================= d e r n u l l e f f e k t =================


beyond the art by Wolfgang Spahn

midi interface for the Arduino =============================

projector circuit

Here are some midi-in, midi-out and midi-thru-circuits for the Arduino. They are made with the opto isolator 6N138 or the inverter 74LS04N. To prevent bootloading confusion always put another opto isolator between the interface and the arduino. This opto isolator should open after the bootloading process is finished.

This picture is an midi-in (right) and midi-thru (left) circuit:

projector circuit

The midi-in circuit with the 6N138 (thanks to Jeff Mann):

Midi In

The midi-thru circuit. The LED helps to detect the midi-signal. To use it for midi-out just connect it to TXD instead of RXD.

Midi Thru and Out


This is a midi-out (left) and midi-in (right) circuit with an additional opto isolator.

projector circuit

And that is a good working code for the Arduino. It reads a midi-in signal, ignores the original midi-off signsl and sends a delayed midi-off signal.