Guest Kayzer Posted July 5, 2004 Report Share Posted July 5, 2004 Hello,How can I check if the serial register is broke? Without the chips I'm getting steady 4,9v to the buttons. With the register it's only 2,8v and obviously not working... Quote Link to comment Share on other sites More sharing options...
Milkmansound Posted July 5, 2004 Report Share Posted July 5, 2004 maybe try and switch the chips around (ie, shotgun the parts) and see if you have the same voltage drop - most likely something beyond the chip is causing the problem. Which pins are low? Quote Link to comment Share on other sites More sharing options...
Guest Kayzer Posted July 25, 2004 Report Share Posted July 25, 2004 maybe try and switch the chips around OK, now I measure 5v on every pin and 0v when button is pressed. Still the display only shows "Waiting for DIN or AIN event". Is is possible the the 74HC165 are broke because they were inverse inserted in the ic socket?UPDATE:All buttons are getting steady 5v now. Buttons 0 -> 15 are working perfectly. But from the third 74HC165 onwards thing go wrong. The voltage is correct but pressing a button doesn't reflect in the lcd. Only button 19 displays random button numbers (between 15 and 128 ). Quote Link to comment Share on other sites More sharing options...
doc Posted July 26, 2004 Report Share Posted July 26, 2004 Sounds like a broken chip...The problem with the DIN is that it is a CHAIN.So if one chip is faulty the other Dins didn't respond anymore.Try to change the chip for the buttons 9-16 and the chip after (17-24).greets doc Quote Link to comment Share on other sites More sharing options...
Guest Kayzer Posted July 26, 2004 Report Share Posted July 26, 2004 Try to change the chip for the buttons 9-16 and the chip after (17-24).I only have 20 buttons so I don't use the last (fourth) ic. I just changed the first (button 1-8 ) ic with the third (button 16-24, the problematic one) and than the din isn't working anymore so I think that the ic is broken. I'm gonna order right away some new ones and let now if that fixed the problem. Quote Link to comment Share on other sites More sharing options...
Guest Kayzer Posted July 28, 2004 Report Share Posted July 28, 2004 I changed all the four IC with fresh ones and the problem stills persists :(What works:first ic -> left,right,exec,snapshot & F1 to F4second ic -> buttons 1 to 8third ic -> buttons 9 to 13 do nothing & buttons 13 to 16: button 16 triggers all buttons ??? (full asterisk row on lcd with midibox v2.3)fourth ic -> does nothing PLease help! Quote Link to comment Share on other sites More sharing options...
jeroddumas Posted July 29, 2004 Report Share Posted July 29, 2004 which mios program are you using. I am having some similar problems also. Quote Link to comment Share on other sites More sharing options...
Guest Kayzer Posted July 29, 2004 Report Share Posted July 29, 2004 which mios program are you using.I'm using MIOS v1.7 and the MIDIO128 program so I can only test the DIN.Just tried with MIOS v1.6 and v1.1. The problem still persists :( Quote Link to comment Share on other sites More sharing options...
jeroddumas Posted July 29, 2004 Report Share Posted July 29, 2004 did you use the premade pcb. or veroboard. My din is on veroboard, but I have traced everything with no good results. I really have no idea of whats going on but it looks like it is easy to destroy the shift registers. ti.com for samples, so it will not cost you any money. Quote Link to comment Share on other sites More sharing options...
Guest Kayzer Posted July 29, 2004 Report Share Posted July 29, 2004 I use the premade pcb from Mike. Quote Link to comment Share on other sites More sharing options...
jeroddumas Posted July 29, 2004 Report Share Posted July 29, 2004 i am willing to bet you have a bad chip Quote Link to comment Share on other sites More sharing options...
Guest didifeed Posted July 29, 2004 Report Share Posted July 29, 2004 yessss....i would also guess that the register is faulty. look at fairchildsemi.com or ti.com if you need replacements ;) these companies are really fast in sending samples Quote Link to comment Share on other sites More sharing options...
Guest Kayzer Posted July 29, 2004 Report Share Posted July 29, 2004 i am willing to bet you have a bad chipWell, like I said before I replaced all four IC's with brand new ones (from Philips) and still there is a problem from the third ic onwards. I think it must be some kind of wiring error but I rechecked the pcb and measured no shorts anywere. I'm desperate...I repeat:All buttons are getting steady 5v now. Buttons 0 -> 15 are working perfectly. But from the third 74HC165 onwards thing go wrong. The voltage is correct but pressing a button doesn't reflect in the lcd. Only button 19 displays random button numbers (between 15 and 128 ). Quote Link to comment Share on other sites More sharing options...
moebius Posted July 30, 2004 Report Share Posted July 30, 2004 "It's only important that the last input shift register is terminated with ground level (0V), so that the firmware doesn't recognize invalid values." ??? Quote Link to comment Share on other sites More sharing options...
Guest Kayzer Posted July 30, 2004 Report Share Posted July 30, 2004 "It's only important that the last input shift register is terminated with ground level (0V), so that the firmware doesn't recognize invalid values." Â ???Which pins from the IC have to be grounded? Where did you find this advice? It's not on the DIN module page. Quote Link to comment Share on other sites More sharing options...
moebius Posted July 30, 2004 Report Share Posted July 30, 2004 Kayzer,I was just wondering, it's straight out of a MIDIO128 page under The Hardware topic. And seems like false advice. As (normally) when button is pressed, contact is closed and input is pulled low. So I think that serial register chain should already be terminated by last pullup resistor (R33-R36) connected to serial input of the last chip installed (pin10). (I think that grounding it makes PIC think that all further buttons are pressed)Only button 19 displays random button numbers (between 15 and 128 ).Hmm.. like it's being only button read.. directly by serial input grr ;) Check the connections around third chip.. try to swap 3rd chip to old (not the broken) one.Bye, Moebius Quote Link to comment Share on other sites More sharing options...
Guest Kayzer Posted August 3, 2004 Report Share Posted August 3, 2004 Hooray!Everything is working now. The bridges for clock input at ic3 and 4 weren't rightly soldered. So, I guess for everyone with DIN problems; "Check ya board!" Multimeter is handy!Greetz,Kayzer Quote Link to comment Share on other sites More sharing options...
jeroddumas Posted August 3, 2004 Report Share Posted August 3, 2004 should the clock input measure a voltage, if so what voltage are you getting. I am having similar problems with my din. But what is happening is when the 7th and 8th shift registers are plugged in all other button on the din stop working. If i unsolder the clock line to these the other buttons work fine. I have checked and checked my soldering. maybe there is something I am missing??? Quote Link to comment Share on other sites More sharing options...
moebius Posted August 3, 2004 Report Share Posted August 3, 2004 Hi,should the clock input measure a voltage, if so what voltage are you getting.It's a fast periodic DC pulse. Your multimeter doesn't have fast enough sample rate to capture that, but it might still show something, like variable results.Digital signals, datalines ect. are easily checked for apparent faults with a simple (and cheap) logic probe. It should be able to distinguish between logic 1 / 0 and pulse trains..If i unsolder the clock line to these the other buttons work fine.Hmm.. It seems that those shift registers corrupt the clock line. Unplug those, and check for shorts.Bye, Moebius Quote Link to comment Share on other sites More sharing options...
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