Electrical / Mechanical engineer question...

[Donbecker]

I'm looking to find a cheap stepper motor controller that interfaces with a PC (serial, parallel, etc).

I'm also looking to find some cheap stepper motors.

It's a small project for physically turning control knobs on equipment via the pc, so the motors don't need to be hefty.

I have basic electronic/soldering skills, but I've never put together a pc board before.

Can anyone point me in the right direction? Anyone know of a cheap controller that is already assembled?

The equipment has alot of knobs (like 6 to 10 knobs) so it would be really cool to find a stepper controller that could run like 10 motors.

Thanks!

[Donbecker]

Here's one that allows up to six individual controllers to be linked to one parallel port, but it's pricey (and in the uk):

http://www.quasarelectronics.com/3179.htm

[Donbecker]

Here's a source for what looks like really cheap stepper motors:

http://www.allelectronics.com/cgi-bin/cate...per_Motors.html

Note that I've now read up on the difference between a stepper motor and a servo motor...I definately want to be able to finely control the turning of the knobs, so I believe at this point servos won't work and I need to use stepper motors.

[Donbecker]

Found a company in Australia, they make a USB based 3 axis (ie, 3 motor) controller.

They have several on ebay for $35 (plus $15 for shipping to the US).

http://cgi.ebay.com/USB-Stepper-Motor-Cont...1QQcmdZViewItem

[Donbecker]

This page looks promising...

http://electronics-diy.com/stepper_motors.php

" Some drivers might also come with a frequency generator / timer that is used to control a rotation speed (LM555 / NE555) and digital IC such as 74LS194 that will use pulses to generate a stepping mode.

In this project, on the other hand we will use computer and a program to perform that functionality. "

It uses a 16pin ULN2003 IC that costs around 64 cents.

Looking for the IC online, I see all these parts that are "ULN2003.." but they have letter designations after them.

Anyone know what those mean?

[Donbecker]

Well I think I found a much more simple solution.

Digital Potentiometers!

http://www.analog.com/en/subCat/0,2879,761...F0%255F,00.html

[Bigfoot]

Having a nice conversation with yourself to boost post count????

J/K

[Eddie44]

Having a nice conversation with yourself to boost post count????

J/K

I thought it was just me

[nort99]

glad u talked you way thur this. :D

[Donbecker]

Well kinda.

I started getting all setup last night. I unsoldered the gain control from my guitar amp and ran wires out to a bread board.

I measured the pot to get the value for it.

I then hooked the pot up to the bread board to double check that I hadn't broken anything.

For some reason though I could barely get any volume out of it.

I'm wondering if I have some crazy high resistance in the wire or breadboard.

The gain pot also had the body grounded to a pad on the circuit board so that may be it as well (I didn't stub that connection out, I just did the 3 wires for the pot).

I'm thinking for a quick test tonight I can just pull the wires from the breadboard and put them together to simulate having the control all the way up.