Description
Fun little project kit to build your own little MIDI Keyboard. Basic PCB soldering skills required.
Specifications
- MIDI Out – Connect to your MIDI synth, keyboard or computer.
- MIDI In – Play music notes through the in-built piezo buzzer.
- Pitch Control.
- Powered by 5v USB.
- Pressing two buttons at one (i.e C & D keys) will play the sharp notes (i.e C#).
- Measurements: 128.5mm x 50.5mm x 23mm (Eurorack 10HP).
Build Instructions
Designator | Name | Quantity | |
---|---|---|---|
Designator | Name | Quantity | |
CSTL | 16MHZ | Crystal | 1 |
SP1 | PIEZO | Buzzer | 1 |
R7 | 1k | Resistor | 1 |
R5 | 4.7k | Resistor | 1 |
R4, R1, R3, R2, R6, R9 | 220R | Resistors | 6 |
R8 | 10k | Resistor | 1 |
SW1 | A_NOTE | Button | 1 |
SW3 | C_NOTE | Button | 1 |
SW2 | B_NOTE | Button | 1 |
SW4 | D_NOTE | Button | 1 |
SW5 | E_NOTE | Button | 1 |
SW6 | F_NOTE | Button | 1 |
SW7 | G_NOTE | Button | 1 |
SW8 | RESET | Button | 1 |
C2, C1 | 22pf | Capacitors | 2 |
OK1 | 6N138 | Octocoupler | 1 |
POT1 | 10K | Potentiometer | 1 |
U1 | ATMEGA328P-PU | Arduino | 1 |
USB1 | Mini USB-B 5P-Female-TH_C46398 | USB Connector | 1 |
DIN1 | MIDI_IN 5-Pin DIN Connector | DIN Plug | 1 |
DIN2 | MIDI_OUT 5-Pin DIN Connector | DIN Plug | 1 |
D1 | 1N4148 | Diode | 1 |
T1 | BC548B | Transistor | 1 |
SW9 | SWITCH-DPDT (ESwitch EG2211) | Slide Switch | 1 |
LED1 | Green LED | 1 |
Resistors
Board Layout


Arduino Code
The ATMEGA328 is loaded with code from:
https://github.com/jamesleesaunders/arduino_midi
The ‘all_in_one’ sketch.