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Topic: Wah Pedal Controlled by an Accelorometer (Read 2917 times) previous topic - next topic


I am working on a project that involves a Crybaby Classic Wah Pedal, and my plan is to switch the potentiometer which controls the frequency change, to an accelerometer so that a person can move the neck of the guitar and the Wah effect will be heard. I am unsure how to write the code for this. I have a three axis accelerometer and there are 3 pins on the pedal, which are controlled by the potentiometer at this moment. One is a GND pin and the other two effect the frequency because when these two are connected the high end frequency is produced (think Jimmy Page tone from Whole Lot of Love solo, its very bright and metally.) When neither are connected, the tone remains in the low end. I was wondering if there was anyone out there who had maybe tried this before or had an idea. I can provide more info if this isn't enough. Thanks


Hi, The original potentiometer's 3 terminals are Ground, (some voltage) and the moveable wiper that outputs a voltage between Ground (0.0V) and the (some voltage). 

First use a multimeter to measure the voltage from ground to other end of the potentiometer. You need to know what your are dealing with.

Second with the unit powered off and the pedal in the mid position, measure the resistance across the potentiometer.

IF the voltage is 5 volts (not too likely) you could probably drive it directly from Arduino with PWM and a low-pass filter.

IF the voltage is something else like 12V or 15V etc. you will have to use some transistor / FET device to interface with.

Schematic diagrams for many pedals and effects are on the web. Have you searched??

Accelerometer: Interesting idea.  Which do you have??

Regards, Terry King terry@yourduino.com  - Check great prices, devices and Arduino-related boards at http://YourDuino.com
HOW-TO: http://ArduinoInfo.Info


Worst case scenario, you could pull the pedal off, and connect a servo to the pot and have it rotate it. It would be a much slower effect though unless you got a really good, fast servo.

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