Stepper Motor controlled by a Microcontroller..help 2

[Va5h15t]

Hi, im new to this site. Found it very helpful and thus I registered.
I am currently in the process of designing a microcontrolled fibre optic illuminator. I am using a Halogen light source.
the main issue now is to create a colourful light effect using colour wheels, and twinkling effects using gobos.
I found out that stepper motors are the best for this purpose since they can be controlled with a microcontroller.
My concerns are:
How to interface the stepper motor to move Cw and CCW commanded from the microcontrller. I better use an 8051 uc sicne I have studied these and I know C programming.
For example, lets assume a filter of 10 colours, this gives 36degree of movement, and incase of a 200stepmotor, it would mean (360/200)*36 steps for each colour change.
this would ideally be controlled by uc which will give the user the choice to choose colour(out of the 10 colours)via a keypad or something similar and the choice of speed as well as the choice to keep the motor in place on one colour for a specific moment.
To incorporate the twinkling effect, Im assuming another wheel(one with gobos) should be used, which in turn will be controlled by another motor and inturn be controlled by the 8051, in such a way that when the gobos is to be used, the colour wheel is stopped and the gobos wheel moves.
Im not actually finding a way to place the two wheels once at a time infront of the light source, should be possible using timing belts?
If you have a better idea for part or for the whole project, please do mention it.
I found out that its easier to control one motor using the LM293 IC.
ps: I read a lot about steppers, and the unipolar would be the best for this purpose, correct me if im wrong.

I know this is very long and i apologize.

Hope to hear from you soon

Thank uch in advance,
Vashist

 

[BobM3]

How much do you want to do yourself? There are fairly inexpensive stepper motor controllers:

http://www.jrkerr.com/index.html

 

[Va5h15t]

thank you for the link bobM3. its really helpful for information on PIC driven steppers.
What i need to do is to conrol the stepper with an 8051 microcontroller and the motor should be controlled manually or set automatically by the 8051. Speed of motor and waiting for 5seconds at a specific color(64.8 steps in the case above) when a button is pressed.

 

[itsmoked]

You should really google for "stepper motor control". There is a huge amount of good stuff written on this. Steppers are pretty easy to control, but there are some little pitfalls too. There are sites that will expound on unipolar verses bipolar, and microstepping. An 8051 could probably run 4 or 5 steppers depending on the drive type.

Also check the robotics hobbyist sites as most robots use steppers.

Check the Microchip.com site for application notes on driving stepper motors.

Keith Cress
kcress -

http://www.flaminsystems.com

 

[mcgyvr]

TONS of info on google
First site when searching for "8051 stepper"

http://www.freewebs.com/maheshwankhede/stepper.html

even has coding

also 8051projects.com

 

[mcgyvr]

sorry 8051projects.net

 

[BobM3]

Oops, I thought Kerr Company made controllers for stepper motors also. The Microchip site is great. For starters you might try this location:

http://www.microchip.com/stellent/idcplg?IdcService=SS_GET_PAGE&nodeId=2125&param=en026178

 

[Va5h15t]

thank you very much for the links guys..s it is..i did a lot of research on the internet since a long time and here are the references i found :
STEPPER MOTORS:

http://www.midnightkite.com/satstep.html

http://www.doc.ic.ac.uk/~ih/doc/stepper/

-

http://www.cs.uiowa.edu/~jones/step/

- Tutorial by Douglas W. Jones, University of Iowa

http://www.ams2000.com/stepping101.html

- ADVANCED MICRO SYSTEMS LTD

http://www.electricsteppermotors.com/stepper/

http://www.electojects.com/motors/stepper-motors-1.htm

http://www.dmx512.com/web/light/dmx512/index.htm

http://gotwind.org/diy/stepper_motor.htm

http://en.wikipedia.org/wiki/Stepper_motor

http://www.reuk.co.uk/Stepper-Motor-Basics.htm

http://www.piclist.com/images/

http://www/hobby_elec/e_step.htm

http://www.howstuffworks.com/motor.htm

http://en.wikipedia.org/wiki/Electric_motor

http://www.simplemotor.com/

http://fly.hiwaay.net/~palmer/motor.html

http://www.educypedia.be/electronics/motorstep.htmhttp://www.educypedia.be/electronics/motorstep.htm

http://www.elementinc.com/

http://www.st.com/stonline/books/ascii/docs/1679.htm

http://openbookproject.net//electricCircuits/AC/AC_13.html---BOOK

ON AC MOTORS AND ELECTRONICS

http://www.imagesco.com/articles/picstepper/01.html

http://www.reuk.co.uk/Stepper-Motor-Voltage-Doubler-Circuit.htm

http://www.c-realevents.demon.co.uk/steppers/stepmotor.htm

http://www.techlib.com/electronics/stepper.html

http://howthingswork.virginia.edu/electric_motors.html

http://gotwind.org/diy/stepper_motor.htm

http://zone.ni.com/devzone/cda/ph/p/id/287

http://www.arrickrobotics.com/motors.html

http://www.sscnet.ucla.edu/geog/gessler/topics/steppers.htm

http://www.hsi-inc.com/stepper_motor_theory.php

http://www.micromo.com/n390885/n.html

http://sciences-physiques.ac-dijon....iquee/MoteurPasAPas/Reluctance/Reluctance.htm

http://col2000.free.fr/pasapas/pap_mot.htm

http://sitelec.free.fr/cours/abati/flash/pas.swf

- ANIMATED VERSION OF STEPPER MOTOR

http://www.ac-nancy-metz.fr/pres-et.../cours/electrotechnique/moteurPP/moteurPP.htm

http://www.edn.com/archives/1996/092696/20di3.htm

http://chaokhun.kmitl.ac.th/~kswichit/2051/stepper/stepper.htm

http://www.ducttapeeng.com/steppermotors.htm

What I am looking for is an idea of how to turn the colour wheel in front of the light source whilst using the gobo wheel to provide a twinkling effect.
turning two wheels in front of a light source will give a different effect compared to turning one wheel at a time(and thats what I need). Using timing belts and gears, would that be possible? Im sorry I am not so much conversant with mechanics and mechanical parts.

I really appreciate your help and the useful links everyone.
I just need some ideas and then I will try to work on these ideas with your help.

 

[PHovnanian]

I don't know about the effects you mention. You will have to define how these two wheels need to be turned relative to each other and the light source.

Simplest design would be to turn them together with one motor on one shaft. But perhaps that's not what you want. If one wheel can turn at some multiple of speed relative to the other. then simple gears, friction wheels or belts and pulleys will do. If the wheels must turn at variable speeds relative to each other and the source, or vary their relative angular positions, then you are going to have to spring for two motors and the driver hardware to support both of them.