Pulse on off, to change resistance in circuit

Hi, im a noob.. so here goes.
I going to put a reed switch near a bike wheel. A magnet on the spoke, as every time the wheel goes around it will make the switch turn on and off.
What I want is to make a circuit with Arduino board.
I want to change resistance in a circuit according to how fast the reed switch turns on and off.


Hope this makes sense..

Thanks for any help.

Cheers

Don't use resistance. Use PWM to control the brightness.

Increase the duty cycle when the input pulse timing is shorter. Decrease it when they get longer.

Thanks, but I just used the light as an example. I not using it for a light, but i really do need to change the resistance. Like a variable trim pot.

I wish to change the pitch of audio with variable resistance - changed by the speed of the wheel.

yipyap777 said:

Thanks, but I just used the light as an example. I not using it for a light, but i really do need to change the resistance. Like a variable trim pot.

I wish to change the pitch of audio with variable resistance - changed by the speed of the wheel.

Click to expand...

Then you should use a digital potentiometer. Lots of them out there.

www.maxim-ic.com
www.analog.com
www.microchip.com
www.ti.com

Thanks that's put me on the right track didn't know they existed.