Midi problems

[Cyril]

I have some midi transfer problems with my Midibox64 (based on the PIC16F).

In the beginning I was using the midi in/out connectors but I had strange midi messages every second when using Cubase (like aftertouch or similar midi messages). Sending sysex to the box was possible but didn't work sometimes resulting in strange letters in the LCD display (I had to restart the box).

So I decided to try the midi-to-com port (I removed the optocoupler and pluged the Max232). Now I have no more strange midi activities (except that Cubase receives only pitchbend and aftertouch messages from the box) but I can't send or request sysex any more. I tested all the drivers but none functions. Another strange things: the green LED remains always lit...

How can I know if it's an hardware problem without reprogramming the PIC with the test firmware (I'm afraid to damage the PIC by removing it from the socket :-[).

[TK.]

Hi Cyril,

when using the MAX232, you've also to enable the to-COM option in the MIDI merger menu, otherwise the baudrate will be wrong. This explains why the box doesn't receive SysEx anymore, and why it sends pitch bender events instead of controller events.

But it's strange that your box sends more or less random data continuously. The root cause must be different. Possible reasons:

• feedback loop (exit Cubase and check the MIDI messages with MIDI-Ox, if the vanished, check your Cubase setup)
  
• missing Pull-Up at the last 74HC165 shift register or DIN input
  
• missing ground connections on unused analog pins
  

Best Regards, Thorsten.

[Cyril]

Thanks you Thorsten, you helped me solve my problems:

First I have enabled the midi-to-com option and... Cubase receives normal midi messages again.

Then I have disabled the midi merger option and sending sysex works great. if only I had read better the Midibox64 tutorial ("If you connect the MIDI In of the MIDIbox with MIDI Out of your computer, you should disable the MIDI merger in order to avoid endless feedback loops")! ::)

I don't know why but with the midi-to-com port I have no more random data. Now everything works great except that I have some problems requesting sysex with VMidibox, but that's no a big problem because I don't really need it the way I use my box.

So now it's time for music!!!  8)

Best Regards