Guitar Note Detection With Shift Register

[Arjuna_1000]

I am working on a guitar note detection project with Arduino.

It works by sending output HIGH to the frets one fret at a time and then for each fret that is HIGH, loop through the 6 string inputs and check if it is HIGH.

It works fine as long as only one fret is touching one string. But if an input-string touches two outputs (two guitar frets), it reads LOW always (it is touching two outputs, but actually only one of them is high at a time). Is the voltage somehow being lost when this happens, or what is happening? If I figure that out maybe I can think of a workaround.

Thanks!

 

[ChrisP58]

Because the outputs of the 595 that are not high are low. So a string touching two frets is shorting a high to a low, and the low is winning.

Place a diode (1N4148 or similar) in series between each output of the 595 and the frets. The anode end connects to the 595.

 

[Arjuna_1000]

Because the outputs of the 595 that are not high are low. So a string touching two frets is shorting a high to a low, and the low is winning.

Place a diode (1N4148 or similar) in series between each output of the 595 and the frets. The anode end connects to the 595.

Thanks a lot! That is what I needed to know!

 

[Pommie]

If you get rid of the shift register and use Arduino outputs then you can switch non high outputs to input.

Mike.

 

[Arjuna_1000]

Ah! Great idea. I'll need to switch to a board with a lot more pins, but that solves it!