[jee7s]

If you are getting noise when the wheels are turning (by pushing or battery) but not getting it when the wheels are not turning, then it is most likely noise from your motor power lines. When you push the bot, the motors generate electricity because a DC motor is both a motor and a generator (depending on how you use it).

To reduce this problem, it would be best to locate the sensor near the controller to minimize the wire length. Also, avoid putting any major power supply line near the sensor. Consider shielding the sensor and the signal lines as well (an antistatic bag with an open end is not a quality shield).

If you need a replacement, there are many retailers who sell accelerometers. Sparkfun.com is a good supplier at a reasonable cost. However, this would count against your non-KoP spending limit.

-Jeff Erickson, FRC 41