[TimeOut]

Morning Jim,

The encoders don't actually keep the position, they tell you how many clicks away you are from where you last zero'd the encoder count. So, if you have 360 ticks (I'm not sure how many there are on these encoders) then each tick would be 1 degree. As the wheel turns forward the tick count increase, as the wheel turns backward the tick count decreases.

By counting the ticks you can tell how far you've traveled. By adding a time factor into you can tell how fast you are moving. After doing the math for any gearing and wheel diameter you can determine distance moved.

The Mindstorms Encoder keeps the count internally and uses the count to determine an approximate 'position' of the motor and to 'move-to' a specific position.

This may have to be accomplished manually with the FTC equipment; part of the fun eh?

If you need the position to control a manipulators position, you may want to consider using a potentiometer instead of the quadrature encoder. The can be easier to deal with when you do not need continuous rotation (like a drive train).

The typical application for the quadrature encoders is on drive trains to help with measuring distance, turning the robot specific angles, and helping the robot drive straighter (especially in autonomous mode) by either implementing PID controller or comparing the left/right encoders and adjusting speed when one gets too far ahead of the other.

Sean