Autonomous USB MIDI interface

[Synthex]

!!! UPDATE 01/02/2008 !!!

Hello Folks,

Here is my autonomous USB MIDI interface.
You can use my MegaDrum firmware with it !
Of course, it can be programmed in LVP !

Synthex USB MIDI Device v2.gif

Synthex USB MIDI Device TOP.pdf.zip

Synthex USB MIDI Device BOTTOM.pdf.zip

MegaDrum USB MIDI Firmware 18F2550 12MHz V2.hex

Regards,
Synthex

[baguette]

As for the PCB, i recommend to look in your layout software for a function to fill the large spaces with copper (connected to ground) - this way you use less chemicals for the etching process.

[Synthex]

As for the PCB, i recommend to look in your layout software for a function to fill the large spaces with copper (connected to ground) - this way you use less chemicals for the etching process.

It is a point of view ...

Here is this version !

[Synthex]

Here is pinouts.

[Marctwo]

This may be a stupid question... but what does the 6N138 do? I see it's connected to the midi ports, is it some kind of midi buffer for the eusart output?

[Synthex]

This may be a stupid question... but what does the 6N138 do? I see it's connected to the midi ports, is it some kind of midi buffer for the eusart output?

Have you seen the 6N138 datasheet ?
It's an "optoisolation", this is the standard Midi.

It is connected to the input and not output.

No buffer, just protection, electrical insulation

[Marctwo]

Have you seen the 6N138 datasheet ?
It's an "optoisolation", this is the standard Midi.

It is connected to the input and not output.

No buffer, just protection, electrical insulation

Sorry, I'm very new to electronics... I did look it up but I haven't got a clue what optoisolation is. I obviously haven't reached that chapter yet.

[Synthex]

Just made a small search on google using as a keyword 6N138.

[Marctwo]

Yes, as I said I did look it up... and I found it... but data sheets generally make sense only when you already understand what the subject is. I also found it on several commerce sites but still couldn't understand it's purpose.

But I'm learning as now I know from you that optoisolation it is to do with 'electrical insulation'.

[Lakedaemon]

I guess that we want to avoid ground loops or other nasty problems of the same kind.

Opto-isolation transfer the information with light without connecting the circuits electrically so that they can live in two separate electrical spaces (with different grounds, etc...)

Actually, the "only" electrical connection of megadrum to the computer is through USB (if you take out the optoisolator circuit of the digital board).