Chico,

Your bit-rate initialization is correct as i read it. A final verification would be using an o'scope to validate the PC and Micro bit widths are similar.

You report that the problem isn't solved but surely it is changing its symptoms?

For example your original problem had significant delay between input and output didn't this change when you coded the pass thru?

I think if you can isolate the symptoms you will solve this problem. An example of a simple test would be code your project to not recieve MIDI but to just issue Note On/Off messages. If you could ensure a debounce, you could toggle a micro pin ... when low issue a canned NOTE ON msg, when hi it's companion NOTE OFF. Another method would be to just make a slow timing loop and alternately issue Note ON and Note OFF messages to your recieving MIDI sound device (the PC i believe?).

With this kind of rig you would validate the ability to issue hardwired (guaranteed logical msg integrity) messages to the MIDI reciever.

With the MIDI tx integrity known you could confidently proceed to recieve message testing.

Are you using MIDI-OX?? This utility is wonderful for displaying tx/rx MIDI and providing filtering so you can gently test your interface across the many conditions and message types inherent in MIDI exchange.

regards,
p