Files
gpio-reader/examples/isr_debounce.c
2025-01-29 11:50:28 +01:00

116 lines
2.8 KiB
C

/*
* isr_debounce.c:
* Wait for Interrupt test program WiringPi >=3.13 - ISR method
*
*
*/
#include <stdio.h>
#include <string.h>
#include <errno.h>
#include <stdlib.h>
#include <wiringPi.h>
#include <time.h>
#define BOUNCETIME 300
#define TIMEOUT 10000
//*************************************
// BCM pins
// IRQpin : setup as input with internal pullup. Connected with push button to GND with 1K resistor in series.
// OUTpin : connected to a LED with 470 Ohm resistor in series to GND. Toggles LED with every push button pressed.
//*************************************
#define IRQpin 16
#define OUTpin 12
int toggle = 0;
/*
* myInterrupt:
*********************************************************************************
*/
static void wfi (unsigned int gpio, long long int timestamp) {
// struct timeval now;
long long int timenow, diff;
struct timespec curr;
if (clock_gettime(CLOCK_MONOTONIC, &curr) == -1) {
printf("clock_gettime error");
return;
}
timenow = curr.tv_sec * 1000000LL + curr.tv_nsec/1000L; // convert to microseconds
diff = timenow - timestamp;
printf("gpio BCM = %d, IRQ timestamp = %lld microseconds, timenow = %lld, diff = %lld\n", gpio, timestamp, timenow, diff);
if (toggle == 0) {
digitalWrite (OUTpin, HIGH) ;
toggle = 1;
}
else {
digitalWrite (OUTpin, LOW) ;
toggle = 0;
}
}
int main (void)
{
int major, minor;
long long int ret;
wiringPiVersion(&major, &minor);
printf("\nISR debounce test (WiringPi %d.%d)\n\n", major, minor);
wiringPiSetupGpio() ;
pinMode(IRQpin, INPUT);
// pull up/down mode (PUD_OFF, PUD_UP, PUD_DOWN) => down
pullUpDnControl(IRQpin, PUD_UP);
pinMode(OUTpin, OUTPUT);
digitalWrite (OUTpin, LOW) ;
// test waitForInterrupt
ret = waitForInterruptInit (IRQpin, INT_EDGE_FALLING);
if (ret < 0) {
printf("waitForInterruptInit returned error %d\n", ret);
pinMode(OUTpin, INPUT);
return 0;
}
printf("Testing waitForInterrupt IRQ @ GPIO%d, timeout is %d\n", IRQpin, TIMEOUT);
ret = waitForInterrupt(IRQpin, TIMEOUT, 0);
if (ret < 0) {
printf("waitForInterrupt returned error %lld\n", ret);
wiringPiISRStop (IRQpin) ;
pinMode(OUTpin, INPUT);
return 0;
}
else if (ret == 0) {
printf("waitForInterrupt timed out %lld\n\n", ret);
wiringPiISRStop (IRQpin) ;
}
else {
printf("waitForInterrupt: falling edge fired at %lld microseconds\n\n", ret);
wiringPiISRStop (IRQpin) ;
}
printf("Testing IRQ @ GPIO%d with trigger @ GPIO%d falling edge and bouncetime %d ms. Toggle LED @ OUTpin on IRQ.\n\n", IRQpin, IRQpin, BOUNCETIME, OUTpin);
printf("To stop program hit return key\n\n");
wiringPiISR (IRQpin, INT_EDGE_FALLING, &wfi, BOUNCETIME) ;
// sleep(30);
getc(stdin);
wiringPiISRStop (IRQpin) ;
pinMode(OUTpin, INPUT);
return 0 ;
}