oscilloscope and pic

Discussion in 'Embedded Systems and Microcontrollers' started by aduri, Jan 5, 2013.

  1. aduri

    Thread Starter New Member

    Jan 5, 2013
    2
    0
    Hello friends,
    This is my first post in this interesting forum.

    I made a oscilloscope for pic from
    http://semifluid.com/2006/08/21/pic1...scope/#more-15
    I used a PIC18f4550 instead of a PI18F2550
    I try to load this flile .hex
    http://semifluid.com/wp-content/uplo...bootloader.hex
    generated by this CCS code
    http://semifluid.com/wp-content/uplo...o-bootloader.c

    I don't understand......
    Show only the positive part of a sine wave and it is positioned at the bottom.
    The frequency and the line of zero-crossing dont'works.

    Can you send me a other .hex generated by you with the annexed code.

    bye
    Antonio
     
  2. Markd77

    Senior Member

    Sep 7, 2009
    2,803
    594
    If you are trying to measure an AC voltage that goes above and below 0V then you will get the results you describe. It can also be bad for the PIC. You would need some input circuitry to make the wave fit between 0 and 5V.
     
  3. aduri

    Thread Starter New Member

    Jan 5, 2013
    2
    0
    Probably is so (I could use one op-amp) but in any case also with the offset to 2.5 V (set my generator) the dots is not positioned in half of the screen and the frequency and the trigger don't works.

    Thanks
    Antonio[​IMG]
     
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