two optocoupler circuits?

MIDIbox HUIs
1

I’m building a MB64 controller for a synth. The synth is controlled with a Teensy ( similar to arduino) ATmega 32U4

I’m sending MIDI from my sequencer to the MB64 that merges the notes from the sequencer and the CC data from the pots connected to the Core

My question:

Do I need another optocoupler circuit between the Core and the Teensy?

Or can just connect the PIC’s TX to the Teensy RX? They are both powered by the same 5V circuit

 

It just seams a bit “overkill” with the MIDI OUT resistors + MIDI IN circuit between them when they are powered by the same source.

2

Within the same system you do not need another opto coupler.

3

thanks nILS

 

I thought I had read that somewhere, but I needed to get it confirmed by a Guru :slight_smile:

4

What about the 220 ohm resistor between pic’s TX and MIDI OUT?

5

is to protect the TX circuits from inside of  uC  …