Friday 2 December 2022

Build a Programmable USB Midi Controller - FADR-4


The FADR-4 is a programmable - four fader - USB Midi Controller. It uses 100mm faders for precise control and a quick one button and LED interface for changing Midi CC numbers. Check out this video to learn how to build one! VIDEO

Download the code and schematics at my Github page HERE

PARTS LIST (with Amazon Associate Links)

1 - Teensy LC Microcontroller

1 - 74AHCT125 Quad Buffer

1 - MAX7219 LED Driver

1 - Three Digit LED Display - Common Cathode

2 - 0.1 MicroFarad Capacitors

1 - 33K Ohm Resistor - 1/4 Watt

1 - Panel Mount USB Adaptor cable (Micro to USB B)

1 - Push Button - Momentary - Normally Open

4 - 10k Ohm (Linear Taper) Potentiometers - Can be Faders or Turn Pots

(I used ALPS RSA0N1119A02)


  1. You’re doing a remarkable process. Hold it up

  2. any way to make it a 10 fader panel? of do i have to work with 3 teensy?

  3. Isn't it a bit overkill to use a teensy for four adcs, a button and an i2c/serial bus?
    I would probably opt for an atmega328 on vero, if there's space for it. It would cut a lot the price, and you don't really lose anything. The 328 has 10 bit adc compared to the teensy's 12 bit, but you're truncating it to 7 bits anyway, so you won't get to see much of the noise either way, provided you have a clean vref.

  4. Hi, I want to built with Arduino Pro Micro or Teensy 2.0?

  5. Hi there,
    Can FADR-4 code for with Teensy LC be also used with Teensy 4.0 or same will need to be adjusted/modified.
    Thanks in advance

  6. Great project! Thanks for the tutorial!