monokinetic Posted November 16, 2010 Report Share Posted November 16, 2010 Hi all, While preparing to finish my upgrade to MBSEQv4 I have found a strange problem on my Core32 board. Currently I have my SDCard working, LCDs working, external power ready. But when I hooked up my DIN/DOUT boards they seem to not be working correctly. I got the same behaviour with or without a customised HWConfig file on my SDCard. After lots of following cables and making sure I have the SC/RC/SI/SO lines connected correctly, I tried checking the Core32 J8/J9 connector to make sure R31 (the 4x220 Ohm SIL resistor) is working correctly. I found that something was very odd, I could measure 30k resistance between VS and SC/RC/SI/SO! I removed the SIL resistor and found I have no resistance on the SC/RC/SI/SO lines. I tested the SIL resistor now that I have removed it and it seems fine i.e. 220 Ohms from the dotted pin to each other pin. Before I install a new 220 Ohm SIL resistor, I would like to ask if it would be worth trying the connection to my DIN/DOUT boards without the 220 Ohm SIL resistor installed? Or should I just install the new one and see what happens with that one? Thanks in advance for any help. David Quote Link to comment Share on other sites More sharing options...
Hawkeye Posted November 16, 2010 Report Share Posted November 16, 2010 did´cha install the arnold? Quote Link to comment Share on other sites More sharing options...
monokinetic Posted November 16, 2010 Author Report Share Posted November 16, 2010 did´cha install the arnold? Err I'm not sure if I understand? Arnold? Quote Link to comment Share on other sites More sharing options...
Hawkeye Posted November 16, 2010 Report Share Posted November 16, 2010 terminator :) Quote Link to comment Share on other sites More sharing options...
TK. Posted November 16, 2010 Report Share Posted November 16, 2010 Hi, the DIN/DOUT modules cannot be controlled without pull-up resistors, because pins are working in Open Drain mode, which means that they are switching between Vss (for logic-0) and high-impedance (for logic-1) I could measure 30k resistance between VS and SC/RC/SI/SO Nothing to be worried about, you measured the resistance between VS -> any other component (e.g. chips) -> VD -> pull-up resistor The path between Vd->SC/RC/SI/SO is the interesting one. It would be interesting what you mean exactly with "they don't work correctly" - what is the effect? Are they not working at all (no LEDs enabled, no button event regognized), or do they behave randomly? Are LEDs even flickering, and/or do buttons trigger the wrong functions? Best Regards, Thorsten. Quote Link to comment Share on other sites More sharing options...
monokinetic Posted November 17, 2010 Author Report Share Posted November 17, 2010 terminator :) Aha :) but terminate what? The DIN/DOUT chain? If so then can you point me towards where this is described, I don't see it anywhere on ucapps.de.... is this a new thing? My DIN/DOUT chain has been working as is for over 3 years now. Quote Link to comment Share on other sites More sharing options...
Hawkeye Posted November 17, 2010 Report Share Posted November 17, 2010 the missing termination is probably not the reason for your trouble, but it is documented here: http://ucapps.de/midibox_seq/mbseq_v4_din.pdf Quote Link to comment Share on other sites More sharing options...
monokinetic Posted November 17, 2010 Author Report Share Posted November 17, 2010 (edited) Hi Thorsten, thanks for the info. the DIN/DOUT modules cannot be controlled without pull-up resistors, because pins are working in Open Drain mode, which means that they are switching between Vss (for logic-0) and high-impedance (for logic-1) Ok, I had a feeling this was probably not too helpful. I'm a bit stuck and I was trying to come up with other things to test :) Nothing to be worried about, you measured the resistance between VS -> any other component (e.g. chips) -> VD -> pull-up resistor Aha, from memory I think there was also resistance between some of the SI/RC pins, but I forget exactly which. The path between Vd->SC/RC/SI/SO is the interesting one. So I will install R31 again and test exactly where I was measuring the resistance tonight. It would be interesting what you mean exactly with "they don't work correctly" - what is the effect? Are they not working at all (no LEDs enabled, no button event regognized), or do they behave randomly? Are LEDs even flickering, and/or do buttons trigger the wrong functions? Well, to be more specific each time I turn on, a random set of LEDs is lit. No buttons on my front panel or encoder seem to make any difference i.e. I cant change any parameters on the LCD and the GP buttons do not toggle LEDs on or off. I guess my next step is to put R31 back and post here exactly which pins have the resistance. Any other suggestions? Edit: update is that with R31 back in, on the Core32 board J8/J9 (with nothing else plugged in) I can measure 220 Ohm from VD to SC, RC and SO. But nothing on SI. I checked and the IDC socket SI pin is definitely soldered correctly, so I guess it must be something between the SI pin and the R31. Any ideas what could cause it? Cheers David Edited November 17, 2010 by monokinetic Quote Link to comment Share on other sites More sharing options...
monokinetic Posted November 17, 2010 Author Report Share Posted November 17, 2010 the missing termination is probably not the reason for your trouble, but it is documented here: http://ucapps.de/midibox_seq/mbseq_v4_din.pdf Ok, now I know what you mean :D I must admit I don't have the termination on either chain, I know it was recommended at one point with MBSeq3, but I had already put mine in the box by the time I realised! I will give it a try tomorrow though, thanks for the pointer. Hasta la vista! David Quote Link to comment Share on other sites More sharing options...
monokinetic Posted November 19, 2010 Author Report Share Posted November 19, 2010 (edited) Hurrah, I have got the DIN and DOUTs working perfectly now. Silly me, I had mixed the SC and RC lines :blush: I will reply to myself just to finish this off. Edit: update is that with R31 back in, on the Core32 board J8/J9 (with nothing else plugged in) I can measure 220 Ohm from VD to SC, RC and SO. But nothing on SI. I checked and the IDC socket SI pin is definitely soldered correctly, so I guess it must be something between the SI pin and the R31. Any ideas what could cause it? There should not be any resistance on SI, I should have double checked the schematic before posting. Still making noobie mistakes after 8 years here, ah well :hmm: Case closed! Cheers David Edited November 19, 2010 by monokinetic Quote Link to comment Share on other sites More sharing options...
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