Add I2C temperature sensor LM75AD

6.0.0a
* Add support for I2C temperature sensor LM75AD (#2909)

sonoff/_releasenotes.ino

@@ -1,6 +1,7 @@
 /* 6.0.0a
  * Add CRC to Settings making future upgrades more fail-safe
  * Add support for uploading Sonoff Bridge firmware found in tools/fw_efm8bb1 folder build by Portisch using Web Gui File Upload (#2886)
+ * Add support for I2C temperature sensor LM75AD (#2909)
  * Add command RfRaw to control Portisch firmware features
  * Remove version 3, 4 and pre 5.2 settings auto-upgrade. See https://github.com/arendst/Sonoff-Tasmota/wiki/Upgrade#migration-path
  * Change default CFG_HOLDER from 0x20161209 to 4617 (=0x1209) - no impact on default upgrades

sonoff/user_config.h

@@ -263,6 +263,7 @@
   #define USE_SHT                                // Add I2C emulating code for SHT1X sensor (+1k4 code)
   #define USE_SHT3X                              // Add I2C code for SHT3x or SHTC3 sensor (+0k7 code)
   #define USE_HTU                                // Add I2C code for HTU21/SI7013/SI7020/SI7021 sensor (+1k5 code)
+  #define USE_LM75AD                             // Add I2C code for LM75AD sensor (+0k5 code)
   #define USE_BMP                                // Add I2C code for BMP085/BMP180/BMP280/BME280 sensor (+4k code)
 //    #define USE_BME680                           // Add additional support for BME680 sensor using Adafruit Sensor and BME680 libraries (+6k code)
   #define USE_SGP30                              // Add I2C code for SGP30 sensor (+1k1 code)

sonoff/xsns_26_lm75ad.ino

@@ -1,7 +1,7 @@
 /*
-  xdrv_26_lm75ad.ino - Support for I2C LM75AD Temperature Sensor
+  xsns_26_lm75ad.ino - Support for I2C LM75AD Temperature Sensor
 
-  Copyright (C) 2018  Theo Arends
+  Copyright (C) 2018  Andre Thomas and Theo Arends
 
   This program is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
@@ -21,7 +21,11 @@
 #ifdef USE_LM75AD
 
 /*********************************************************************************************\
- * LM75AD
+ * LM75AD - Temperature
+ *
+ * Docs at https://www.nxp.com/docs/en/data-sheet/LM75A.pdf
+ *
+ * I2C Address: 0x48 - 0x4F
 \*********************************************************************************************/
 
 #define LM75AD_ADDRESS1					0x48
@@ -56,7 +60,7 @@ void LM75ADDetect()
   }
   for (byte i = 0; i < sizeof(lm75ad_addresses); i++) {
     lm75ad_address = lm75ad_addresses[i];
-    if (I2cValidRead8(&buffer,lm75ad_address,LM75_CONF_REGISTER)) {
+    if (I2cValidRead8(&buffer, lm75ad_address, LM75_CONF_REGISTER)) {
       lm75ad_type = 1;
       snprintf_P(log_data, sizeof(log_data), S_LOG_I2C_FOUND_AT, "LM75AD", lm75ad_address);
       AddLog(LOG_LEVEL_DEBUG);
@@ -67,34 +71,37 @@ void LM75ADDetect()
 
 float LM75ADConvertTemp(uint16_t t) {
   float tmpt;
+
+  int16_t sign = 1;
   if (t & 0x8000) { // we are getting a negative temperature value
-    t=t<<1; // shift out the MSB
+    t = (~t) +0x20;
-    t=t>>6; // shift value into place (5 LSB not used + the MSB we shifted out to make it zero)
+    sign = -1;
-    tmpt=t*0.125*-1;
-  } else { // we're getting a positive value
-    t=t>>5; // shift value into place (5 LSB not used)
-    tmpt=t*0.125;
-  }
-  if (!isnan(tmpt) && Settings.flag.temperature_conversion) {
-    tmpt = tmpt * 1.8 + 32;  // Fahrenheit
   }
+  t = t >> 5; // shift value into place (5 LSB not used)
+  tmpt = ConvertTemp(sign * t * 0.125);
+
   return tmpt;
 }
 
 void LM75ADShow(boolean json)
 {
   if (lm75ad_type) {
-      char temperature[10];
+    char temperature[10];
-      uint16_t lm75ad_value = LM75ADGetTempRegister();
+
-      float t=LM75ADConvertTemp(lm75ad_value);
+    uint16_t lm75ad_value = LM75ADGetTempRegister();
-      dtostrfd(t, Settings.flag2.temperature_resolution, temperature);
+    float t = LM75ADConvertTemp(lm75ad_value);
-      if (json) {
+    dtostrfd(t, Settings.flag2.temperature_resolution, temperature);
-        snprintf_P(mqtt_data, sizeof(mqtt_data), PSTR("%s,\"LM75AD\":{\"" D_JSON_TEMPERATURE "\":%s}"), mqtt_data, temperature);
+
+    if (json) {
+      snprintf_P(mqtt_data, sizeof(mqtt_data), PSTR("%s,\"LM75AD\":{\"" D_JSON_TEMPERATURE "\":%s}"), mqtt_data, temperature);
+#ifdef USE_DOMOTICZ
+      if (0 == tele_period) DomoticzSensor(DZ_TEMP, temperature);
+#endif  // USE_DOMOTICZ
 #ifdef USE_WEBSERVER
-      } else {
+    } else {
-        snprintf_P(mqtt_data, sizeof(mqtt_data), HTTP_SNS_TEMP, mqtt_data, "LM75AD", temperature, TempUnit());
+      snprintf_P(mqtt_data, sizeof(mqtt_data), HTTP_SNS_TEMP, mqtt_data, "LM75AD", temperature, TempUnit());
 #endif  // USE_WEBSERVER
-      }
+    }
   }
 }