help with a small project - precise 1rpm motor & circut

[KrisBlueNZ]

BobK, thanks for doing the research.

I thought maybe a board with a motor driver and an accurate configurable digital control circuit might be used in robotics, but I guess not.

So you (the OP) will need a "dumb" driver board and a circuit to generate the required control signals from an accurate frequency source, presumably a crystal.

Normally this would be done with a microcontroller but there's a learning curve involved there. Someone on this forum might be prepared to code and program a PIC microcontroller for you for a fee.

Or you might be able to use something as dumb as a watch crystal and a ripple-carry divider (e.g. CD4060) feeding some flip-flops to generate the required control signals.

Google stepper motor control signal phase and look at the first ten or so results.

I would try to help more, but I'm currently a bit busy and I have little experience with stepper motors.

 

[danstar10]

thanks guys. what do you make of this?
http://www.piclist.com/techref/io/stepper/linistep/index.htm

 

[KrisBlueNZ]

It looks pretty cool but it doesn't generate the control signals entirely by itself - it needs a "step" signal which would have to be generated by a crystal-controlled oscillator with frequency division. Its focus is on microstepping, i.e. stepping a stepper motor less than one complete step, which you don't really need. Also, it doesn't have full bridge outputs so it can't drive all types of stepper motors.

Provided that you use a suitable stepper (which I can't advise you on), and provide the step clock (which I can help with), it might be a good option.

Other opinions anyone?