controlling stepper motors through web cam movemen

Forum 2005-2010 (read only) Software Interfacing
1

Hi, I am an artist only beginning to use arduino

I have been making some basic drawing and painting
machines and so far I have been using some very basic software that turns
a PC into a CNC machine, communicating to a driver box and powering
stepper motors.

I am now keen to make the pieces more interactive and am trying to make a
painting machine that will paint according to the movements of the viewer,
using a web cam to monitor the viewer and an arduino micro controller to
move the stepper motors in real time.

I have spoken to a friend of mine who has some experience of arduino who
was able to find some processing code that would turn movements on a web
cam into a drawing on the computer screen-

It needs a plugin to be added to processing, from the JMyron site

We were thinking that we should be able to tweak this to drive some
stepper motors, at least i hope my friend will be able to. Trouble is he
has little experience of stepper motors.

I have got the motors kind of working through the arduino, all though they move very slow. I am desperately trying to find some way of translating the processing code for JMyron into x and y coordinates to move the the stepper motors. I have an art exhibition opening next week and have 3 pieces that all rely on this working. I have bitten off more than I can chew so any help you can offer would be amazing!

Any advice you have would be greatly appreciated.

Thanks for your time.

Rhys

2

Would you tell us a bit more? It might make it easier for us to help.

Did you use these to get the stepper motors working:

or something else?

What types of stepper motors have you got?

It sounds like you have quite a lot of 'moving parts' to get working.
How might you remove parts to simplify it, and still have something that is useful for you?

GB

3

Hello,
I am one of the people helping Ringo with the project. We are using a Xylotex driver box with Xylotex bipolar four wire stepper motors.

The line of communication runs from the camera, to processing, to the arduino board, to the Xylotex driver, then to the motors.

One of the problems we are having is figuring out how to get arduino to communicate to the driver box. The driver box has a parallel cable input, and only two pins of input per motor; steps and direction. We've gotten the motor to turn by sending 5v thousandth of a second 'on off' pulses, and we've gotten it to change direction when a 5v signal is sent to the directional pin. The problem is that to get the motor to run forward and backward smoothly we connected the ground pin of the arduino to the ground pin of the driver box's parallel port, and when ground is connected the motor will only run at half speed, which will not be fast enough for real-time interaction. We have been able to achieve max speed from the motor while ground was connected through a potentiometer and tweaked to a certain spot, but while set up that way the motor only goes backwards slowly and jerkily.

The other problem is coming up with suitable processing code to make the motors move according to the viewers movements.

The datasheet supplied by Xylotex (Xylotex CNC Sytems) doesn't, as far as I can tell, explain what inputs the driver "wants" or why grounding it makes it work correctly but slower.

If possible, we want to figure out how to get the motor running at full speed (which we achieved with a yet unknown amount of resistance on ground) but with full ability to do so in both directions.

You can see examples of ringos work here-

http://rhyshimsworth.com/work%207.htm

As you can see, he has been making some basic drawing and painting
machines and so far I have been using some very basic software that turns
a PC into a CNC machine, communicating to a driver box and powering
stepper motors.

we are now trying to make a
painting machine that will paint according to the movements of the viewer,
using a web cam to monitor the viewer and an arduino micro controller to
move the stepper motors in real time.

I have spoken to a friend of mine who has some experience of arduino who
was able to find some processing code that would turn movements on a web
cam into a drawing on the computer screen-

http://pastie.org/795453

It needs a plugin to be added to processing, from the JMyron site

http://webcamxtra.sourceforge.net/download.shtml

We were thinking that we should be able to tweak this to drive some
stepper motors, at least i hope my friend will be able to. Trouble is he
has little experience of stepper motors. The motors I have are like the
ones here-

http://www.xylotex.com/StepperMotor.htm

I am unsure of how to realize this within processing in a way that will communicate with the motors successfully

Any advice you have would be greatly appreciated.

Thanks for your time.

4

I always thought the below was most interesting.

5

zoomkat - that is brilliant, delightful, beautiful, wonderful

It is a huge wooden DLP, like TI make for projectors.

GB

6

It is a huge wooden DLP, like TI make for projectors.

The really interesting part is that the wooden mirror has been around for a number of years, probably still more advanced than some current cam/servo projects. Also the shape and color of the mirror pieces along with the lighting to get the proper shading is seriously in the art department.

7

Could you point out which motor controller you've got:
http://www.xylotex.com/Econo4AxSpecial.htm
http://www.xylotex.com/Econo3AxSpecial.htm

or something else?

Both of these seem to take a lot of input signals, and not just two.

GB