Arduino USB Midi Interface

1 x MIDI IN    1 x MIDI OUT   1 x USB

ProMicro USB to MIDI Interface PCB

Appears as MIDI interface on PC Mac Linux Android
Fully programmable using Arduino IDE
Comes pre-programmed so works straight away
Ideal for embedding in your project

PCB works with 6N138
Header pins long enough to plug into you own project
(ver3) PCB available seprately as a kit or make your own--> PDF

Expand to create your own controller
Every analogue and digital pin free to use

Media Library

Pro Micro USB to MIDI Interface Built with PCB
Circuit Diagram
5v MIDI IN Circuit Diagram
MIDI Circuit Assembled close UP
5v MIDI IN Circuit breadboard
5v MIDI IN Circuit breadboard
What's in the Kit

1 x Arduino Pro-Micro 5v - PDF
1 x PCB
1 x 6N138 Opto Isolator - PDF
1 x 1n4148 Signal Diode
3 x 220 Ohm Resistors (red red black)
1 x 10k Resistor (brown black orange)
1 x 470 Ohm Resitor (yellow violet brown)
2 x 3.5mm Stereo Jack sockets
2 x 5 Pin DIN Chassis sockets + wire    


Software & Libraries
Arduino IDE

Control Surface - GitHub

Pre-loaded Arduino Sketch

Test the MIDI in

Printed Circuit Board
PCB Artwork - Works Single Sided Etch
ZIP - PDF Normal - PDF Mirrored
Circuit Diagram & breadboard layout

ATmega32U4 Datasheet PDF

5v 3.3v controller 6N138 Confusion LINK

Other Reading
(because we're standing on the shoulders of giants)
... -Click
... -WWW Link
Stuff you need

Hand Tools
1 x Soldering Iron & Solder
1 x Side Cutters

Other Stuff
MIDI Cable
MIDI Instrument or controller
Computer with USB socket and Internet Access

Be Careful
Music equipment is expensive.
Check your work against the pictures.
You can't really go wrong.
But it is your responsibility   :-)
Assembly Instructions

Smallest parts first  
Diode - must go in this way round    Diode goes in this way round
Resistors - check the colour code
6n138 - must go in this way round
Round dot next to square pad
6N138 close up

Solder header sockets to PCB  
This depends on how you want to use the board.
If you want to expand and add or remove the ProMicro later solder these sockets -
If you want it small and non removable just solder the header pins ready to receive proMicro - IMAGE

Solder sockets  
3.5mm Stereo Jacks
5 Pin Din Sockets

Solder headers to PCB  

Check your work before you power it up.  
1 - Check soldering with maginfine glass
2 - Make sure orientation of components matches photos
3 - Connect the USB socket to a computer