From 9a5217bf90381e96d7de92348d49473511a348c9 Mon Sep 17 00:00:00 2001
From: Theo Arends <11044339+arendst@users.noreply.github.com>
Date: Mon, 19 Feb 2024 14:17:40 +0100
Subject: [PATCH] Add heatindex to BMP driver (#4771)

---
 tasmota/tasmota_support/support.ino         |  7 ++++++-
 tasmota/tasmota_xsns_sensor/xsns_09_bmp.ino | 14 +++++++++++++-
 2 files changed, 19 insertions(+), 2 deletions(-)

diff --git a/tasmota/tasmota_support/support.ino b/tasmota/tasmota_support/support.ino
index f6e3b6f55..42bdca5ad 100755
--- a/tasmota/tasmota_support/support.ino
+++ b/tasmota/tasmota_support/support.ino
@@ -860,6 +860,8 @@ float CalcTempHumToDew(float t, float h) {
 
 #ifdef USE_HEAT_INDEX
 float CalcTemHumToHeatIndex(float t, float h) {
+  if (isnan(h) || isnan(t)) { return NAN; }
+
   if (!Settings->flag.temperature_conversion) {                // SetOption8 - Switch between Celsius or Fahrenheit
     t = t * 1.8f + 32;                                         // Fahrenheit
   }
@@ -881,7 +883,10 @@ float CalcTemHumToHeatIndex(float t, float h) {
       hi += ((h - 85.0) * 0.1) * ((87.0 - t) * 0.2);
     }
   }
-  return (Settings->flag.temperature_conversion) ? hi : (hi - 32) / 1.8f;
+  if (!Settings->flag.temperature_conversion) {                // SetOption8 - Switch between Celsius or Fahrenheit
+    hi = (hi - 32) / 1.8f;                                     // Celsius
+  }
+  return hi;
 }
 #endif  // USE_HEAT_INDEX
 
diff --git a/tasmota/tasmota_xsns_sensor/xsns_09_bmp.ino b/tasmota/tasmota_xsns_sensor/xsns_09_bmp.ino
index b9ed27082..5dc0d7197 100644
--- a/tasmota/tasmota_xsns_sensor/xsns_09_bmp.ino
+++ b/tasmota/tasmota_xsns_sensor/xsns_09_bmp.ino
@@ -583,14 +583,23 @@ void BmpShow(bool json) {
       float f_dewpoint = CalcTempHumToDew(bmp_temperature, bmp_humidity);
       char dewpoint[33];
       dtostrfd(f_dewpoint, Settings->flag2.temperature_resolution, dewpoint);
+#ifdef USE_HEAT_INDEX
+      float f_heatindex = CalcTemHumToHeatIndex(bmp_temperature, bmp_humidity);
+      char heatindex[33];
+      dtostrfd(f_heatindex, Settings->flag2.temperature_resolution, heatindex);
+#endif  // USE_HEAT_INDEX
 #ifdef USE_BME68X
       char gas_resistance[33];
       dtostrfd(bmp_sensors[bmp_idx].bmp_gas_resistance, 2, gas_resistance);
 #endif  // USE_BME68X
 
       if (json) {
-        char json_humidity[80];
+        char json_humidity[100];
+#ifdef USE_HEAT_INDEX
+        snprintf_P(json_humidity, sizeof(json_humidity), PSTR(",\"" D_JSON_HUMIDITY "\":%s,\"" D_JSON_DEWPOINT "\":%s,\"" D_JSON_HEATINDEX "\":%s"), humidity, dewpoint, heatindex);
+#else
         snprintf_P(json_humidity, sizeof(json_humidity), PSTR(",\"" D_JSON_HUMIDITY "\":%s,\"" D_JSON_DEWPOINT "\":%s"), humidity, dewpoint);
+#endif  // USE_HEAT_INDEX
         char json_sealevel[40];
         snprintf_P(json_sealevel, sizeof(json_sealevel), PSTR(",\"" D_JSON_PRESSUREATSEALEVEL "\":%s"), sea_pressure);
 #ifdef USE_BME68X
@@ -631,6 +640,9 @@ void BmpShow(bool json) {
         if (bmp_sensors[bmp_idx].bmp_model >= 2) {
           WSContentSend_PD(HTTP_SNS_HUM, name, humidity);
           WSContentSend_PD(HTTP_SNS_DEW, name, dewpoint, TempUnit());
+#ifdef USE_HEAT_INDEX
+          WSContentSend_PD(HTTP_SNS_HEATINDEX, name, heatindex, TempUnit());
+#endif  // USE_HEAT_INDEX
         }
         WSContentSend_PD(HTTP_SNS_PRESSURE, name, pressure, PressureUnit().c_str());
         if (Settings->altitude != 0) {