Mick in Oz, on May 3 2007, 09:15 AM, said:
Ken Moore, on May 3 2007, 08:26 PM, said:
I have a friend that is doing a home project using stepper motors (ink jet printer engines I believe) and parallel ports. I don't know the details, but I've watched it work and I do know that he is powering the stepper motor from a PC power supply that he slavaged from some where, not the port. The parallel port is for control only.
Thanks for that Ken. My project is involved with turning a screw that moves a mounted camera "in tune" with the earth's rotation, so as to do astrophotography. Right now I'm doing this manually, which is tedious and error-prone, which leads to blurry photos.
At any rate, I think I understand you, in that the "controlling" part of the motor would be transmitted to it via the parallel port...now I just have to figure out a way to design a cable that will connect to both the motor and the PC.
It is certainly possible to cobble all this together. But with a DC power supply, connectors, and a couple SSR's to pull it off, check out 868-RDK-STEPPER from www.mouser.com
. It's the stepper motor itself, with a premade microcontroller that you program and communicate with via a USB port, with all the support stuff already done. You basically just need to have a PC to run the software. Cost is $200. I can't imagine hand-rolling anything that cheap, and for a beginner, you'll get more out of a package like that one. And if you need to scale up/down, you'll get the confidence and knowledge you need to do it.
You may also want to look at Parallax and their BASIC STAMP or any of their other microcontroller kits. I'm almost positive one of them will cover stepper motors. They have extensive documentation in general and it's all online. These are very inexpensive and very easy to work with. I believe they have some relatively slow PWM code, so it should be very easy to build the stepper system you need.