problem to interface MCP23017(4 nos.) with PIC16F1527

Discussion in 'The Projects Forum' started by mthakor, Jul 17, 2013.

  1. mthakor

    Thread Starter New Member

    Jul 17, 2013
    Hi Friends,
    we are interfacing MCP23017(4 nos.) with PIC16F1527.
    Our target is scanning 64 keys with 4 port expander.
    I have disable the intrrupts.
    But when test push buttons continuously pressing on & off with 20 ms delay.
    But after some time my MCU goes hanged.
    Is anyone can suggest what i will try to overcome this problem.?
  2. Papabravo


    Feb 24, 2006
    I suggest you post a schematic, and your code.
    The most likely reason for a PIC (or any Harvard Architecture) machine to hang is waiting on a single condition that will never happen. In defensive programming you always need to test multiple conditions to exit from a loop.