Newb needs help!

skinnytie

Ok, guys - I'm stuck here.

I am a film maker and hobby-level electronics enthusiast. I have a project in which I need a way to pull focus (turn the focus ring on my panasonic dvx100a prosumer video camera) to 3 preset points via a remote.

I have been told that I can create something with STAMP, and that I could find the geniuses in this forum to help me work this thing out.

I'm a programmer by day, so the code isn't an issue - but the actual hardware situation is boggling my mind.

Anyone care to help?

Details:
- Must turn focus ring on camera to 3 different points
- must be triggered (each point seperatly) by remote control
- must have its own power (I've heard tell that a 9v will do)

-skinnytie-

Bruce Bates

Skinnytie-

Does the focus ring have a gear or gear-like circumference?

Regards,

Bruce Bates

▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
<!--StartFragment -->

T Chap

Also, how many revolutions/degrees does the focus ring turn to achieve the 3 positions?

LSB

I think I'd use a stepper motor. Steppers move a predefined fraction of a turn per pulse and are easily positioned to preset points. An example: I have some that are 200 steps per revolution--each step 1.8 degrees. Program a pause, or even a variable pause, between steps to control speed and, of course, >200 steps is multiple rotations. Gearing and 1/2 steps can refine positioning too. Sound like what you want? I think Motor Mind modules are available for steppers and easily handle the volt/ amp requirements of the size you need (I'm thinking pretty light duty); interface easily with stamps for a 1-2-3-4 approach.
Another option would be to go with PID, rotational sensors, and motor feedback, but unless it's imperative that motors never mis-step, steppers are far easier for a hobbist.

As for the remote in, you didn't say RF, IR, or ultrasound... Still, I've seen code for everything from SONY universal remotes to keyfob type transmitters--even roll your own with hobbist knowledge. R/C Tx/Rx pair interface with PULSEIN. Request specifics as project develops.

Mark

DaveG

Are you familiar with the Bogen/Manfrotto 521p Remote Controller? It's designed for your camera.
There is also a wireless version out there somewhere.

DaveG