Add support for DHT12.

Change DHT11 temperature resolution to 0.1 instead of 1.

Author: fanthos

DHT.cpp

@@ -38,7 +38,12 @@ float DHT::readTemperature(bool S, bool force) {
   if (read(force)) {
     switch (_type) {
     case DHT11:
+    case DHT12:
       f = data[2];
+      f += (data[3] & 0x0f) * 0.1;
+      if (data[2] & 0x80) {
+        f *= -1;
+      }
       if(S) {
         f = convertCtoF(f);
       }
@@ -74,7 +79,8 @@ float DHT::readHumidity(bool force) {
   if (read()) {
     switch (_type) {
     case DHT11:
-      f = data[0];
+    case DHT12:
+      f = data[0] + data[1] * 0.1;
       break;
     case DHT22:
     case DHT21:

DHT.h

@@ -30,6 +30,7 @@ written by Adafruit Industries
 
 // Define types of sensors.
 #define DHT11 11
+#define DHT12 12
 #define DHT22 22
 #define DHT21 21
 #define AM2301 21

DHT_U.cpp

@@ -37,6 +37,9 @@ void DHT_Unified::setName(sensor_t* sensor) {
     case DHT11:
       strncpy(sensor->name, "DHT11", sizeof(sensor->name) - 1);
       break;
+    case DHT12:
+      strncpy(sensor->name, "DHT12", sizeof(sensor->name) - 1);
+      break;
     case DHT21:
       strncpy(sensor->name, "DHT21", sizeof(sensor->name) - 1);
       break;
@@ -57,6 +60,9 @@ void DHT_Unified::setMinDelay(sensor_t* sensor) {
     case DHT11:
       sensor->min_delay = 1000000L;  // 1 second (in microseconds)
       break;
+    case DHT12:
+      sensor->min_delay = 2000000L;  // 1 second (in microseconds)
+      break;
     case DHT21:
       sensor->min_delay = 2000000L;  // 2 seconds (in microseconds)
       break;
@@ -105,6 +111,11 @@ void DHT_Unified::Temperature::getSensor(sensor_t* sensor) {
       sensor->min_value   = 0.0F;
       sensor->resolution  = 2.0F;
       break;
+    case DHT12:
+      sensor->max_value   = 60.0F;
+      sensor->min_value   = -20.0F;
+      sensor->resolution  = 0.5F;
+      break;
     case DHT21:
       sensor->max_value   = 80.0F;
       sensor->min_value   = -40.0F;
@@ -159,6 +170,11 @@ void DHT_Unified::Humidity::getSensor(sensor_t* sensor) {
       sensor->min_value   = 20.0F;
       sensor->resolution  = 5.0F;
       break;
+    case DHT12:
+      sensor->max_value   = 95.0F;
+      sensor->min_value   = 20.0F;
+      sensor->resolution  = 5.0F;
+      break;
     case DHT21:
       sensor->max_value   = 100.0F;
       sensor->min_value   = 0.0F;