Midi schematic examples and articles - with emphasis on 6n138 and MIDI Input - original title: Gpio midi in

Hardware
1

Hi.I made gpio midi in circuit with 6n138gpio_midiin_circuit
and…no work.Any sugestion ? Tks

2

Well this isn’t much of a suggestion, but I did find a SparkFun midi shield that used a 6n138 and the schematic differs in a couple-few ways:

So I thought that might help you.

Differences I noticed were use of Zener diode not ‘regular’, no 40K resistor, much smaller 220 ohm instead of 4K ‘pullup’ resistor.

I wanted to find the Zynthian schematic as a pdf but couldn’t, and don’t know if it uses a 6n138 anyway.

Here’s an interesting thread on midi circuits:

And another

Can you provide a bit more info on what it is doing to make you say ‘no work’?

1 Like
3

Thanks for the reply. It works perfectly. My synthesizer was the problem. … settings for midi out

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