On  7 Jul 97 at 22:07, Daniel Najemy wrote:

> Easy Question (for you pro's): I want to read a non-interrupt driven
> port on a PIC16C74 and detect a rising or falling edge.
...
> How could I implement this in C?

Hi Daniel,

here's are two functions (taken from an example program delivered
with the CCS C compiler):


void wait_for_low_to_high() {
   while(input(PIN_B1)) ;       /* if it's high, wait for a low */
   delay_us(3);                 /* account for fall time */
   while(!input(PIN_B1));       /* wait for signal to go high */
}

void wait_for_low() {
   delay_us(3);                 /* account for rise time */
   while(input(PIN_B1));        /* wait for signal to go low */
}

Regards,
Wolfgang

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