kolorka Posted November 2, 2005 Report Share Posted November 2, 2005 I have my core module connected directly to Gameport as suggested here : http://www.ucapps.de/mbhp/mbhp_midi_gameport.gif My core behaved normally, sent sysex requests for upload, but i did not manage to get MIDI IN working. Core passed all MIDI debugging tests, so I turned to PC-side. Tried new drivers for soundcard , flashed bios ( poor realtek AC97 onboard soundcard), considered cabling and grounding issues. Nothing helped. Loopback test worked only if I connected Rx and Tx directly on Gameport with 470R resistor , but not with short-circuited Rx Tx pin of PIC-socket (got only corrupted MIDI data) After 2 day long debugging i tried to disconnect R6 and everything worked perfectly. Dont know about logic levels of MIDI , but It seems to me , MIDI IN can not work (J11/Gameport connection) with parallel Tx(Gameport) and R6(+5V) on Rx pin of PIC.What do you think ?anyway , thanx for great project Thorsten Quote Link to comment Share on other sites More sharing options...
TK. Posted November 3, 2005 Report Share Posted November 3, 2005 Hi Knuf,thanks a lot for this input! It seems, that the output impedance of your PC gameport is so high, that the Rx signal level doesn't reach the required TTL low level. I've modified mbhp_midi_gameport.gif (propably you have to push the reload button of your browser to see the change). It's now recommented to remove this resistor, or to replace it by 100k to ensure that MIDI In doesn't get invalid data if the core is not connected to the gameportBest Regards, Thorsten. Quote Link to comment Share on other sites More sharing options...
kolorka Posted November 4, 2005 Author Report Share Posted November 4, 2005 Great! I hope this will help to avoid troubles with MIDI IN for bastlers with lame Gameport.bye Quote Link to comment Share on other sites More sharing options...
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