Having built a stand-alone PC USB to Arduino Serial MIDI link, I thought it might also be useful to have a shield that allows a direct PC USB link to the Arduino too.
Warning! I strongly recommend using an old or second hand keyboard for your MIDI experiments. I am not responsible for any damage to expensive instruments or computers!
Once again the key Arduino tutorials for the main concepts used in this project are:
If you are new to Arduino, see the Getting Started pages.
Parts list
- Arduino Pro Micro
- Arduino Uno “Proto Shield”
- An existing Arduino MIDI project for testing
The Circuit
This project takes an Arduino Pro Micro (3.3V 8MHz) and mounts it onto a protoshield as shown below. The Pro Micro is another Arduino Leonardo variant using the ATmega32U4, so it can act as a USB MIDI device to a computer.
In my case I added a switch between the Pro Micro’s TX and the Arduino Uno’s RX pins and I added a jumper in the 5V link so that I have a choice to extend the power from the Pro Micro’s micro USB link to the Arudino’s 5V line or keep the two boards powered independently.
If the Arduino Uno is being powered independently then I’d recommend removing the jumper and letting the USB link power the Pro Micro on its own.
As this is using the 3V Pro Micro, the serial port signaling levels will be 3V too – but it is typically to connect a 3V transmit to a 5V receive, but not the other way round.
If you have a 5V variant of the Pro Micro then you might need to hook up the power lines slightly differently and be sure to set the build options for the correct clock speed.
The Code
This uses exactly the same code as for the PC USB to Arduino Serial MIDI but this time built for the Sparkfun Arduino Pro Micro 3.3V 8MHz.
Closing Thoughts
Great – that is a couple of more ways to getting MIDI signals into my Arduino projects. I’ve now updated the Arduino MIDI Interfaces page to list them all.
Kevin
Simple DIY Electronic Music Projects 