Quote:
Originally posted by Adam Y.
I remeber a while back on the official First forums that some team wanted to use a steper motor as a encoder. They said it was ok. This might work.
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Just off-hand, one of the problems I could see with this (or using any relative encoder with a decent resolution):
A stepper motor (as far as I can tell, from what I know about how they work) would act as a relative encoder, letting you tell which coil of three or four (or however many the motor has) is "active". I'm thinking of it as being a little dumber than quadrature output from an actual encoder. With a high enough sampling rate, this would be fine, because you could just continuously sample the outputs from it and track changes (keeping a sum of positive [CW, arbitrarilly] and negative [CCW, arbitrarilly] changes, for absolute angle). Assuming you use a standard stepper motor (200 ticks per rotation), in order to keep proper track of absolute angle (without using a custom circuit as a latching system), you'd have to keep the rotational velocity down to approximately 0.2 rotations per second (assuming the RC samples at 40 cycles per second, which quite possibly won't be the situation, next year *crosses fingers*).
It is an interesting thought, though.