1. msdagiya

    Thread Starter New Member

    Apr 21, 2012

    I am powering my PIC from USB with 470 uF capacitots of 5 and 0 volts. I am also using 970 Ohm resistor for POR. with two seven segments connected. I programmed my PIC with ICSP. using this code:

    PROCESSOR 16f877a
    #include "p16f877a.inc"

    org 0x00
    movlw 0x00
    movwf TRISC
    movlw 0x00
    movwf PORTC
    movlw 0x00
    movwf TRISD
    movlw 0xFF
    movwf PORTD

    my seven sgment should show seven on display instead it shows one. some time random LEDs are glowing. some time none of the LED works. seems like PIC is not programmed properly. But I tried reprogramming it successfully. At least it shows program successful when I program it. Can any one tell me if I am missing any thing. I also have crystals with right capacitors. My power pins are connected properly. PLease help
  2. tshuck

    Well-Known Member

    Oct 18, 2012
    Telling us what you think you did does not help. Provide a proper schematic and we will have a place to start.

    Secondly, you are not doing a bank switch, meaning your TRIS setting is writing to the port instead.
  3. t06afre

    AAC Fanatic!

    May 11, 2009
    And also the configuration words(s) are not set. At least not in the code. Your code should also be placed in some endless loop. The errors you have done are quite common for beginners. Then working with PICs. A lot of reading in the datasheet are required