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Helyos
Joined: 22 Oct 2003
Posts: 22
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| jejejeje |
 Posted: Wed May 19, 2004 8:04 am |
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jejejeje Yes, it works. That isnīt the problem, forget the transistors 
The problem is in MCLR (or that I think  |
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Guest
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| I'm happy that I'm not the only one :-) |
| Posted: Wed May 19, 2004 5:18 pm |
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| frankb wrote: | Where is the current limiting resistor between the base of Q1 and RA4? If there is one, I haven't found it anywhere on your schematic. Now you're telling us that although the transistor is drawn incorrectly we should understand how it works anyway. Ohhhhh I need to go put something strong in my coffee.  |
This guy has to be taking something strong. If he wants to convince me that a PNP with the collector to V+ can be turned on by an open collector Pin_ A4 I think I'v ehave to also have something stringer in my coffee...
This thread has seen all sort of claims yet I feel we are not getting the truth !
It's a crap schematic ( that's not an insult, it's a statement of FACT) and I feel it has contributed to his problems.
Now has replied and claims it's the MCLR .... well WHAT is wrong with the MCLR on his deisgn.... !&)&&()*& |
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Guest
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| Re: Use the data sheet |
| Posted: Wed May 19, 2004 5:27 pm |
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Frank,
Well this is a first. He claims to use a symblol because a pins out is wrong and that it's supposed to work anyway..
A resistor would be needed if PIN_A4 could drive some current. All Pin_A4 can do is sink current....
I started of by thinking this guy was serious, know I'm sorry to have wasted this much time on this thread.
He does not take advice, and now comes with a magical statement "it works and the problem is in MCLR" excuse me but please tell us what the problem is.... ! |
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Helyos
Joined: 22 Oct 2003
Posts: 22
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| And what is the problem??? |
| Posted: Thu May 20, 2004 6:17 am |
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I want to know, what is the problem?
Do you have any problem with my question?
I have a problem, I ask your help. Iīm very serious. Iīm asking about a problem with the reset and the MCLR, and you answer me about the transistors. I tell (and repeat) that donīt look the transistors, the transistors arenīt connected, forget them!!!
I repeated that several times, but you insist in the transistors, and anybody solved the problem. Who are serious???
I have this problem, mi circuit if I power up, it works fine (the MCLR has a 10K resistor to 5V), but if I tie MCLR with ground (with a resistor of 100 Ohms as described in datasheet) I do a normal reset it resets but doesnīt restart the execution. I have to power off/on to reset. This only happens in the PCB, if I mount the circuit in a test board (wired) it resets, fine, but in the printed circuit not. Why???
I describe my problem, if you know and want help me you are serious and answer the cuestion or try find solutions asking me more information... (that is I try to do when I want help another persons in the things that I know) but donīt tell me that I am not serious. Iīm trying answer all your questions with accuracy to get, with the help of all persons in this forum, get a solutions.
Now... you can help to solve this problem?
Thanks to all for your time and effort. |
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Guest
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| Re: And what is the problem??? |
| Posted: Thu May 20, 2004 7:03 am |
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The fact that so many people have spent time and repeatly told you you MUST HAVE A WIRING PROBLEM shows that we all are serious in trying to help you, many have given good advice, which you seem to ignore.
You tell us yourself the hand wired board WORKS.... Well we cannot debug your PCB, and as I have constantly told you your approach to schematic drawing is you main source of "SELF INFLICTED PROBLEMS" . That is confirmed by your statement that you are wlling to use a transistor symbol that is not correct because of some pinout issue (which I still don't understand).
As several people have tried to tell you, pulling MCLR low WORKS, this is confirmed by YOU in that you tell us your handwired board works OK.... Issue CLOSED.
Time for you to get out the Ohm meter and trace your circuit, we can't do that for you....
Good luck and I hope you find the problem. |
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Helyos
Joined: 22 Oct 2003
Posts: 22
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| Guest... |
| Posted: Thu May 20, 2004 7:25 am |
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I think you donīt understand this yet...
The PCB Is correct, all connections are good. I took the polymeter and tested all. All is equals than in the hand wired board. I repeat that I donīt understand that, for that reason I ask for help and share my design, if anybody knows or saw something that seems this situation... |
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Guest
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| Issue CLOSED |
| Posted: Thu May 20, 2004 4:00 pm |
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| There is nothing more to say. Issue CLOSED |
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Helyos
Joined: 22 Oct 2003
Posts: 22
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| ???? jejeje |
| Posted: Thu May 20, 2004 4:48 pm |
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Who are you to close an issue, "guest"? 
You must speak only for yourself, if you donīt like read this topic, donīt read it
Iīm sure that we can solve this problem without you
Thank you very much for your shallow help |
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rwyoung
Joined: 12 Nov 2003
Posts: 563
Location: Lawrence, KS USA
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| Re: Guest... |
| Posted: Thu May 20, 2004 6:56 pm |
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| Helyos wrote: | I think you donīt understand this yet...
The PCB Is correct, all connections are good. I took the polymeter and tested all. All is equals than in the hand wired board. I repeat that I donīt understand that, for that reason I ask for help and share my design, if anybody knows or saw something that seems this situation... |
Helyos -
When you are fresh (or better yet, have another person) check one more time to be sure that there is not an accidental short circuit or open circuit in your board. Don't restrict your testing to just the MCLR pin. Look around a bit more. If the board is only 1 or 2 layers and without solid ground plane, hold it up to a strong light and use at least 5x magnifying lense to look closely at the board. I have seen many boards with manufacturing defects such as an eyelash fell onto the films before the resist was exposed. Likewise I have seen "mousebites" in traces where they over-etched or had an impurity in the copper causing an open circuit. I have seen problems with plated-through holes where because of poor drilling the trace into the pad was cut completely and so never bonded to the hole lining during plating.
Lots of things can go wrong during production. If you got all the boards made at the same time it is likely they all have the same fault. Try lifting out the MCLR pin (if possible) and wire that circuit yourself up in the air, don't use the traces on the printed circuit board. 
Just to beat a dead horse, the style you are using for your schematic drawings is a bit hard to follow but it is your style and it would seem that most of the time you are the only one who needs to deal with it.
And if you are forced to intentionally misapply a library element (the infamous transistor) then perhaps it is time to fix the tools or replace them. The "its cheap" or "its free" argument doesn't work well when a tool could potentially cause so much grief and waste your valuable time, even your personal time if this is a hobby project. I try to think how much I would use a particular piece of software or hardware and then figure out its cost over time.
Anyway, stay calm and look for the simple explanations: board production fault (open or short), cold solder joint, wrong resistor value (magnitude errors are pretty common), polarity error (not on a resistor but you get the idea), missing or wrong valued bypass capacitors, wrong IC or IC orientation. You get the idea.
Happy hunting (by the way I can look at the hardware for you but you would have to ship it to me and this seems just too simple to warrant that action).
_________________
Rob Young
The Screw-Up Fairy may just visit you but he has crashed on my couch for the last month! |
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Helyos
Joined: 22 Oct 2003
Posts: 22
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| Thanks |
| Posted: Fri May 21, 2004 8:22 am |
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Thanks for your answers and ideas.
I can tell you that I forwarded the nets on the board thousand times, I took the polimeter and tested all points and pines, and all seems correct.
I made the boards in a lab, and I solder all components. Itīs very strange that I did the same mistake four times (I made 4 prototypes), but itīs possible. You are right, I will take this with calm... and I will verify all again (the lense is a very good idea) and try hunt the mistake.
Thank you very much.
Best regards |
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Haplo
Joined: 06 Sep 2003
Posts: 659
Location: Sydney, Australia
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| Posted: Fri May 21, 2004 8:33 am |
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| Actually the fact that all your 4 boards had the same problem suggests that you have a defective batch of boards. |
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Helyos
Joined: 22 Oct 2003
Posts: 22
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| Yes... |
| Posted: Fri May 21, 2004 1:37 pm |
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Yes, I think that I have a mistake in the design or in any electrical property of any component, in due I posted my electrical design.
I hope you could help me to find the mistake.
Thanks |
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Guest
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| Posted: Fri May 21, 2004 3:34 pm |
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ZZZZZZZZZ......ZZZZZZZZZZ.....ZZZZZZZZZZZ  |
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Helyos
Joined: 22 Oct 2003
Posts: 22
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| Perfect!!! |
| Posted: Sun May 23, 2004 5:31 pm |
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Yes, thanks everybody, problem solved.
The board is perfect, all works perfectly (included transistors and buzzer , the problem was in the bootloader, it had enabled the LVP and didnīt allow that my programs change it.
If you disable it, you never have the same problem that me 
Thank you very much
Best regards |
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Haplo
Joined: 06 Sep 2003
Posts: 659
Location: Sydney, Australia
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| Posted: Sun May 23, 2004 5:59 pm |
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PCM Programmer did suggest that the problem was in your bootloader...
So how come it didn't show up on your breadboard and only caused problem on the prototype boards? |
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