--- 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;