macroman Posted October 28, 2007 Report Share Posted October 28, 2007 Hi,just registered on the forum and wanted to bring out the problem I'm suffering with. First of all I'm a sort of newbie with electronics and doing the learning by the hardest way (try/mistake/learn) :-)I've just soldered up the core module, but I'm not getting anything from the MIDI (MIOS studio, midi in monitor).I'm using C64 -power supply. 9VAC is connected on the board. Voltages on the measuring points seems to be okay (~5,06VDC). I did the midi LED-test, but no activity going on.I've doublechecked the solderings. Could this indicate to dead IC1/IC2?I'm not sure what more information is needed to bring out for a possible help, but these are for starters. Quote Link to comment Share on other sites More sharing options...
nILS Posted October 28, 2007 Report Share Posted October 28, 2007 Hiya and welcome aboard!Voltages of 5.06V are fine.Check the following:- Solderings REALLY okay? No bridges?- Voltages everywhere? Not just on some part of the board?- MIOS (or at least the Bootstrap loader) on the PIC?If the answer to all these is "yes" your optocoupler may actually be dead. I take it these are fairly easy to kill. Quote Link to comment Share on other sites More sharing options...
macroman Posted October 29, 2007 Author Report Share Posted October 29, 2007 Hiya and welcome aboard!Voltages of 5.06V are fine.Check the following:- Solderings REALLY okay? No bridges?- Voltages everywhere? Not just on some part of the board?- MIOS (or at least the Bootstrap loader) on the PIC?If the answer to all these is "yes" your optocoupler may actually be dead. I take it these are fairly easy to kill.Hi and thanks! I'll go through all the solderings once more. I'll also check the voltages on other parts of the board, but that needs more investigating to know what the values should be on a certain points.MIOS and Bootstrap loader should be already on the PIC, since its PIC18F452.Do you know if there's some measuring tests to make sure if optocoupler is dead? Quote Link to comment Share on other sites More sharing options...
nILS Posted October 29, 2007 Report Share Posted October 29, 2007 If you measured all the voltages as described on ucapps you should be fine. Just check some other pins to see that there's NO voltage there =)I assume you got the PIC pre-programmed?I have a simple optocoupler-test board here, which I made according to some schematic about 3 years ago, so there IS some info on it somewhere around here - I just don't know where anymore. A little searching should give you the results you need though.EDIT: Found it: http://www.ucapps.de/howto_debug_midi.html. There is a simple schematic to test the opto and an in-circuit one as well. Quote Link to comment Share on other sites More sharing options...
macroman Posted October 29, 2007 Author Report Share Posted October 29, 2007 To be more specific what the problem is: the core module isn't sending any midi information to computer. Module is Core R4D.Yes, PIC is pre-programmed with BSL 1.2B and MIOS V1.9F (with ID headers 0000 0000 0000 0000), as it's also labeled on the PIC.In ucapps troubleshoot instructions (http://www.ucapps.de/howtodebug/mbhp_core_extract_measuring_vdd.gif) is said that TX and RX lines are steady 5V when nothing is sent. I connected a LED to IC1/12(vss) and IC1/25(tx), and it gave steady 5V and no blinks on light. Shouldn't the MIOS send a signal once after power on?According to schematics (http://www.ucapps.de/mbhp/mbhp_core_v3.pdf), is TX even going through the optocoupler? As far as I see it, it doesn't? So perhaps the problem is with the PIC. Quote Link to comment Share on other sites More sharing options...
nILS Posted October 29, 2007 Report Share Posted October 29, 2007 Within 2 seconds after power up MIOS should send an upload request.You don't happen do have an LCD handy, do you? Quote Link to comment Share on other sites More sharing options...
macroman Posted October 30, 2007 Author Report Share Posted October 30, 2007 Within 2 seconds after power up MIOS should send an upload request.You don't happen do have an LCD handy, do you?Maybe I should build up the minimal control unit (http://www.ucapps.de/midibox_sid_cs/mini_unit.jpg) to make the problem solving easier, and since I'm going to add the control unit after all.edit: a little research exposed that I should only get an LCD panel. No need for the whole control surface at this point (?) Quote Link to comment Share on other sites More sharing options...
TK. Posted October 30, 2007 Report Share Posted October 30, 2007 Since MIOS has been pre-installed, the bootloader will only send a single upload request message during power-on before MIOS is started. This one is hard to notify. No, the Tx signal doesn't go through the optocoupler - with the Core MIDI Out -> PC MIDI In connection it will be connected to the optocoupler of your PC MIDI Interface.If the Tx line outputs 5V, it's very likely that the PIC is running, otherwise Tx would be around 0VSo, it looks like an issue with the MIDI In Port, with the MIDI connections to your PC, or with the driver of your MIDI interface.Yes, it is sufficient to connect only the LCD for this check, buttons and encoders can be connected later. Note that for MBSID V2 a SHIFT/UP/DOWN button should be added as well (see MBSID V2 Manual, Hardware chapter).Best Regards, Thorsten. Quote Link to comment Share on other sites More sharing options...
nILS Posted October 30, 2007 Report Share Posted October 30, 2007 Once again, TK steps in, corrects my mistakes and saves the day :D Quote Link to comment Share on other sites More sharing options...
macroman Posted October 30, 2007 Author Report Share Posted October 30, 2007 Thanks guys for your help. Now I've connected 2x16 lcd screen to core board, and everything seems to be okay as it states "READY". I also uploaded the SID-software and it went fine. Now there's mbsid running.What's funny; I still don't get any messages to PC Midi in monitor when I power up the core module. So whether I've succeed to upload the mbsid, it could still be that the core's midi out isn't working. Right? Well however, I still keep on going and the next step is to connect SID module to core module. We'll see the midi out functioning later... Quote Link to comment Share on other sites More sharing options...
stryd_one Posted October 31, 2007 Report Share Posted October 31, 2007 Well you certainly didn't upload it with MIOS studio in smart mode! hHeheheYour upload may or may not have been completely successful... Although it seems fine from what you said :)it could still be that the core's midi out isn't working. Right? Possibly, but probably not. The same situation as above still applies. Quote Link to comment Share on other sites More sharing options...
macroman Posted October 31, 2007 Author Report Share Posted October 31, 2007 Thanks for the previous help, really appreciate it!...but damn, now I'm suffering problems with SID module's power. I've powered SID module like this http://www.ucapps.de/mbhp/mbhp_sid_c64_psu.pdf. First I measured 4,10V behind rectifier, then after "fooling around" I actually got 15V. Then few minutes later it was 4,10V again. Could it be faulty rectifier or bad soldering somewhere? If it's soldering or other component, which components should I check first since I've already tried to find the reason? :-) Quote Link to comment Share on other sites More sharing options...
stryd_one Posted November 1, 2007 Report Share Posted November 1, 2007 The power problems could be the crux of it all... what was the "fooling around"? Could be lots of things, the more data we have on the problem, the better guess we can take. Quote Link to comment Share on other sites More sharing options...
macroman Posted November 1, 2007 Author Report Share Posted November 1, 2007 The power problems could be the crux of it all... what was the "fooling around"? Could be lots of things, the more data we have on the problem, the better guess we can take.That's something I can't accurately tell; I found a bad soldering on rectifier and fixed that up, changed the power cables to core module and measured how the values should be behind it, changed the power cables back to sid module and got 15V, then I removed the power and for some reason put it back after few minutes and it wasn't 15V anymore.I think that's not helpful, but I thought could that voltage behaviour tell something about some specific component's fault. :-)edit: other funny thing is, that I've soldered up the following psu board exact way, but I'm not getting 14V out of schematics' 14V line :-S It gives something around 5.10V and 5,20V http://www.danielprice.org.uk/synth-diy/images/sid_psu_layout.jpg. This makes me doubt my logical thinking, but I'll not give up and will do some research later.. Quote Link to comment Share on other sites More sharing options...
TK. Posted November 1, 2007 Report Share Posted November 1, 2007 Could it be, that the socket for the C64 PSU plug is broken? I would expect such an effect if one of the 9v AC pins has no connection.Best Regards, Thorsten. Quote Link to comment Share on other sites More sharing options...
macroman Posted November 1, 2007 Author Report Share Posted November 1, 2007 Could it be, that the socket for the C64 PSU plug is broken? I would expect such an effect if one of the 9v AC pins has no connection.I doubt, because I've measured the AC voltages from the cable's plug = 9VAC, and after it's been plugged in to the original C64 female connector = 9VAC. So I'm sure i'm doing something wrong after that, but don't know what exactly, yet.EDIT: Actually you were basically right! 9VAC pins were okay, but the switch I added didn't connect line when it was switched on, so the circuit didn't receive the other part of 9VAC. I removed the switch and now I get 14VAC!! Great success, now I can power up both SID and Core. Thanks TK! 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.