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alarm house 16f877 ?

Discussion in 'Microcontrollers' started by seti75, Jul 10, 2009.

  1. seti75

    seti75 New Member

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  2. Chippie

    Chippie New Member

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    If you program the hex file into the 877, and wire up to the schema it should blink the led....
     
  3. seti75

    seti75 New Member

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    I do not know only c' is vpp, pgd, pgc I have just finished l' test without connected vpp, pgd, and pgc the led remains extinct, I believe that the 16f877 died!
     
  4. dave

    Dave New Member

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  5. blueroomelectronics

    blueroomelectronics Well-Known Member

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    That's why it's handy to keep a spare.
     
  6. seti75

    seti75 New Member

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    test 16f877 flash led with another program

    my 16f877 --->

    YouTube - clig 16f877

    I do not include/understand any more ! j" stays on my peak had died…

    .it is ok ?

    why it does not function with the lcd 2x16 ?
     
  7. blueroomelectronics

    blueroomelectronics Well-Known Member

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    Since the LED is flashing why would you assume the 16F877 is broken?
     
  8. be80be

    be80be Well-Known Member

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    I told you when you first posted your osc is not working right . Your using a 20mzh crystal on the bread board that don't always work as planned. You posted a picture where it made a bunch of squares but no words I have had that happen it was the OSC not coming to speed change your code to use the 4mhz crystal and the lcd will work
    on your 16f877
     
    Last edited: Jul 16, 2009
  9. seti75

    seti75 New Member

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    the 16f877 does not function with my lcd 2x16

    to see the post at the beginning.

    with the moin 10 programs tested, no n' functioned with the 16f877,

    the lcd is good since it was tested with the 16f84 and it functions perfectly

    be80be -->
    but j' board makes test with the lcd and the 16f877 with quartz of 4mhz and without quartz I n' board ever have any favorable result
     
    Last edited: Jul 16, 2009
  10. be80be

    be80be Well-Known Member

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    Your using a 4 mhz crystal with the 16f84 Your using a 20 mhz crystal with the 16f877
    When you tested the blink code what crystal did you use
     
  11. seti75

    seti75 New Member

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    4mhz flash led 16f877 ..... ..ok
    4mhz lcd 16f84.................... ..ok
    4mhz and 16f877 and lcd ....... not good
    20mhz and 16f877 and lcd ......not good
     
  12. be80be

    be80be Well-Known Member

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    This is how I do it. In this pic look at how the crystal resonator is placed [​IMG]

    They don't work good with jumper
     
    Last edited: Jul 16, 2009
  13. Chippie

    Chippie New Member

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    The original schematic used a 20Mhz xtal...
     
  14. be80be

    be80be Well-Known Member

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    chippie I no what it used did you look at the picture that OP posted the 20mhz crystal is hooked to the 16f877 with jumpers. The chips not osculating is what's wrong
    This is OP board look at osc [​IMG]
     
    Last edited: Jul 16, 2009
  15. Chippie

    Chippie New Member

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    Ah..sorry didnt realise you knew about the xtal....but yeah agree his setup isnt v.good

    Scoping the pins should tell whats going on...
     
  16. seti75

    seti75 New Member

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    Before opening the post (1) first one, I had made this alarm
    At the beginning the problém was the same ! Nothing on the lcd.
    It is for that that I post Voila the position of the quartz, and it was the Same thing

    my alarm Imageshack - quartz
     
    Last edited: Jul 16, 2009
  17. be80be

    be80be Well-Known Member

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    It's still the Osc not working I have had it happen. It's up to you to fix it.
    I have changed crystals and it worked fine. If I could fly over I bet I'd have it running
    in a sec.
     
  18. be80be

    be80be Well-Known Member

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    The blinking a led with the Watchdog Timer on a 16f877 will not tell you if the crystal
    is working
     
  19. seti75

    seti75 New Member

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    be80be , thank
    I thank all for your help .
    I leave this project because it will never work! One friends think that the program b' is not good.
    This program was on a French forum, but the one that he proposed it was not on his (her,its) program,
    the electronique pratique (review) practical do not propose any more the program.

    If you know an alarm with a lcd and the same possibility that that her(it) thank you for me proposed.
    I leave , the program which made me lose a lot of time(weather), if a person want to make tries...

    program ---> Free - Envoyez vos documents

    Imageshack - sanstitre1txf

    Imageshack - sanstitre3p

    Imageshack - sanstitre4i
    Imageshack - sanstitre5c
     
  20. blueroomelectronics

    blueroomelectronics Well-Known Member

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    Was this a school project?
     
  21. be80be

    be80be Well-Known Member

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    Well seti75 it's up[ to you but I don't think your problem is as hard to fix as you think.
    You can't test the oscillator with the code from blueroomelectronics He was using the wdt it would still blink if you pulled the crystal out and threw it away.I still say it's in that 20 mhz crystal your using
     

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