Guest Vol Posted December 18, 2002 Report Share Posted December 18, 2002 HelloI just finished making the midibox16 and it works better than I had hoped so thanks.I have a small problem though ....... Midi out works fine ...... midi in however does not, it seems if a message is sent to the midibox it freezes up and displays the midi time out message. I tried to set it up to control my alpha juno synth (which uses sysex) and it displays the event coming in but then freezes up and it shows the time out message .......... same thing when I had it hooked up and I was using logic.Any Ideas?ThanksJustin ??? Quote Link to comment Share on other sites More sharing options...
Guest Vol Posted December 18, 2002 Report Share Posted December 18, 2002 HelloI just finished making the midibox16 and it works better than I had hoped so thanks.I have a small problem though ....... Midi out works fine ...... midi in however does not, it seems if a message is sent to the midibox it freezes up and displays the midi time out message. I tried to set it up to control my alpha juno synth (which uses sysex) and it displays the event coming in but then freezes up and it shows the time out message .......... same thing when I had it hooked up and I was using logic.Any Ideas?ThanksJustin ??? Quote Link to comment Share on other sites More sharing options...
TK. Posted December 19, 2002 Report Share Posted December 19, 2002 Hi Justin,did you follow the instructions under http://www.ucapps.de/howtodebug.html ?Best Regards, Thorsten. Quote Link to comment Share on other sites More sharing options...
TK. Posted December 19, 2002 Report Share Posted December 19, 2002 Hi Justin,did you follow the instructions under http://www.ucapps.de/howtodebug.html ?Best Regards, Thorsten. Quote Link to comment Share on other sites More sharing options...
Guest Vol Posted December 19, 2002 Report Share Posted December 19, 2002 hello, yes I have done the debug thing or tried to .....I know midi out works but after burning the test code I didn't get any midi out showing in midi-OX, couldn't get the in port test to work either. Maybe I burnt the code wrong but it verified ok so .................. So I put 1909 firmware in and tried again, still the same. With midi-OX running I plugged my synth into the midi-box and midi-ox shows messages from the out porrt, so it is working but it seems a bit unstable or something. the messages are a bit jumpy. I'm gonna go and hook up the synth straight into the pc to see what the difference is .............ThanksJustinoh and I tried changing the pull up resistor value and shorting the 220 ohm resistor on the in port but no luck ..... I'm using martins PCB with only the in/out midi connectors wired up ..... Quote Link to comment Share on other sites More sharing options...
Guest Vol Posted December 19, 2002 Report Share Posted December 19, 2002 hello, yes I have done the debug thing or tried to .....I know midi out works but after burning the test code I didn't get any midi out showing in midi-OX, couldn't get the in port test to work either. Maybe I burnt the code wrong but it verified ok so .................. So I put 1909 firmware in and tried again, still the same. With midi-OX running I plugged my synth into the midi-box and midi-ox shows messages from the out porrt, so it is working but it seems a bit unstable or something. the messages are a bit jumpy. I'm gonna go and hook up the synth straight into the pc to see what the difference is .............ThanksJustinoh and I tried changing the pull up resistor value and shorting the 220 ohm resistor on the in port but no luck ..... I'm using martins PCB with only the in/out midi connectors wired up ..... Quote Link to comment Share on other sites More sharing options...
Guest Vol Posted December 19, 2002 Report Share Posted December 19, 2002 Yup, the signal is completely different when I go straight into the PC, so something ain't right ... Quote Link to comment Share on other sites More sharing options...
Guest Vol Posted December 19, 2002 Report Share Posted December 19, 2002 Yup, the signal is completely different when I go straight into the PC, so something ain't right ... Quote Link to comment Share on other sites More sharing options...
TK. Posted December 20, 2002 Report Share Posted December 20, 2002 Do you notice a flickering of the pot values, or do you see unwanted MIDI events (i.E pitch bender, Aftertouch) although these events haven't been assigned to the pots/buttons. In both cases this could be related to the power supply. The core voltage should be about 5V, lower voltages can cause problems with the MIDI transfer (...and much higher voltages kill the chip!)Best Regards, Thorsten. Quote Link to comment Share on other sites More sharing options...
TK. Posted December 20, 2002 Report Share Posted December 20, 2002 Do you notice a flickering of the pot values, or do you see unwanted MIDI events (i.E pitch bender, Aftertouch) although these events haven't been assigned to the pots/buttons. In both cases this could be related to the power supply. The core voltage should be about 5V, lower voltages can cause problems with the MIDI transfer (...and much higher voltages kill the chip!)Best Regards, Thorsten. Quote Link to comment Share on other sites More sharing options...
Guest Vol Posted December 21, 2002 Report Share Posted December 21, 2002 I don't see flickering or unwanted midi messages but just every midi signal I send into it gives me the 'Midi time out, whats up?' message.I did use a slightly higher value transformer than recommended, it is about 12v instead of 7-9, there is a stable 4.94v from the transistor. I might try a lower value transfomer or an external one, as it is on the PCB.Hmmmm ....... I just tested the voltage on the output of the transformer and it is about 11v when the backlight of the LCD is off, but drops to about 7.4 when I turn the B/L up full ...... is this normal?ThanksJustin Quote Link to comment Share on other sites More sharing options...
Guest Vol Posted December 21, 2002 Report Share Posted December 21, 2002 I don't see flickering or unwanted midi messages but just every midi signal I send into it gives me the 'Midi time out, whats up?' message.I did use a slightly higher value transformer than recommended, it is about 12v instead of 7-9, there is a stable 4.94v from the transistor. I might try a lower value transfomer or an external one, as it is on the PCB.Hmmmm ....... I just tested the voltage on the output of the transformer and it is about 11v when the backlight of the LCD is off, but drops to about 7.4 when I turn the B/L up full ...... is this normal?ThanksJustin Quote Link to comment Share on other sites More sharing options...
TK. Posted December 23, 2002 Report Share Posted December 23, 2002 Hi Justin,yes, your transformer works correctly. The voltage falls due to the internal resistance of the transformer - see also: http://www.nzart.org.nz/nzart/examinat/amateur%20radio%20study%20guide/Course%20Files/Power%20Supplies/STUDY%20NOTES%20-%20POWER%20SUPPLIES.htmThe internal resistance is the reason why we are using a 7805 to regulate the supply voltage Vdd for the PIC.To your problem: if every tweak fails the only way to get it running is the use of another optocoupler. If I only had known that the CNY17 causes so much trouble, I had replaced it by a better optocoupler years before the first PCB layouts were released :-/You could try the 6N138 circuit from the MBHP - if this works better with your synth, it's time for me to add a big warning to the MIDIbox Plus pageBest Regards, Thorsten. Quote Link to comment Share on other sites More sharing options...
TK. Posted December 23, 2002 Report Share Posted December 23, 2002 Hi Justin,yes, your transformer works correctly. The voltage falls due to the internal resistance of the transformer - see also: http://www.nzart.org.nz/nzart/examinat/amateur%20radio%20study%20guide/Course%20Files/Power%20Supplies/STUDY%20NOTES%20-%20POWER%20SUPPLIES.htmThe internal resistance is the reason why we are using a 7805 to regulate the supply voltage Vdd for the PIC.To your problem: if every tweak fails the only way to get it running is the use of another optocoupler. If I only had known that the CNY17 causes so much trouble, I had replaced it by a better optocoupler years before the first PCB layouts were released :-/You could try the 6N138 circuit from the MBHP - if this works better with your synth, it's time for me to add a big warning to the MIDIbox Plus pageBest Regards, Thorsten. Quote Link to comment Share on other sites More sharing options...
Guest Vol Posted December 29, 2002 Report Share Posted December 29, 2002 Ok, so I put in the 6N138 and it works now, doesn't give me the midi time out message ........... but when I go to learn a message from my synth, (alpha Juno 1) say the VCF Freq, nothing comes up, but when I play a note on the keyboard it recgnises it. Now I know the Juno uses sysex for it's parameters, I thought the midibox could do this ...............ThanksJustin Quote Link to comment Share on other sites More sharing options...
Guest Vol Posted December 29, 2002 Report Share Posted December 29, 2002 Ok, so I put in the 6N138 and it works now, doesn't give me the midi time out message ........... but when I go to learn a message from my synth, (alpha Juno 1) say the VCF Freq, nothing comes up, but when I play a note on the keyboard it recgnises it. Now I know the Juno uses sysex for it's parameters, I thought the midibox could do this ...............ThanksJustin Quote Link to comment Share on other sites More sharing options...
TK. Posted January 1, 2003 Report Share Posted January 1, 2003 Hi Justin,thanks for the input! I've decided to exchange the CNY17 by a 6N138 in all schematics and PCBs of MIDIbox Plus so that nobody runs into this problem anymore.Juno SysEx: since the structure of SysEx strings can be very different, it's not possible to learn them. But they can be realized with Meta Events. Can you send me a MIDI specification sheet of this synth?Best Regards, Thorsten. Quote Link to comment Share on other sites More sharing options...
TK. Posted January 1, 2003 Report Share Posted January 1, 2003 Hi Justin,thanks for the input! I've decided to exchange the CNY17 by a 6N138 in all schematics and PCBs of MIDIbox Plus so that nobody runs into this problem anymore.Juno SysEx: since the structure of SysEx strings can be very different, it's not possible to learn them. But they can be realized with Meta Events. Can you send me a MIDI specification sheet of this synth?Best Regards, Thorsten. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.