Merge pull request #4321 from fmuntean/P014-SI70xx

[P014 si70xx] fixing support for htu21D

src/_P014_SI70xx.ino

@@ -146,6 +146,9 @@ boolean Plugin_014(uint8_t function, struct EventStruct *event, String& string)
 
     case PLUGIN_INIT:
     {
+      if (P014_I2C_ADDRESS == 0) {
+        P014_I2C_ADDRESS = SI70xx_I2C_ADDRESS; // Use default address if not (yet) set
+      }
       initPluginTaskData(event->TaskIndex, new (std::nothrow) P014_data_struct());
       P014_data_struct *P014_data = static_cast<P014_data_struct *>(getPluginTaskData(event->TaskIndex));
 

src/src/PluginStructs/P014_data_struct.cpp

@@ -180,12 +180,22 @@ bool P014_data_struct::update(uint8_t i2caddr, uint8_t resolution, uint8_t filte
           return true;
         }
 
-        if (!readTemperature(i2caddr,resolution)){
+        last_measurement_time = millis();
+
+        if (chip_id == CHIP_ID_HTU21D){
+          if (!I2C_write8(i2caddr,SI70xx_CMD_MEASURE_TEMP)) { //HTU21D can't read temperature from humidity measurement
+            addLog(LOG_LEVEL_ERROR,F("SI70xx: startConv Failed!"));
+            return false;
+          }
+          state = P014_state::Wait_for_temperature_samples;
+          return false;
+        }
+
+        if (!readTemperatureFromHumidity(i2caddr,resolution)){
           state = P014_state::Ready; //we go back to request the reading again
           return true;
         }
 
-        last_measurement_time = millis();
         if (chip_id == CHIP_ID_SI7013){
           if(!enablePowerForADC(i2caddr)){
             state = P014_state::Ready; //we go back to request the reading again
@@ -198,7 +208,20 @@ bool P014_data_struct::update(uint8_t i2caddr, uint8_t resolution, uint8_t filte
         return true;
     //break;
 
-    case P014_state ::RequestADC:
+    case P014_state::Wait_for_temperature_samples:
+        if (!timeOutReached(last_measurement_time + SI70xx_MEASUREMENT_DELAY)) {
+          return false;
+        }
+
+        if (!readTemperature(i2caddr,resolution)){
+          state = P014_state::Ready; //we go back to request the reading again
+          return true;
+        }
+
+        state = P014_state::New_Values_Available;
+        return true;
+
+    case P014_state::RequestADC:
         //make sure we wait for the power to stabilize
         if (!timeOutReached(last_measurement_time + SI70xx_MEASUREMENT_DELAY)) {
           return false;
@@ -504,7 +527,7 @@ bool P014_data_struct::readHumidity(uint8_t i2caddr, uint8_t resolution)
 
     // Comes back in three bytes, data(MSB) / data(LSB) / Checksum
     raw  = ((uint16_t) Wire.read()) << 8;
-    raw |= Wire.read();
+    raw |= Wire.read(); 
     uint8_t checksum = Wire.read();
 
 
@@ -533,12 +556,42 @@ bool P014_data_struct::readHumidity(uint8_t i2caddr, uint8_t resolution)
   return true;
 }
 
+bool P014_data_struct::readTemperature(uint8_t i2caddr, uint8_t resolution)
+{
+  uint16_t raw;
+  uint8_t bytes = Wire.requestFrom(i2caddr, 3u); //asking to read 3 bytes  
+  if ( bytes < 3 ) {
+    return false;
+  }
+
+  // Comes back in three bytes, data(MSB) / data(LSB) / Checksum
+  raw  = ((uint16_t) Wire.read()) << 8;
+  raw |= Wire.read();
+
+  uint8_t checksum = Wire.read();
+
+  // Check CRC of data received
+  if(checkCRC(raw, checksum) != 0) {
+    addLog(LOG_LEVEL_ERROR,F("SI70xx : checksum error!"));
+    return false;
+  }
+
+  temperature =  convertRawTemperature(raw & 0xFFFC,resolution);
+  return true;
+}
 
-bool P014_data_struct::readTemperature(uint8_t i2caddr, uint8_t resolution){
+bool P014_data_struct::readTemperatureFromHumidity(uint8_t i2caddr, uint8_t resolution){
   // Temperature
   //Request a reading
   uint16_t   raw = I2C_read16_reg(i2caddr,SI70xx_CMD_READ_TEMP_FROM_HUM);
 
+  // save value
+  temperature =  convertRawTemperature(raw,resolution);
+
+  return true;
+}
+
+int16_t P014_data_struct::convertRawTemperature(uint16_t raw, uint8_t resolution){
   // Convert raw value to Temperature (*100)
   // for 23.45C value will be 2345
   int16_t data =  ((17572 * (long)raw) >> 16) - 4685;
@@ -553,11 +606,7 @@ bool P014_data_struct::readTemperature(uint8_t i2caddr, uint8_t resolution){
     data *= 10;
   }
 
-  // save value
-  temperature =  data;
-
-  return true;
+  return data;
 }
 
-
 #endif // ifdef USES_P014

src/src/PluginStructs/P014_data_struct.h

@@ -8,7 +8,8 @@
 // ######################## Plugin 014 SI70xx I2C Temperature Humidity Sensor  ###########################
 // #######################################################################################################
 // 12-10-2015 Charles-Henri Hallard, see my projects and blog at https://hallard.me
-// 07-22-2022 MFD, Adding support for SI7013 with ADC 
+// 07-22-2022 MFD, Adding support for SI7013 with ADC
+// 10-28-2022 MFD, fixing support for HTU21D (as this sensor does not have the command read temperature from humidity) 
 
 
 // SI70xx Sensor resolution
@@ -55,6 +56,7 @@
 #define CHIP_ID_SI7013  13 //  0x0D=13=Si7013
 #define CHIP_ID_SI7020  20 //  0x14=20=Si7020
 #define CHIP_ID_SI7021  21 //  0x15=21=Si7021
+#define CHIP_ID_HTU21D  50 //  as measured by the plugin (the datasheet does not have this info)
 
 #define SI70xx_RESET_DELAY            50 //delay in miliseconds for the reset to settle down
 #define SI70xx_MEASUREMENT_TIMEOUT   100 
@@ -104,9 +106,11 @@ struct P014_data_struct : public PluginTaskData_base {
     bool    requestADC(uint8_t i2caddr);
     bool    readADC(uint8_t i2caddr, uint8_t filter_power);
     bool    readHumidity(uint8_t i2caddr, uint8_t resolution);
+    bool    readTemperatureFromHumidity(uint8_t i2caddr, uint8_t resolution);
     bool    readTemperature(uint8_t i2caddr, uint8_t resolution);
     bool    startInit(uint8_t i2caddr);
     bool    finalizeInit(uint8_t i2caddr, uint8_t resolution);
+    int16_t convertRawTemperature(uint16_t raw, uint8_t resolution);
 
 public:
    P014_data_struct();