Re: Sensors
 

When it comes to encoders, a quadrature encoder is particularly useful. If you take a normal (not magnetic, but light-based) encoder apart, you'll find a light source, an "encoder wheel" with a bunch of holes and a light sensor. Basically, the light shines through the holes. When the wheel spins, the receiver counts how many holes have been seen. Normally, the light sensor can't tell if the wheel is spinning forward or backward, but a quadrature encoder has another light sensor and another set of holes on the wheel that are offset from the first set. There are four distinct "states" the encoder can be in, so it knows if it's counting up or down.

Re: Sensors
 

So magnetometers don't work well on the robots?

Re: Sensors
 

Magnetometers work on robots however that calculated heading most likely will have very little relation to the actual heading of the robot. The hard iron effects can be compensated for. It's the motors that are the big problem. We haven't given up on them yet. Depending on the robot and game a magnetometer may be able to work. Our robot this year has way to many motors all over and there is no place to mount it to get it away from those fields. Our robot last year may be a better candidate. These are the issues we will look at this fall.