11. March 2014 1
Choosing the right optocoppler for your midi-in project (e.g. Arduino)
The headlines almost says it all: when building an midi-input device for an µC-project e.g. an Arduino or an Raspberry Pi project, the first thing the MIDI cable “sees” is the optocoupler. And is important to choose the right one.
A lot of ciruits relate to the “4N28”. This is a passive optocoupler and to be frank it causes a lot of problems in the standard setup which mostly are not identified as an electrical problem.
- no midi input at all
- random loss of midi notes
- random playing of other midi notes