Create leds for guitar fretboard

Hello all, I am new here and also new with Arduino, however I have programmed before so I know the basics of programming.

I would like to create something like Fret Zealot myself. It surprises me that I havent found someone on this forum who tried the same before?

Anyway I wish for 102 leds (17 frets x 6) but would be happy with less also and they need to be very small (because they need to stay below the fret) and I want to use: 0.1Mm Wired Chip Led Smd 0402 3V (really small!!)

These leds are not individually addressable and I don't have 102 digital outlets (I have Arduino One). I need them to be individually addressable though. The leds only need to go on and off based on a pattern and this pattern should be able to shift.

What would be the best way to go? I've read something about shift registers and charlieplexing n*(n-1)?

I could hook up 36 leds on 6 pins (and maybe repeat that, though I would need Arduino Mega I guess)

What would be the best (and most easiest) approach? thanks!

If you are not dimming you can use cascaded shift registers to address an almost unlimited number of LEDs, using 3 Arduino output-pins. Or there are similar special-purpose LED driver chips. I've use six MAX6968 chips to control 48 LEDs. (There is a similar 16-output chip.)

1 Like

Read up on multiplexing.

With 6 leds per fret, you’re almost ideally set to use a byte wide(8) bit matrix.
6 wires (columns) that run the length of the neck, and another 17 ‘rows’…one for each fret.

Then using one of several methods e.g. max7219 or other chip to scan those rows & columns.

You generate clock and data across a small number of pins to ‘scan’ and update the whole array of LEDS as frequently as you want.

This isn’t a beginner project - so your first task is to find a programming buddy to help you develop the patterns, timing & mapping of them onto the array, while you drill holes in the guitar. You can learn on the way.

1 Like

Thanks!! I will check it out

Thanks, yes I need to learn a lot, that is why I am happy there is so much help here, thanks!

I don't intend to drill though, I want to make a sticky tape with these smd leds (just like Fret Zealot)

Just forget "Charlieplexing". It has its uses, but not for you! :roll_eyes:

You need a MAX7219 module.

Two of them actually for 102 LEDs.

Buy the unassembled modules.

Ignore the supplied matrix and its pin sockets; wire your LEDs in two matrices (much easier than one wire per LED anyway!) and wire them to the modules.

1 Like

Thanks for the advice, will check it out!