Need help modifying treadmill.

[Mipoleon]

This is my first time trying any kind of circuitry so I am very much a novice but here is what I am trying to do. I am rewiring my treadmill into a computer keyboard so that when someone moves on the treadmill hit hits the move key on the keyboard for a video game that I play.

Here is what I have so far.

I have a switched that is triggered by a magnet on the conveyor part of the tread mill so that with ever rotation it triggers the switch. The switch is wired into the keyboard so that it closes the circut to the specified key sending a key pressed signal to the computer.

Here is my problem.

Since it sends the signal each time the magnet passes the character in the game moves ackwardly. I put a few more magnets on the conveyor part which seemed to help but if the convey stops in front of the switch the character keeps running. So what I think I need is to some how wire it so that it sends a continual signal to the computer as long as the magnetic switch is being tripped. (As long as the conveyor is moving.) And stops sending the signal when they conveyor stops.

Any help would be greatly appreciated.

 

[Mipoleon]

Does any one have any kind of suggestion at all for me?

 

[mneary]

Turn off "auto repeat" on your keyboard.

 

[Roff]

Does any one have any kind of suggestion at all for me?

I think the solution may be simple, but your description is not clear. Have someone you know read it and see if they can point out the confusing parts (or maybe it's just me).

 

[Mipoleon]

It probably is confusing but here is what I want in the end.

I would like to wire my manual treadmill to my keyboard so that when someone walks on the treadmill it acts as if someone pressed the forward key on the keyboard.

I have figured out how to wire it to the keyboard. But I dont know how to make it so that when someone walks on the tread mill the circuit stays closed until they stop walking. So basically I want to wire it so that as long as the treadmill is rotating the keyboard acts as if the button is being pushed and when the treadmill stops the keyboard stops pushing the button.

I hope that is clearer.

 

[dch222]

You need a monostable (eg555) between the treadmill and keyboard with a period longer than the longest time between two successive pulses from the treadmill when it is running at its slowest normal speed.

 

[Mipoleon]

Thanks, where do I get one of those and how do I go about installinga and configuring it?

 

[House0Fwax]

Google '555 tutorial' and look at the 'monostable' section. It should have everything you need. If you don't understand it, come back and ask.

 

[Mipoleon]

Ok, from what I have read I need to build this:

**broken link removed**

From what I gather Time = Resistor x Capacitor.

Assuming I am correct in the above, I am not sure how to determine the voltage ect. of the keyboard in order to know what kind of resistor to get. What should I do?

 

[Roff]

OK, here's a schematic. It should keep the relay activated so long as the treadmill makes a complete cycle in less than 11 seconds (nominally). The actual time will be a function of component tolerances.
You can use a 12 volt wall wart for power. A 9 volt one would probably also work.

 

[Mipoleon]

Thank you very much Ron for that schematic. It would have taken me forever to figure all that out.

I wonder if I could bother you for one more favor. I just measured the rotation on the treadmill. At the slowest speed it completes 4 rotations per second. Would you be able to tell me what the numbers on the components would have to be to keep the signal going as long as the user completes a rotation within .25 seconds?

 

[Roff]

Thank you very much Ron for that schematic. It would have taken me forever to figure all that out.

I wonder if I could bother you for one more favor. I just measured the rotation on the treadmill. At the slowest speed it completes 4 rotations per second. Would you be able to tell me what the numbers on the components would have to be to keep the signal going as long as the user completes a rotation within .25 seconds?

Change C1 to 220nF (0.22uF).

 

[Mipoleon]

Is that all?

 

[Roff]

Is that all?

You could add some little jingle bells and an incense burner.

Yep, that's all.

 

[Mipoleon]

Do the down arrows represent ground or -12V?

 

[Roff]

Do the down arrows represent ground or -12V?

The little arrows do represent ground. Ground does not mean Earth ground. It's just a way of indicating a common node that is the reference (zero volt) point for all other nodes in the circuit.
Connect the negative terminal of your power supply (or battery, if you use one instead) to ground.

 

[Mipoleon]

I found a .22 uF capacitor when I went to the store. It is a polyester film one as opposed to an electrolytic one which is what I think C1 was originally supposed to be. Will this capacitor work?

 

[mneary]

Yes, almost any capacitor type will work here.

 

[Mipoleon]

Ok, I soldered everything together according to the instructions as far as I know. When I plug the device in nothing happens and the battery gets HOT. I am not sure where I am going wrong. All of the +12V should be wired together to the + on the batttery and the triangles should be wired to the - on the battery correct?

 

[Mipoleon]

I think i found my wiring problem. Now the voltage is being sent to the relay but the switch inside the relay doesnt seem to be closing. Is it possible that I may have damaged something?