jonkull Posted July 8, 2007 Report Share Posted July 8, 2007 I finished building my MBSid this morning. It worked great for about 3-4 hours then the LCD suddenly filled with random characters. It responds to midi and produces audio and the buttons and knob appear to be working. I used MIOS Studio to reupload the mios and app and received no errors. My display cable seems fine. I read another post here where someone had a similar problem and fixed it by reburning the PIC. I will not be able to do this for a few days. Is there anything else I should look at in the meantime? Quote Link to comment Share on other sites More sharing options...
seppoman Posted July 8, 2007 Report Share Posted July 8, 2007 As it did already work, it is probably no software problem - I would check and in doubt resolder every wire of the display connection, check for shorts between the connector pins on the core (sometimes tiny blobs of tin fly around on a board after soldering, perhaps one has found a place between the pins). I´d say it´s 99% a hardware problem, so check everything and whe you´re finished, check again :)Good luck,Seppoman Quote Link to comment Share on other sites More sharing options...
jonkull Posted July 8, 2007 Author Report Share Posted July 8, 2007 I'm wondering...can temperature cause something like this? Last night it was 85F in my apartment. This morning it's in the low 60s and the MBSid is working perfectly fine with no LCD strangeness. I had some issues with my Kurzweil randomly dumping it's presets last summer and was told that it was due to temperature (max temp for a kurzweil is 104F so if it's in a rack with poor ventilation and a bunch of gear all giving off heat...). Last night right after I made this post my K2600 dumped it's presets again. I noticed that my MBSid was pretty hot when I shut it off. Just a thought. Quote Link to comment Share on other sites More sharing options...
TK. Posted July 8, 2007 Report Share Posted July 8, 2007 Hi,yes, higher temperatures can cause such effects. Do you have a datasheet of your LCD? What is the specified temperature range? Is your MIDIbox built into a closed plastic case without "ventilation slots"? Maybe it makes also sense to measure the voltage at J2 when this happens. If it is much below 5V (I mean, 4.8V or less) due to increased heat, such random effects could happen as well. In this case, a heatsink for the 7805 could help - or if your MIDIbox is built into a metal case: just screw the 7805 on the bottom or sidepanel of your case.Best Regards, Thorsten. Quote Link to comment Share on other sites More sharing options...
jonkull Posted July 9, 2007 Author Report Share Posted July 9, 2007 Hi,yes, higher temperatures can cause such effects. Do you have a datasheet of your LCD? What is the specified temperature range? Is your MIDIbox built into a closed plastic case without "ventilation slots"? Maybe it makes also sense to measure the voltage at J2 when this happens. If it is much below 5V (I mean, 4.8V or less) due to increased heat, such random effects could happen as well. In this case, a heatsink for the 7805 could help - or if your MIDIbox is built into a metal case: just screw the 7805 on the bottom or sidepanel of your case.Best Regards, Thorsten.Thanks for the response. According to the datasheet the maximum operating temp for the LCD is 50C (122F). My midibox is in an aluminum case with ventilation slots running across it's entire width of the back panel. The 7805 does have a heatsink on it. Maybe it's not pulling enough heat. I'll try connecting it to the case and see if that helps. Quote Link to comment Share on other sites More sharing options...
TK. Posted July 9, 2007 Report Share Posted July 9, 2007 I'm surprised that you already took care for a heatsink and ventilation slots - your MIDIbox seems to be constructed better than many other ones. Also the operating temperature range of the LCD seems to be normal.If random characters appear again, please measure the supply voltage. This could give a hint (but propably it doesn't... just a hope ;-))Best Regards, Thorsten. Quote Link to comment Share on other sites More sharing options...
jonkull Posted July 11, 2007 Author Report Share Posted July 11, 2007 I no longer think it's heat as my LCD is now permanently filled with random characters. The unit is still functional..responds to midi and produces audio the LCD just doesn't work. I guess it's time to check the wiring...yet again. :( Quote Link to comment Share on other sites More sharing options...
TK. Posted July 11, 2007 Report Share Posted July 11, 2007 Maybe it's possible to narrow down the issue: which kind of characters do you see on screen? Are they changing from time to time, or are these always the same characters?Do you see some text (e.g. Chn.) which doesn't change?Best Regards, Thorsten. Quote Link to comment Share on other sites More sharing options...
jonkull Posted July 12, 2007 Author Report Share Posted July 12, 2007 Maybe it's possible to narrow down the issue: which kind of characters do you see on screen? Are they changing from time to time, or are these always the same characters?Do you see some text (e.g. Chn.) which doesn't change?Best Regards, Thorsten.As it boots it shows $$$ on top right and $f7477. on bottom right. After it's done booting it shows $$lgteT$lenf54 on top line and $f7477.5V$DMWlovet on bottom line. It's always the same. As I cycle through the patches the characters change as I turn the knob. None of the text is anything readable as far as names or actual words. For instance patch #1 shows ---5 on the top line with nothing on the bottom line. There's no consistancy between patches...they all appear different but each patch remains constant. For example when I scroll back to patch 1 from patch 2 it goes back to ---5. Quote Link to comment Share on other sites More sharing options...
TK. Posted July 12, 2007 Report Share Posted July 12, 2007 It's maybe a short, by sending different characters the affected data line can be found out.MIOS Studio provides a special debug window which allows you to send characters to the LCD. They will be visible for 2 seconds, before the MBSID application switches to the previous screen again.Could you please write down which characters you see when following strings are sent to MBSID: (these are 8 spaces)0000000011111111222222224444444488888888@@@@@@@@PPPPPPPPaaaaaaaappppppppAre you using a PIC18F452, or already a PIC18F4685?Best Regards, Thorsten. Quote Link to comment Share on other sites More sharing options...
jonkull Posted July 12, 2007 Author Report Share Posted July 12, 2007 It's maybe a short, by sending different characters the affected data line can be found out.MIOS Studio provides a special debug window which allows you to send characters to the LCD. They will be visible for 2 seconds, before the MBSID application switches to the previous screen again.Could you please write down which characters you see when following strings are sent to MBSID: (these are 8 spaces)0000000011111111222222224444444488888888@@@@@@@@PPPPPPPPaaaaaaaappppppppAre you using a PIC18F452, or already a PIC18F4685?Best Regards, Thorsten.When I powered my MBSid up this morning the LCD was working fine again. I turned it off and back on and it's back to random garbage.Neither...I'm using a 18F4620.As for the strings of characters...when I send them from MIOS studio all I get is random garbage. Nothing repeats. For example sending 00000000 gets a completely different result every time it's sent. However the characters I described in my previous post are constant. Quote Link to comment Share on other sites More sharing options...
TK. Posted July 12, 2007 Report Share Posted July 12, 2007 PIC18F4620... hm, I haven't tried the MBSID application on this derivative for a long time - which MIOS release are you using, and which firmware version?Best Regards, Thorsten. Quote Link to comment Share on other sites More sharing options...
jonkull Posted July 12, 2007 Author Report Share Posted July 12, 2007 PIC18F4620... hm, I haven't tried the MBSID application on this derivative for a long time - which MIOS release are you using, and which firmware version?Best Regards, Thorsten.I'm using MIOS 1.9c. I have to check the firmware version...I'm at work. I'm waiting for a PicKit 2 to come in the mail. When I get it I'm going to update everything and also try my other PIC chip. I have a 18F452 at home. Not sure if it's compatible with a 18F4620 or not though... Maybe I need to build a new core? Quote Link to comment Share on other sites More sharing options...
TK. Posted July 12, 2007 Report Share Posted July 12, 2007 Maybe I need to build a new core?Absolutely not - and I'm also sure, that you don't need to reburn the bootloader with a PIC programmer.MIOS and firmware can be easily uploaded via MIDI within a couple of seconds, thereafter your installation will be up-to-date again. :)I would recomment to install the latest MIOS version (MIOS V1.9e), and to try MIDIbox SID V1.7303 and MIDIbox SID V2.0beta4 (note: beta4 will be the last one which runs on a PIC18F4620 - with beta5 the 64k border has been reached)I propose this, as I cannot guarantee, that any application version will work with any MIOS version. I can only recomment: whenever you notice a strange behaviour, please always make sure that you are using the latest releases.Please let me know if you still notice random characters after the updateBest Regards, Thorsten. Quote Link to comment Share on other sites More sharing options...
jonkull Posted July 12, 2007 Author Report Share Posted July 12, 2007 OK. I'll run the updates when I get home and get back to you. Thanks for all the help. Quote Link to comment Share on other sites More sharing options...
jonkull Posted July 13, 2007 Author Report Share Posted July 13, 2007 Well I updated to 1.9e and 1.7303 and now all I get is a completely blank screen. No random characters or anything else. Haven't tried the 2.0 beta yet. Quote Link to comment Share on other sites More sharing options...
TK. Posted July 13, 2007 Report Share Posted July 13, 2007 So, you even don't get the MIOS boot message?Did you notice any error message during the code upload?Could you please upload the device_id_00.hex file of the change_id package? This ensures that the ID header is programmed correctly (and especially that the right LCD type is selected)Sidenote: under normal circumstances this doesn't need to be done. I only want to ensure that you are starting from a proper state. The PIC ID header is normaly programmed with the bootloader, and is never touched by any application - only exception: change_idBtw.: who did program the bootloader, and which version are you using?Best Regards, Thorsten. Quote Link to comment Share on other sites More sharing options...
TK. Posted July 15, 2007 Report Share Posted July 15, 2007 Did you solve the issue meanwhile?If not we could arrange a chat - many things can be clarified faster when we are talking directlyBest Regards, Thorsten. Quote Link to comment Share on other sites More sharing options...
jonkull Posted July 16, 2007 Author Report Share Posted July 16, 2007 So, you even don't get the MIOS boot message?Did you notice any error message during the code upload?Could you please upload the device_id_00.hex file of the change_id package? This ensures that the ID header is programmed correctly (and especially that the right LCD type is selected)Sidenote: under normal circumstances this doesn't need to be done. I only want to ensure that you are starting from a proper state. The PIC ID header is normaly programmed with the bootloader, and is never touched by any application - only exception: change_idBtw.: who did program the bootloader, and which version are you using?Best Regards, Thorsten.Sorry I was out most of the weekend. I didn't see any error messages...the upload appeared to go correctly. I'll try the device_id.hex tonight and see what happens. I don't remember the bootloader version (1.9c maybe)...it was whatever was current back in Nov. Now that I have a new PicKit 2 I'm going to reflash the PIC with the current bootloader and see if that helps. In the meantime I'm going to reinvestigate shorts. I noticed an IC with a bent pin that looked like it was seated properly but wasn't. That didn't fix the issue with the LCD though. I wish I had a way to test the LCD itself...maybe it's defective and I'm wasting time with everything else. In either cas the MBSid is playable and controllable via midi...I just have no display which is an annoyance but not the end of the world. Quote Link to comment Share on other sites More sharing options...
TK. Posted July 16, 2007 Report Share Posted July 16, 2007 Hope that you get it solved! By swapping the J15 socket (unintentionally of course), a LCD can be fried very easily, and one possible effect are random characters. But they normaly don't look like normal characters anymore, sometimes one or two pixel lines are missing, sometimes pixels are flickering.Best Regards, Thorsten (destroyed about 4..5 LCDs in the last years) Quote Link to comment Share on other sites More sharing options...
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