jeroddumas Posted June 16, 2003 Report Share Posted June 16, 2003 Just put together a MB core module. The only problem is that I am getting no midi in. I am believing this to be an octocoupler problem. Is there anyway to test the octocoupler? Quote Link to comment Share on other sites More sharing options...
TK. Posted June 16, 2003 Report Share Posted June 16, 2003 yes, there are several ways to test the MIDI In by using a LED.First step:For this test you have to solder two cables to the bottom side of the core module. The LED should lit (take the polarity of the LED into account, the short leg is the cathode and has to be connected via a resistor to Vss). So long as single MIDI events are received, you won't notice a difference, but with a continuous SysEx stream the LED should begin to flicker.Note: so long as the LED is connected directly to the Rx pin, the PIC will *not* receive the MIDI data due to the power consumption of the LED. This method is only usefull to test if the MIDI signal is available at the Rx pin.If the LED doesn't lit, connect the anode to the optocoupler (Pin IC2:6). If it still doesn't lit, connect the anode with the +5V rail of the optocoupler (Pin IC2:8 )If this doesn't help you to detect the error, continue with the next step:In this configuration the LED should only lit when MIDI data is received. Than more MIDI events are received a time, than brigther the LED. If the LED doesn't lit, check the polarity of the protection diode before the optocoupler. Also check the polarity of the MIDI cable.If both tests didn't help, ensure that your MIDI interface is working correctly: take a MIDI cable and connect the MIDI Out with the MIDI In of your interface in order to get a feedback loop. Send a MIDI event with MIDI-Ox (just use the virtual keyboard..) and check if the data at the input and output monitor is the same.disconnect the LED after the tests, otherwise the PIC will receive no MIDI data.Best Regards, Thorsten.FAQMARKER Quote Link to comment Share on other sites More sharing options...
jeroddumas Posted June 17, 2003 Author Report Share Posted June 17, 2003 ;Well it seems as though my problem was in the LTC. I only had one IC stuffed although it seems as though this shouldn't have made a difference. Got the core up and running, now i got to get the LCD working. ;D ;D Quote Link to comment Share on other sites More sharing options...
goule Posted September 19, 2005 Report Share Posted September 19, 2005 Both tests are ok for me but I still don't seem to receive midi. My midibox was working until yesterday : (I had then the bad idea to reupload the MIOS), so it has already worked (and no hardware changes since, only programs updates) ... Midi In doesn't seem to work, everything is well configured in MidiOx, I don't what to do now ... :'(The only tests that does not seem to pass is this one : http://www.ucapps.de/howtodebug/mbhp_core_extract_opto_test.gifCould it be possible that my octocoupler passed away ?Goule Quote Link to comment Share on other sites More sharing options...
raphael Posted September 20, 2005 Report Share Posted September 20, 2005 The only tests that does not seem to pass is this one : http://www.ucapps.de/howtodebug/mbhp_core_extract_opto_test.gifCould it be possible that my octocoupler passed away ?Yes, this points to a bad optocoupler. But first check if the voltage at the of the Coupler-pins (+5V at Pin 8 ). Quote Link to comment Share on other sites More sharing options...
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