oscillator problem

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  1. - 4th September 2010, 12:27 #1
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    Quote Originally Posted by Acetronics View Post
    did you clean the board carefully with acetone to wipe off any solder stripper ??? especially under the caps ...

    next step will be verify your caps value ( SMD not marked ...) and Xtal data ...

    may be could we have an eye on your program ??? ...

    Alain

    BTW ... could you try to run the PIC @ 10 mhz ( HS_OSC ) ... just to see if any life aboard.
    I did clean the board thoroughly with alcohol to get rid of flux, etc.

    Ive tried every cap value I have. At the moment I've actually replaced the SMD caps with 22pF thru-hole caps soldered onto the SMD pads as a test, but that didn't help either.

    Unfortunately I dont have data on my crystal. The place I bought it didn't supply data or a specific manufacturer/model number.

    When this started happening I reduced my program to a bare minimum to test if it is running. After trying 10mhz with HS_OSC (which didnt make a difference), the code im using is:

    Code:
    DEFINE OSC 10

ADCON1=%01111111

LCD_DB4         VAR PORTA.4
LCD_DB5         VAR PORTA.2
LCD_DB6         VAR PORTA.3
LCD_DB7         VAR PORTB.0
LCD_RS          VAR PORTA.0
LCD_E           VAR PORTA.1
LCD_Lines       CON 2    
LCD_DATAUS      CON 50 
LCD_COMMANDUS   CON 2000

INCLUDE "LCD_AnyPin.pbp"

PAUSE 200

LCDOUT $FE,1,$FE,2,"Hello World!"

END
    "I think fish is nice, but then I think that rain is wet, so who am I to judge?" - Douglas Adams
  2. - 4th September 2010, 12:38 #2
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    Try a simple BLINKY on a non ADC pin for a test.
    Tooo many things could be wrong with the other stuff.
    Dave
    Always wear safety glasses while programming.
  3. - 4th September 2010, 12:41 #3
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    Quote Originally Posted by Kamikaze47 View Post

    didnt make a difference), the code im using is:

    Code:
    DEFINE OSC 10
 
ADCON1=%01111111
 
LCD_DB4         VAR PORTA.4
LCD_DB5         VAR PORTA.2
LCD_DB6         VAR PORTA.3
LCD_DB7         VAR PORTB.0
LCD_RS          VAR PORTA.0
LCD_E           VAR PORTA.1
LCD_Lines       CON 2    
LCD_DATAUS      CON 50 
LCD_COMMANDUS   CON 2000
 
INCLUDE "LCD_AnyPin.pbp"
 
PAUSE 200
 
LCDOUT $FE,1,$FE,2,"Hello World!"
 
END
    Do you remember PORTA.4 is an open collector pin ... ???

    ... and you could use pause 500+ instead of 200. some displays are a bit lazy ...
    Last edited by Acetronics2; - 4th September 2010 at 12:44.
    ************************************************** ***********************
    Why insist on using 32 Bits when you're not even able to deal with the first 8 ones ??? ehhhhhh ...
    ************************************************** ***********************
    IF there is the word "Problem" in your question ...
    certainly the answer is " RTFM " or " RTFDataSheet " !!!
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  4. - 4th September 2010, 12:47 #4
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    Quote Originally Posted by Acetronics View Post
    Do you remember PORTA.4 is an open collector pin ... ???

    ... and you could use pause 500+ instead of 200. some displays are a bit lazy ...
    I added a pullup resistor to PORTA.4

    It's definitely the osc because if I leave it running for 15 mins or so it does eventually display "Hello World!" extremely slowly.
    "I think fish is nice, but then I think that rain is wet, so who am I to judge?" - Douglas Adams
  5. - 4th September 2010, 12:56 #5
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    Quote Originally Posted by Kamikaze47 View Post
    I added a pullup resistor to PORTA.4

    It's definitely the osc because if I leave it running for 15 mins or so it does eventually display "Hello World!" extremely slowly.
    I think so ... now.
    Xtals also can be a bit lazy ... depends on the " cut "

    don't you have a 12 or 16 Mhz Xtal ... ( I recently saw a 18F overclocked @ 80 Mhz !!! ... ) 48 Mhz is easy, 64 might work.

    Alain
    ************************************************** ***********************
    Why insist on using 32 Bits when you're not even able to deal with the first 8 ones ??? ehhhhhh ...
    ************************************************** ***********************
    IF there is the word "Problem" in your question ...
    certainly the answer is " RTFM " or " RTFDataSheet " !!!
    *****************************************
  6. - 4th September 2010, 13:09 #6
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    Quote Originally Posted by Acetronics View Post
    I think so ... now.
    Xtals also can be a bit lazy ... depends on the " cut "

    don't you have a 12 or 16 Mhz Xtal ... ( I recently saw a 18F overclocked @ 80 Mhz !!! ... ) 48 Mhz is easy, 64 might work.

    Alain
    I just replaced it with a 16mhz which is working but that could just be because of the heating up. The test will be leaving it for half an hour and see if it still works. I'll post again then
    "I think fish is nice, but then I think that rain is wet, so who am I to judge?" - Douglas Adams
  7. - 4th September 2010, 13:55 #7
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    it seems to be running happily at 64hmz

    i dont understand why since i tried 2 different 10mhz crystals
    "I think fish is nice, but then I think that rain is wet, so who am I to judge?" - Douglas Adams
  8. - 4th September 2010, 14:00 #8
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    Quote Originally Posted by Kamikaze47 View Post
    it seems to be running happily at 64hmz

    i dont understand why since i tried 2 different 10mhz crystals
    To be really quiet with that ...

    I only buy my Xtals from Farnell, now ... per 100, price is nice.

    Never more from a local dealer ...

    Alain
    ************************************************** ***********************
    Why insist on using 32 Bits when you're not even able to deal with the first 8 ones ??? ehhhhhh ...
    ************************************************** ***********************
    IF there is the word "Problem" in your question ...
    certainly the answer is " RTFM " or " RTFDataSheet " !!!
    *****************************************
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