ScratchWheel sensing technique

[LowRunneR]

hi guys

First I have to say, i am from Austria and my English is not the best...

Ok i want to make something like the tractorizer or the Behringer BCD3000, a MIDI DJ Control board to control virtual DJ. But i want to make it myself with an AVR an some I/O Expanders, this is not the problem, but the scratch wheel.

The technique from MTE of the tractorizer scratch wheels seems a bit tricky for me, because you have to connect the encoder and the HDD plate with a belt. I thought of something easier, like to roll the HDD plate on a mouse wheel with its encoder an use this signal to get the rotation. I think this is much easier to make.

Optical measurement is also hard to do, because you need a encoderwheel and sensors.

What do you think about this idea? Would be great if we could discuss the Pros and Cons of some ideas.

Best Regards

LowRunneR

[lylehaze]

hi guys

First I have to say, i am from Austria and my English is not the best...

Ok i want to make something like the tractorizer or the Behringer BCD3000, a MIDI DJ Control board to control virtual DJ. But i want to make it myself with an AVR an some I/O Expanders, this is not the problem, but the scratch wheel.

The technique from MTE of the tractorizer scratch wheels seems a bit tricky for me, because you have to connect the encoder and the HDD plate with a belt. I thought of something easier, like to roll the HDD plate on a mouse wheel with its encoder an use this signal to get the rotation. I think this is much easier to make.

Optical measurement is also hard to do, because you need a encoderwheel and sensors.

What do you think about this idea? Would be great if we could discuss the Pros and Cons of some ideas.

Best Regards

LowRunneR

Welcome.

From the programming side, both the methods you describe are encoders, so not much difference in the code.

MIOS offers a variety of encoder settings, you can try each one and see what works best for your needs.

I would _think_ that you'd get higher repeatability with a belt-driven encoder than with a mouse wheel. If I

move my mouse up and down five times, there is little chance that the mouse pointer will be in the same place as it was before I started. A belt-driven encoder would probably be more repeatable than a friction driven mouse ball.

If you could find a direct encoder that is suitable, that would trump all. I have one here that came home from work, but it's probably too expensive for most people to consider.

You'll probably find most of the conversation here centers around the MIOS operating systems, and most of the projects here are based on one of the two MIOS platforms. If you'd like to know more, you can click on the uCApps link above to learn more about it!

The "User Projects" part of the forums is usually used for completed MIOS projects that are ready for sharing with the public. A better place for this topic might be "Design Concepts" or "Parts Questions". There is a post at the top of "User Projects" that describes the criteria for posting in this forum.

Have Fun,

LyleHaze

Edited November 2, 2009 by lylehaze

[nILS]

Please read: before posting in User Projects.

[LowRunneR]

I would _think_ that you'd get higher repeatability with a belt-driven encoder than with a mouse wheel. If I

move my mouse up and down five times, there is little chance that the mouse pointer will be in the same place as it was before I started. A belt-driven encoder would probably be more repeatable than a friction driven mouse ball.

Thanks for you reply, but i will not use the mouse ball, but the mouse wheel or scroll wheel. And it doesnt matter if it is not so repeatable, because i only have to know if the jogwheel is moved cw or ccw. I have to check the output high low levels from the opto encoder of the wheel.

so long

Low