c0nsumer Posted May 6, 2006 Report Share Posted May 6, 2006 Hey everyone. The other night I finished building a PIC burner based on TK's schematic, but I can't seem to make it work. I'm curious if anyone has any suggestions or has seen similar problems... First off, I laid out a new PCB and left off the power supply, as I can just use my benchtop one for it.The problem I am having is that the P18 software fails to recognize the programmer nor a PIC in it. However, I'm able to turn VPP, VDD, etc on and off (using both P8 PBrennerTester) and everything seems to work properly. I've triple-checked the board against the schematic and everything seems to match up.The machine I am trying to use is a Windows XP SP2 box from which (to be certain it wasn't one of them) I've removed all print drivers from. I've also tried the port in both standard parallel and ECP mode with no luck.Might any of you have any suggestions for other things to try?Thanks!-Steve Quote Link to comment Share on other sites More sharing options...
raphael Posted May 6, 2006 Report Share Posted May 6, 2006 The problem I am having is that the P8 software ...I assume you mean P18.However, I'm able to turn VPP, VDD, etc on and off (using both P8 PBrennerTester) and everything seems to work properly.Does the field "Daten Feedback" light up, if you switch on "Datenleitung ein"?Hove you done the "Kompatibilitätstest" described in the P18 help file?--> If you put a 100Ohm resistor between pin 2 and 10 of the parallel port instead of the burner, P18 should find a burner.Raphael Quote Link to comment Share on other sites More sharing options...
c0nsumer Posted May 6, 2006 Author Report Share Posted May 6, 2006 I assume you mean P18.Yes, heh. Sorry. I wrote this right after waking up... I've also corrected it in the original post.Does the field "Daten Feedback" light up, if you switch on "Datenleitung ein"?'Daten Feedback' is constantly checked (I think this is what you mean) regardless of the state of 'Datenleitung ein'. Nor can I uncheck it.Hove you done the "Kompatibilitätstest" described in the P18 help file?--> If you put a 100Ohm resistor between pin 2 and 10 of the parallel port instead of the burner, P18 should find a burner.Hrm, I must have missed this. I also have to apologize, as my Deutsch is not very good. I'm getting by with Babelfish and the memory of classes ~10 years ago. Anyway, I tried this and P18 still doesn't find a burner. I've also tried checking the box in the port's settings (in Device Manager) to be an LPT port, that didn't help. Then I tried the driver from UserPort.zip (found here) both in compatibility mode and natively and that didn't work either.At this point I think it's a problem on the PC. I'll have to dig into it some more...-Steve Quote Link to comment Share on other sites More sharing options...
TK. Posted May 6, 2006 Report Share Posted May 6, 2006 'Daten Feedback' is constantly checkedalright - this means that there is a problem with reading back the data line. You can follow back this line from PIC pin RB7 to LPT pin 10. You could use your multimeter in order to check the voltage levels when the data line is set to 0 (=0V) and 1 (=5V)Best Regards, Thorsten. Quote Link to comment Share on other sites More sharing options...
c0nsumer Posted May 6, 2006 Author Report Share Posted May 6, 2006 Well, it turns out that I've got a bad 25 pin cable. When I would clamp it in place and test the cable, everything seemed to work fine. However, if I move the cable there are intermittant drops in continuity. So, I think that this is the cause of the problem right now.I decided to check this after P18 was able to detect the programmer a few times, but then suddenly wasn't able to.I only have this DB25 M-M cable, so I'm next going to replace the header on the PIC Burner with a female one and try with another cable I have here. And yes, that other cable tests good. Quote Link to comment Share on other sites More sharing options...
c0nsumer Posted May 8, 2006 Author Report Share Posted May 8, 2006 Okay, some more info:Today I acquired a new fully working DB25 cable, but the problem still isn't resolved. P18 still doesn't recognize the burner.I've noticed that the aforementioned documentation says to use a 100? resistor between pins 2 and 10 to simulate a burner. This works great. However, I have noticed that between pins 2 and 10 on the burner itself there is a resistance of 1.023k? when no PIC is inserted. I've checked again, and my schematic matches the PIC Burner one.Perhaps somehow the 74HC14 I've used isn't quite compatible? The data sheet for it can be found here. Also, the schematic I made (and laid out the PCB from) can be seen here in PNG form.I'm not sure what to say... I can't help but think I screwed something up, but I really don't know what at this point.I'm still not sure why P18 was able to recognize the burner a few times yesterday. At that point it seemed like the faulty cable was completely to blame, but now that's clearly not the case. Quote Link to comment Share on other sites More sharing options...
raphael Posted May 8, 2006 Report Share Posted May 8, 2006 I have noticed that between pins 2 and 10 on the burner itself there is a resistance of 1.023k? when no PIC is insertedResistance doesn`t matter here. Please check the Voltages (against GND) of the Data In and Data Out lines when "Datenleitung ein" is set to 0 and to 1 (As Thosrten already suggested!).Raphael Quote Link to comment Share on other sites More sharing options...
c0nsumer Posted May 8, 2006 Author Report Share Posted May 8, 2006 Values are as described here:[table][tr][td](In VDC)[/td][td]Unchecked[/td][td]Checked[/td][/tr][tr][td]In[/td][td]0.104[/td][td]3.341[/td][/tr][tr][td]Out[/td][td]4.999[/td][td]4.999[/td][/tr][/table]My current thought is that one of the schmitt triggers in the 74HC14 isn't working because I overheated the IC.Does this sound accurate? I'll replace it when I get home and see...Thanks very much. :)-Steve Quote Link to comment Share on other sites More sharing options...
raphael Posted May 8, 2006 Report Share Posted May 8, 2006 My current thought is that one of the schmitt triggers in the 74HC14 isn't working because I overheated the ICSounds plausible. Quote Link to comment Share on other sites More sharing options...
c0nsumer Posted May 8, 2006 Author Report Share Posted May 8, 2006 Sounds plausible.I'll give it a try when I get home. Normally I don't socket all ICs, and I haven't had a problem in the past. I'll replace it with a socket and a spare part later this evening.Thanks again for the help. Quote Link to comment Share on other sites More sharing options...
c0nsumer Posted May 8, 2006 Author Report Share Posted May 8, 2006 Well, after replacing one of the 74HC14's with a socket and a spare rule out a burnt chip, I'm now having different problems. I replaced the 74HC14 to which the DATA lines are connected (IC4 in this schematic) and now Data Out (Pin 10 on the DB25) switches between ~0VDC and 5VDC about once per second. This even happens without the parallel port cable connected.So, at this point I think I should probably assume that I've either burnt out the other 74HC14 as well, or that I keep missing something in my layout of the board.Good thing there's an ICD2 clone on the way via eBay...< sigh >-Steve Quote Link to comment Share on other sites More sharing options...
TK. Posted May 9, 2006 Report Share Posted May 9, 2006 Hope that you don't fry your SIDs in the same way :-/Best Regards, Thorsten. Quote Link to comment Share on other sites More sharing options...
c0nsumer Posted May 9, 2006 Author Report Share Posted May 9, 2006 Hope that you don't fry your SIDs in the same way :-/Hehe, thanks. :)Those will definitely be socketed. I'm really not sure where I went wrong, because this is the first time I've ever fried an IC. I feel like quite a fool for it. I've mounted and desoldered plenty of parts in the past without problem, too. Maybe I accidently heated the parts for too long while soldering the top side of the board. (Yes, I'd made a quickly laid out double-sided board because I had the material and was being lazy.)I'm really not sure why it happened. Ah well, I'll be certain to be more careful about about it in the future, and maybe socket more things...Ah well... I should have the replacements on Friday. The prototype PCBs are coming Thursday, so everything seems like it's going ahead... Quote Link to comment Share on other sites More sharing options...
c0nsumer Posted May 14, 2006 Author Report Share Posted May 14, 2006 By the way, thanks for the help on this. Turns out the problem was one cooked IC and my failing to solder the socket on the top side of the board. (Double-sided home-made PCB.)That's what I get for trying to work on this while half asleep... Quote Link to comment Share on other sites More sharing options...
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