midi in not workin (but midi out is)

[Guest kejace]

Hi everybody.. this was posted when the forum wasn't working so I try again.

I got very happy when I got my first "F0 00 00 7E 40 00 01 F7" from the bootloader! But then I seem to have problems with midi in because I cannot upload MIOS.

I've checked all the posts about this problem but nothing suggested there works for me.

I've have the settings in MIDI-OX suggested by Sephult in http://www.midibox.org/cgi-bin/yabb/YaBB.cgi?board=troubleshooting;action=display;num=1059029739 but still the same results (I get the "F0 00 00 7E 40 00 01 F7" every two seconds.)

So I try to check the midi in as suggested by Thorsten in http://ucapps.digitaljunk.org/cgi-bin/yabb/YaBB.cgi?board=troubleshooting;action=display;num=1055726526 and I have some questions:

First of all isn't it the long pin of the LED that should be connected to Vss? That is what makes my LED light up but I just want to make sure.

Second, when I connect the LED between RX and Vss the LED lights up but it doesn't flicker when I send midi in so the test fails. When I do the second thest (LED between pins on J13) the LED flickers on midi in.

Does this mean that the optocoupler is damaged?

thanks in advance..

[Guest SK12]

Hi,

same here(except for your first question), already exchanged the optocoupler. But it didnt´t changed anything.

There also some tips on the How to debug page(link is on the Midibox 64 Tutorial page).

[TK.]

Hi,

First of all isn't it the long pin of the LED that should be connected to Vss? That is what makes my LED light up but I just want to make sure.

This is strange - it would mean that there is a negative voltage between Vss and Rx, but under normal circumstances this should never happen. Did you also check the connections based on the schematic?

http://www.ucapps.de/mbhp/mbhp_core.pdf

The most frequently reasons for MIDI In problems are:

• bad solderings or junctions
  
• exchanged wires at the MIDI In jack
  
• non-functional MIDI Interface at the other side
  
• misconfigured MIDI software
  

(the last two points aren't your problem)

It isn't so easy to ensure that the optocoupler hasn't been damaged, maybe you should check the Rx port with a direct connection to the PC:

Best Regards, Thorsten.