems start when i power the motor on.
the accelerometer readings become highly erratic with a gain in output voltage from the
MMA7260 on average.
the physical distance between the motor/speed controller is around 300mm.
the accelerometer is powered by a 3.3v regulator on my RC board which is in turn powered by the BEC in the
the problem starts to present when the motor is drawing anything more than a few hundred mA but gets worse with more power draw.
i have eliminated mechanical vibration by testing the system with the accelerometer mounted outside the airframe.
i've tried adding smoothing capacitors
on the power to the accelerometer and associated microcontroller but have not yet tried any thing else to test/clean up the power supply.
i'm looking for advice as to the most likely cause of this interference before i start ripping it all apart searching for the root cause.
magnetic / power / something else i have not considered?
some details on the components i am using:
my home brew RC system: http://sites.google.com/site/mrdunk/
MMA7260 accelerometer "prototype PCB: http://cgi.ebay.ie/3-Axis-low-g-Accelerometer-MMA7260-prototype-PCB...
motor controller: http://www.giantcod.co.uk/hobbywing-pentium-18amp-brushless-motor-s...
i have no experience with accelerometers so any pointers on where to start troubleshooting this would be appreciated.