which sensor to use

[DuaneB]

Originally Posted by tilky

we want to be able to read the angle of the robot relative to horizontal so when we go on the bridge, it will balance itself. we got it to work, but we have to reset it before and i didn't know if there was a better way

Ah, you want to measure tilt angle. The accelerometer (on the same board as the gyro, but with a separate digital interface) will work well for that. Keep in mind that the vector magnitude will be higher than 1G while the robot is moving, so you may need to compensate for that.

[tilky]

so there really is no "perfect" sensor to use?

[Alan Anderson]

For measuring tilt? A multi-axis accelerometer is the only reasonable choice. But no single sensor is "perfect". If you want the best possible information about the robot and its environment, you have to use many different sensors and a good algorithm for combining imprecise, noisy, and sometimes contradictory signals.