I'm working on a line-tracking robot controlled with the Arduino Duemillanove and driven by 2 continuous rotation servos. I'm going to be using a Pololu QTR-8A reflectance sensor array (Pololu - QTR-8A Reflectance Sensor Array) to track the line, and I've mentally figured out how to get the tracker to move in a straight line, but I have no idea how to get it to turn, at least from a hardware standpoint. Can anyone recommend any sort of motor or other device that I can use to get my tracker to turn? I don't need any sort of sharp turning radius, just something simple. Any help would be much appreciated. Thanks!
but I have no idea how to get it to turn
The usual method is to stop or reverse one of the motors, but without knowing what your robot looks like, it's just guesswork.
Ah, I suppose I should have clarified. The controller itself mounted on a flat rectangle of plastic with the servos mounted at the back and a single caster on the front. The IR sensor is mounted in front of the caster, about 0.25" from the ground.
Reverse or slow down one of the two motors, and it will begin to turn. Adjust the speeds of the motors based on a line-following algorithm, and it will follow the line.
Same answer applies then - if you are following edge, staying between the edges, and you sense that now you are not anymore, you slow/stop one wheel so the nose comes around and finds the edge, and follow that, or go a little more and get back inside the line.
Wow... I can't believe I didn't think of that. Thanks for the help!
Course if the line veered right and you spun left, you'd just do a 180, up to your logic hw you deal with that.
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