Guitar signal into an Arduino pin?!

Hello. I need to process my electric guitar with Arduino. What is the simplest way to get a readable signal from the electric guitar (0-5v) into an Arduino pin?

Thanks.

There is a device made specifically to do this, it is called a guitar amplifier. You can use the line out to capture your signal. You will probably have to add an op amp to get the gain where you need it. Side benefit you could hear it with the speaker it drives. You could then use one of the analog to digital pins to convert it to digital where the Arduino can process the data.

You can increase the analog input sensitivity by choosing the 1.1V reference and DC biasing the input to half of that.

The guitar amp line output is a good idea, but if you still want to use the amp to play through, you would need an "effects loop" input and output, some amps do have them.

Don't tell me, you haven't done any internet research on this. What did you find out? There is even a fairly recent thread about it on this forum, you could use the search box to find it.

You probably won't get 5V peak-to-peak but you may be able to get-by with just a bias circuit. (The signal needs to be biased because the Arduino can't read the negative-half of the AC audio signal.)

There is a schematic for a line-level signal in this post. A guitar wants to see a higher impedance so a pair of 2M resistors would be just-about perfect (for a 1M load). With the higher impedance you can get away with a proportionally smaller capacitor value.

Or... You can program the optional 1.1V reference for about 5 times as much sensitivity. Then you'll need a bias of about 0.55V. You can find calculate a voltage divider with a smaller "bottom" resistor of 1M and about 8.1M for the "top" resistor. (You may not find an exact 8.1M resistor).

Note that the raw readings will "look random". You are sampling a continuously-changing waveform that's positive half the of time, negative half of the time, and with two zero-crossings per cycle.

If the signal is not strong enough for the voltage divider, Google for Tillman fet preamp. This simple lowpart count should increase your signal strength for line signal and it do not color your tone.

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