Adding Standard LEDs inline on a controller

If you don't want to use APA102s, and just want to hook up normal LEDs from buttons, you can follow the following guide.

Supplies

  • A controller modded using any of the guides
  • Some LEDs
  • The correct current limiting resistor for your specific LEDs

The finished product

Finished adaptor

Schematic

Schematic

Note that you can use whatever pins you want as your digital pins, this is just for example And node that the 220ohm resistor value is also for demonstration, you will need to calculate the correct resistor for your specific LEDs. Usually LEDs will have a recommended resistor in their datasheets, but there are also calculators online.

Steps

  1. Hook all the anodes of the LEDs to the 5V pin on your microcontroller (note that for the pi pico, this is VBUS).

  2. Hook up the cathodes of the LEDs to one side of each fret

  3. Hook the other side of the fret up to a digital pin on your microcontroller

  4. Hook up the resistor in parallel between each digital pin and ground. You should have two connections to each digital pin, one going to the fret, and one going to a resistor that then goes to ground.

  5. If you would like to also respond to game events, such as star power in YARG, you can wire seperate LEDs to digital pins on the microcontroller. Instead of connecting this in parallel, put the LED and resistor in series. You should end up with the pin on the microcontroller going to a resistor, then the LED and then ground. This is also how you would set up things like Player LEDs. For star power, you need to hook up the LED to a pin that supports analog outputs, which can be found in the following table:

    Microcontroller Analog Output Pins
    Pi Pico (Recommended) Any
    Pro Micro, Leonardo, Micro 3, 5, 6, 9, 10, 11, 13
    Uno 3, 5, 6, 9, 10
    Mega 2 - 13, 44 - 46

Programming

  1. Click on the button in question
  2. Make sure the input type is set to Digital Pin Input
  3. Make sure Pin Mode is set to Pull Up.
  4. Hit Find Pin
  5. Press the button on your controller
  6. Turn on Invert. Due to how we wire LEDs, the input needs to be inverted to work correctly.
  7. If you want to react to game events in supported games, you can hit the Add Setting button and add a LED Binding.
  8. Then turn on Enable Digital Output and set the Digital Output Pin to the pin you have configured.
  9. The star power LED instead requires turning on Enable Analog Output and setting the Analog Output Pin.