How could I detect when a guitar string is played?

[Guest]

I had an idea for my uno, which is putting six leds on the bridge of my guitar and lighting them up when the corresponding string is played. I'm not really sure how I could detect that though. Any ideas? I don't think a light sensor would work because there would be a lot of interference, some kind of microphone would probably detect the other strings as well.

[swordsman247]

Maybe some kind of magnetic sensor?

[reddemonoverlord]

4 minutes ago, whitephoenix said:

I had an idea for my uno, which is putting six leds on the bridge of my guitar and lighting them up when the corresponding string is played. I'm not really sure how I could detect that though. Any ideas? I don't think a light sensor would work because there would be a lot of interference, some kind of microphone would probably detect the other strings as well.

Well, you could use your computer if you had a way to imput the sound.

[DonDeWaay]

Makey makey? You can complete a circuit by touching the string and you can set up a function. I don't know how to connect it to LEDs, though. Hopefully this helps.

[DonDeWaay]

Just now, DonDeWaay said:

Makey makey? You can complete a circuit by touching the string and you can set up a function. I don't know how to connect it to LEDs, though. Hopefully this helps.

Oh also there's a LTT and Channel Superfun video on it.

[Guest]

1 minute ago, DonDeWaay said:

Makey makey? You can complete a circuit by touching the string and you can set up a function. I don't know how to connect it to LEDs, though. Hopefully this helps.

I don't want to buy one if possible. Maybe I could rig up something similar though.

2 minutes ago, reddemonoverlord said:

Well, you could use your computer if you had a way to imput the sound.

If possible I'd like to avoid adding any non-portable components to this

[bob345]

i would say a capacitive sensor attached to the strings, but most guitars i know of use a metal bridge which would make pretty much any capacitive or voltage based circuit only see all the strings as one. If each string is electrically isolated, then a capacitive touch system should work great. That along with a microphone so that the strings being touched will only light up when where is sound.

[kasugatei]

I would like to know is it electric or acoustic guitar.

In case of electric one, capacitive sensor(s) would have lots of issues because all strings are connected to a common ground (bridge). Touch one string, all will lit up. In that case piezo under each string should be much better idea. Then you can use analog inputs of your uno to light up a LED if there is certain threshold reached (voltage from piezo).

For acoustic one, capacitive sensor should be the easiest solution since all strings are insulated from each other BUT the LEDs would lit up even if you just touch any of the strings. Installing piezo for each string separately is not easy at all (usually there is a piezo underneath saddle in electro-acoustic ones).

For classical guitar is really difficult situation because 3 strings are conductive and 3 are not (nylon) and there is again problem in installing separate piezo for each string separately.

 

There is also another way (in theory at least) to use mic and FFT algorithm to distinguish which strings are played but it would probably take you months to program that