Pro Micro Buttons and Pots: USB MIDI Build | ShillehTek

May 27, 2026 15 views

Project

Build a Pro Micro USB MIDI controller with buttons and potentiometers that your DAW detects instantly, using MIDIUSB for notes and CC control from ShillehTek.

3 hr Intermediate3 parts

Project Overview

Pro Micro USB MIDI Controller: Use a Pro Micro (ATmega32U4) with buttons and 10kΩ potentiometers to create a USB MIDI device that sends notes and control changes to any DAW.

The ATmega32U4 has native USB, so it can identify as a class-compliant MIDI controller. After wiring the inputs and flashing a MIDIUSB sketch, you plug it into your computer and map the buttons and knobs in Ableton, FL Studio, Logic, or any other DAW.

Time: ~3 hours
Skill level: Intermediate
What you will build: A USB MIDI controller with 8 buttons and 4 knobs that your DAW recognizes natively.

Pro Micro ATmega32U4 DIY USB MIDI controller with buttons and potentiometers mounted in a small enclosure — Pro Micro + buttons + pots + housing = a real USB MIDI controller.

Parts List

From ShillehTek

Pro Micro ATmega32U4 - the microcontroller board that appears to your computer as a USB MIDI device.
200pcs Tactile Button Switches - used for the 8 digital note triggers.
Dupont Jumper Wires - for prototyping and internal wiring between the Pro Micro, buttons, and pots.

External

4× 10kΩ linear potentiometers - for the 4 analog control knobs.
Enclosure (3D-printed or wooden) - to mount the buttons, pots, and board.
USB Micro-B cable - to connect the Pro Micro to your computer.

Note: The Pro Micro is what many commercial MIDI controllers are built around. Same chip, your firmware.

Step-by-Step Guide

Step 1 - Plan the layout

Goal: Decide where the Pro Micro, 8 buttons, and 4 potentiometers will sit before you solder or mount anything.

What to do: Arrange the components in your enclosure (or on your work surface) so the wiring runs are short and the USB port remains accessible.

Pro Micro ATmega32U4, eight tactile buttons, and four potentiometers laid out before soldering for a USB MIDI controller build — Pro Micro + 8 buttons + 4 pots laid out for soldering and mounting.

Expected result: You have a clear physical plan for where parts mount and where wires will route.

Step 2 - Wire the buttons and potentiometers

Goal: Connect the 8 buttons to digital inputs and the 4 knobs to analog inputs so the sketch can read them reliably.

What to do: Wire each button between a Pro Micro digital pin and GND. The code uses INPUT_PULLUP, so the button reads LOW when pressed.

Wire each potentiometer with the wiper (middle pin) to an analog input, and the two outer pins to 5V and GND.

Pro Micro ATmega32U4 wiring diagram showing eight buttons connected to D2 to D9 and four potentiometer wipers connected to A0 to A3 with 5V and GND rails — Each button goes between a digital pin and GND using INPUT_PULLUP.

8 buttons to D2-D9
4 pots: wiper to A0-A3, outer pins to 5V and GND

Expected result: All buttons and knobs are physically connected to the correct pins and share common 5V and GND as needed.

Step 3 - Install the MIDIUSB library

Goal: Add the library that makes the Pro Micro enumerate as a USB MIDI class device.

What to do: In the Arduino IDE, go to Tools → Manage Libraries and install MIDIUSB.

Expected result: Your Arduino environment can compile sketches that use MIDIUSB.h.

Step 4 - Upload the sketch

Goal: Flash firmware that sends MIDI note on/off messages from buttons and MIDI control change (CC) messages from potentiometers.

What to do: Paste the sketch below into the Arduino IDE and upload it to your Pro Micro.

Code:

#include <MIDIUSB.h>
const int BTN_PINS[] = {2, 3, 4, 5, 6, 7, 8, 9};
const int POT_PINS[] = {A0, A1, A2, A3};
bool prev[8];
int lastPot[4];
void noteOn(byte note) {
  midiEventPacket_t e = {0x09, 0x90, note, 100};
  MidiUSB.sendMIDI(e); MidiUSB.flush();
}
void noteOff(byte note) {
  midiEventPacket_t e = {0x08, 0x80, note, 0};
  MidiUSB.sendMIDI(e); MidiUSB.flush();
}
void cc(byte ctl, byte val) {
  midiEventPacket_t e = {0x0B, 0xB0, ctl, val};
  MidiUSB.sendMIDI(e); MidiUSB.flush();
}
void setup() {
  for (int p : BTN_PINS) pinMode(p, INPUT_PULLUP);
}
void loop() {
  for (int i = 0; i < 8; i++) {
    bool now = digitalRead(BTN_PINS[i]) == LOW;
    if (now && !prev[i]) noteOn(60 + i);
    if (!now && prev[i]) noteOff(60 + i);
    prev[i] = now;
  }
  for (int i = 0; i < 4; i++) {
    int v = analogRead(POT_PINS[i]) >> 3;   // 0-127 MIDI range
    if (abs(v - lastPot[i]) > 1) {
      cc(20 + i, v); lastPot[i] = v;
    }
  }
  delay(5);
}

Expected result: When plugged into your computer, the Pro Micro shows up as a USB MIDI device.

Step 5 - Build and assemble the enclosure

Goal: Mount the buttons and pots securely and package the controller for regular use.

What to do: Cut or print a faceplate, mount the buttons and potentiometers, then fix the Pro Micro inside so the USB port is reachable.

3D-printed faceplate with tactile buttons and potentiometers installed for a Pro Micro USB MIDI controller — Faceplate example with buttons and pots mounted cleanly.

Finished Pro Micro USB MIDI controller inside an enclosure connected by a micro USB cable to a computer — Plug into your computer and your DAW will detect a MIDI device.

Expected result: A finished USB MIDI controller you can plug in and map inside your DAW.

Step 6 - Optional upgrades

Goal: Identify straightforward ways to extend the same Pro Micro MIDI controller design.

What to do: If you want to expand beyond the basic build, consider these add-ons:

Add an OLED to display current MIDI mode or preset
Use encoder knobs (KY-040) for relative-value controls
Add banks: hold a shift button to send a second layer of notes/CCs
Add Bluetooth MIDI (HM-10) for wireless connection to iOS GarageBand

Expected result: You have clear next-step ideas without changing the core wiring and sketch approach.

Conclusion

This project turns a Pro Micro (ATmega32U4) plus simple buttons and potentiometers into a class-compliant USB MIDI controller that can drive notes and CCs in your DAW.

Want the exact parts used in this build? Grab them from ShillehTek.com. If you want help customizing this project or building something for your product, check out our IoT consulting services.