VEX inputs

[ChrisH]

Originally Posted by Gdeaver

Check the Radio shack website to find a local store with the encoders. I bought a set and am playing with them now. I must be doing something wrong or there is allot of latency in easy c. It drives straight with quite a wobble. These aren't greyhill quality or precision.

I bought a set about a month ago. Quadrature would be a real nice addition, but I'm not sure how to go about that. I didn't have any trouble getting it to drive straight if I was just measuring distance. My Squarebot could repeatedly drive a path including straights and turns with reasonable precision as long as the surface remained the same. Move to a different surface and the turn angles changed. Not an unexpected result.

I have recently started working on velocity contol. I have a Proportional algorithm working on one side. It does oscillate a little when running free. Again this is not unexpected, in fact I would have been more amazed if it didn't happen as it is characteristic of this sort of control. PID's always oscillate, the question is whether or not the magnitude is acceptable. Gdeaver were you counting clicks or controling speed?

I haven't added the second side to see if it drives straight yet. Maybe in a few days. I've been too busy with going to FLL at Legoland and setting up next weekend's tournament at CSUN.

Has anybody done anything with Potentiometers?