If you are a music composer, or just use your PC to record your musical instrument, you know how useful a MIDI controller can be in order to change certain parameters on the fly. Let’s see how to build one at home with potentiometers, buttons and an Arduino.
To use an Arduino as a MIDI controller you need a microcontroller with a native USB interface such as the ATMEGA32U4 present on Arduino Micro and Leonardo. It is also possible to do it using an Arduino Uno by modifying the firmware of the chip that deals with the USB-Serial conversion but the procedure is much more complicated.
Four 10k rotary potentiometers were used, another 4 sliding and 4 buttons.