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DIY Stompboxes => Digital & DSP => Topic started by: lukatosh on May 27, 2021, 10:57:28 AM

Title: MIDI Split design
Post by: lukatosh on May 27, 2021, 10:57:28 AM
Hello everyone! I hope you are all ok!

I'm writting from Chile so please excuse any mistake of my english.

I would like to ask you something about splitting a MIDI OUT signal from a microcontroller...  Hope you can help me.

Let's say we are using Rx pin of an arduino to send a "master" MIDI Out signal. I want to split this line to feed multiple pedals that use MIDI viaTRS. What would be the correct way to achieve this? I should make  pass through an optocoupler  and then buffer and "plit"? (A) or I just need to buffer inmediatly after Rx pin (and resistor) (B)?.

If you could explain me the pros and cons or maybe the technical justification of each method i''ll pleased to learn.

Thanks so much!! Stay safe!

(https://i.postimg.cc/SjkT7Pwg/midi-split.png) (https://postimg.cc/SjkT7Pwg)
Title: Re: MIDI Split design
Post by: FiveseveN on May 27, 2021, 12:17:45 PM
Rx means receive, what you want is the Tx pin.
In the MIDI standard, the optocoupler isolation happens at the input of each device, you don't need one at the output(s).
So option B but from Tx.
Title: Re: MIDI Split design
Post by: lukatosh on May 27, 2021, 12:33:27 PM
Ohh... what a mistake  :o .... You are right. It's Tx.  Thanks!!

Title: Re: MIDI Split design
Post by: ElectricDruid on May 27, 2021, 04:04:00 PM
+1 what FiveSeven said. Option B is exactly it, except from Tx.
Title: Re: MIDI Split design
Post by: potul on May 28, 2021, 04:40:46 AM
Option B looks fine.

Resistor R1 is probably not needed though.