LaundrySorcery

commit f8e45147139fdf6ef42b23c8a8be4ed1dfffdb79
parent cc02190335a6465cfa1be235ba12f61502fa0bc0
Author: Dominik Schmidt <das1993@hotmail.com>
Date:   Fri,  8 Jun 2018 14:17:38 +0000

Implement polling instead of ISRs

This prevents preemption of our worker thread and hence assures that we don't get a lot of timing variance.
We used to run into that problem because when the time required to charge the capacitor was high, we would have a huge variance.

Diffstat:
src/laundrysorcery.c
 | 
28
+++++++++++++++++++++++-----

1 file changed, 23 insertions(+), 5 deletions(-)
diff --git a/src/laundrysorcery.c b/src/laundrysorcery.c
@@ -131,19 +131,24 @@ void edge(void) {
 		rising_edge();
 }
 
+unsigned long microseconds_since(struct timespec ts){
+	struct timespec now;
+	clock_gettime(CLOCK_MONOTONIC, &now);
+	return (unsigned long)(now.tv_sec - ts.tv_sec)*1000000 + (unsigned long)(now.tv_nsec - ts.tv_nsec)/1000;
+}
+
 
 int main(int argc, char **argv)
 {
 	wiringPiSetup () ;
 	pinMode (0, OUTPUT) ;
-	//pinMode (1, INPUT) ;
+	pinMode (1, INPUT) ;
 	if(argc != 2){
 		printf("Usage: %s </path/to/onfile>\n", argv[0]);
 		return 0;
 	}
 	on_file=argv[1];
 
-	wiringPiISR(1, INT_EDGE_BOTH, &edge);
 	digitalWrite (0, LOW);
 	delay(5);
 	digitalWrite (0, HIGH);
@@ -152,10 +157,23 @@ int main(int argc, char **argv)
 
 	char buffer[512];
 	const char* arr[]={buffer};
+	struct timespec secondtimer;
+	clock_gettime(CLOCK_MONOTONIC, &secondtimer);
 	while(1) {
-		delay(1000);
-		snprintf(buffer,sizeof(buffer),"%lu:%e:%e:%e:%e:%e:%d",(unsigned long)time(NULL),running_mean,g_off.mean,g_off.variance,g_on.mean,g_on.variance,on);
-		rrd_update_r("database.rrd", NULL, 1, arr);
+		while(digitalRead(1)==0){
+			;
+		}
+		rising_edge();
+		while(digitalRead(1)==1){
+			;
+		}
+		falling_edge();
+		if(microseconds_since(secondtimer)>1000000){
+		//delay(1000);
+			snprintf(buffer,sizeof(buffer),"%lu:%e:%e:%e:%e:%e:%d",(unsigned long)time(NULL),running_mean,g_off.mean,g_off.variance,g_on.mean,g_on.variance,on);
+			rrd_update_r("database.rrd", NULL, 1, arr);
+			clock_gettime(CLOCK_MONOTONIC, &secondtimer);
+		}
 	}
 	return 0;
 }