Motorised Follow-Focus Project (help needed)

Hi,

I’m thinking of building my own motorised follow-focus system for my camera rig.

I want to do this with a stepper motor, mainly because of the relatively silent operation and the ability to manually turn the follow focus wheel if necessary.

I’m a bit new in this, but I’m intending to buy the following items:

  • NEMA 14 steppermotor

  • TMC2100 (stepstick) stepper driver (for silent operation and micro stepping)

  • wirewound potentiometer

  • AA battery holder for two batteries or Lipo battery

  • wormwheel

I’m still not sure what kind of microcontroller I should (or can) use, and I’ve seemed to hit a roadblock here. I need it to be very compact (like this https://www.youtube.com/watch?v=4daJXaEhVVA). Would a device like the Arduino Nano work too?

I’ve (hastily) drawn a little design of what it should look like.

http://i59.tinypic.com/10er6tt.jpg

Let me know what you think, suggestions are welcome

Cheers