Mercurial > mbsePi-apps / changeset

--- a/thermferm/devices.c	Mon Mar 25 11:44:45 2024 +0100
+++ b/thermferm/devices.c	Mon Mar 25 17:14:56 2024 +0100
@@ -50,101 +50,88 @@
 int             dht11_temperature = -1;
 int             dht11_humidity = -1;
 int		dht11_state = DEVPRESENT_UNDEF;
-time_t		dht11_last = (time_t)0;
+time_t		dht11_next;
 
 
 
 /*
  * DHT11 sensor read.
+ * Called at 30 seconds interval if all is well.
+ * If last read was an error, the interval is 2 seconds.
  */
 void dht11Read(char *address)
 {
-    int         	tries = 5, temp, hum;
-    int			fd, rc, err;
-    char		buffer[25], *dhtpath = NULL;
+    int        	temp, hum;
+    int		fd, rc, err;
+    char	buffer[25], *dhtpath = NULL;
+
+    dht11_temperature = -1;
+    dht11_humidity = -1;
+    dht11_state = DEVPRESENT_UNDEF;
+    dhtpath = xstrcpy((char *)"/sys/bus/iio/devices/");
+    dhtpath = xstrcat(dhtpath, address);
+    dhtpath = xstrcat(dhtpath, (char *)"/in_temp_input");
+
+    fd = open(dhtpath, O_RDONLY);
+    if (fd < 0) {
+	/*
+	 * The sensor is gone.
+	 */
+	err = errno;
+	syslog(LOG_NOTICE, "DHT11 open temperature: %d %s", err, strerror(err));
+	free(dhtpath);
+	dht11_state = DEVPRESENT_NO;
+	return;
+    }
 
-    while (tries) {
+    rc = read(fd, buffer, 25);
+    if (rc == -1) {
+	err = errno;
+	if (err == 110) {
+		dht11_state = DEVPRESENT_NO;	/* Device is gone */
+	} else {
+		dht11_state = DEVPRESENT_ERROR;
+	}
+	syslog(LOG_NOTICE, "DHT11 read temperature: %d %s", err, strerror(err));
+    } else {
+	sscanf(buffer, "%d", &temp);
+	dht11_temperature = temp;
+	dht11_state = DEVPRESENT_YES;
+    }
+    close(fd);
+    free(dhtpath);
+    dhtpath = NULL;
 
-	dht11_temperature = -1;
-	dht11_humidity = -1;
-	dht11_state = DEVPRESENT_UNDEF;
+    /*
+     * Only read humidity if state is DEVPRESENT_YES
+     */
+    if (dht11_state == DEVPRESENT_YES) {
 	dhtpath = xstrcpy((char *)"/sys/bus/iio/devices/");
 	dhtpath = xstrcat(dhtpath, address);
-	dhtpath = xstrcat(dhtpath, (char *)"/in_temp_input");
+	dhtpath = xstrcat(dhtpath, (char *)"/in_humidityrelative_input");
 
 	fd = open(dhtpath, O_RDONLY);
-	if (fd < 0) {
-	    /*
-	     * The sensor is gone.
-	     */
-	    err = errno;
-	    syslog(LOG_NOTICE, "DHT11 open temperature: %d %s", err, strerror(err));
-	    free(dhtpath);
-	    dht11_state = DEVPRESENT_NO;
-	    goto retry;
-//	    break;
-	}
 	rc = read(fd, buffer, 25);
 	if (rc == -1) {
 	    err = errno;
 	    if (err == 110) {
-		dht11_state = DEVPRESENT_NO;	/* Device is gone */
-		break;
+		    dht11_state = DEVPRESENT_NO;
 	    } else {
-		dht11_state = DEVPRESENT_ERROR;
+		    dht11_state = DEVPRESENT_ERROR;
 	    }
-	    syslog(LOG_NOTICE, "DHT11 read temperature: %d %s", err, strerror(err));
-	    dht11_temperature = -1;
+	    syslog(LOG_NOTICE, "DHT11 read humidity: %d %s", err, strerror(err));
+	    dht11_temperature = -1;	/* Make invalid	*/
 	} else {
-	    sscanf(buffer, "%d", &temp);
-	    dht11_temperature = temp;
+	    sscanf(buffer, "%d", &hum);
+	    dht11_humidity = hum;
 	    dht11_state = DEVPRESENT_YES;
 	}
 	close(fd);
 	free(dhtpath);
 	dhtpath = NULL;
-
-	/*
-	 * Only read humidity if state is DEVPRESENT_YES
-	 */
-	if (dht11_state == DEVPRESENT_YES) {
-	    dhtpath = xstrcpy((char *)"/sys/bus/iio/devices/");
-	    dhtpath = xstrcat(dhtpath, address);
-	    dhtpath = xstrcat(dhtpath, (char *)"/in_humidityrelative_input");
-
-	    fd = open(dhtpath, O_RDONLY);
-	    rc = read(fd, buffer, 25);
-	    if (rc == -1) {
-	    	err = errno;
-		if (err == 110) {
-		    dht11_state = DEVPRESENT_NO;
-		    break;
-		} else {
-		    dht11_state = DEVPRESENT_ERROR;
-		}
-	    	syslog(LOG_NOTICE, "DHT11 read temperature: %d %s", err, strerror(err));
-	    	dht11_humidity = -1;
-	    } else {
-	    	sscanf(buffer, "%d", &hum);
-	    	dht11_humidity = hum;
-		dht11_state = DEVPRESENT_YES;
-	    }
-	    close(fd);
-	    free(dhtpath);
-	    dhtpath = NULL;
-	}
-
-	if (dht11_state == DEVPRESENT_YES) {
-	    break;
-	}
-retry:
-	if (tries > 0) {
-	    tries--;
-	    usleep(400000);
-	}
     }
 
-    syslog(LOG_NOTICE, "dht11 t:%d h:%d tries:%d state:%d", dht11_temperature, dht11_humidity, 6-tries, dht11_state);
+    syslog(LOG_NOTICE, "dht11 t:%d h:%d state:%d", dht11_temperature, dht11_humidity, dht11_state);
 }
 
 
@@ -762,6 +749,8 @@
     	syslog(LOG_NOTICE, "my_devices_loop: piHiPri(50) rc=%d", rc);
 #endif
 
+    dht11_next = time(NULL);
+
     /*
      * Set the temperature sensors to 12 bits resolution and write it in EEPROM
      */
@@ -932,10 +921,11 @@
 		case DEVTYPE_DHT:
 			/*
 			 * Don't read these to often, 2 seconds minimum delay.
-			 * But we use 30 seconds interval.
+			 * Delay 30 seconds if last update was successfull,
+			 * else delay 2 seconds.
 			 */
 			now = time(NULL);
-			if ((int)(now - dht11_last) > 30) {
+			if ((int)(now >= dht11_next)) {
 			    if (device->subdevice == 0) {
 				/* Read once during subdevice 0 */
 			    	dht11Read(device->address);
@@ -947,15 +937,17 @@
 			    	}
 				pthread_mutex_unlock(&mutexes[LOCK_DEVICES]);
 			    } else if (device->subdevice == 1) {
-				/* Data already present */
+				/* Data already present, valid or not. */
 				pthread_mutex_lock(&mutexes[LOCK_DEVICES]);
 				device->present = dht11_state;
 			    	if (dht11_state == DEVPRESENT_YES) {
 				    device->value = dht11_humidity;
 				    device->timestamp = time(NULL);
-			    	}
+				    dht11_next = now + 29;
+			    	} else {
+				    dht11_next = now + 1;
+				}
 				pthread_mutex_unlock(&mutexes[LOCK_DEVICES]);
-				dht11_last = now;	/* Okay for a new reading. */
 			    }
 			}
 			break;