Stepper motor control

[nzlowie]

Hi there
I'd like to be able to drive a small stepper motor with a stand alone box where a pot would control the direction of the rotation.
What I'm wanting to do is use the stepper motor to turn a focusing ring on a manual camera. Instead of turning the focus ring I'd turn the pot to focus each way.

Any idea's on the simplest way to do this?

Many thanks Dave

 

[Bluejets]

Servo and a servo drive board.

http://www.ebay.com.au/itm/RC-Helic...534972?hash=item4d363e4f3c:g:BHcAAOSwX~dWrpQ4

 

[nzlowie]

Thanks Bluejets
Sort of what I'm after..... due to the gearing though I need more than 180deg of rotation.
Was thinking about turning the pot one way and this would keep turning the motor until the pot was returned to the mid point. Could even be a 3 way switch for that matter.

 

[BGB]

IMHO, this seems like a better use-case for a small DC gearmotor than for a stepper. a 3 position switch (DP3T) can be wired up to the motor, which connects it as-appropriate to a battery.

controlling a stepper is a bit more involved, and it isn't really obvious what if-any advantage it would have in this case (unless you already have the motor and just need a way to drive it).

 

[nzlowie]

Thanks BGB

Perfect, that's a better idea. I didn't think of that, as always simple is best!

Cheers