From 6dec421b164b8093c18182f4413021c34a7f53f7 Mon Sep 17 00:00:00 2001
From: Petr Kracik <petrkr@petrkr.net>
Date: Tue, 7 Apr 2026 16:32:05 +0200
Subject: [PATCH] Added SHT3x temp sensor support

---
 platformio.ini                                |  2 ++
 .../sensors/EnvironmentSensorManager.cpp      | 31 +++++++++++++++++++
 .../sensors/EnvironmentSensorManager.h        |  1 +
 3 files changed, 34 insertions(+)

diff --git a/platformio.ini b/platformio.ini
index 5f722e8923..5946b35fe3 100644
--- a/platformio.ini
+++ b/platformio.ini
@@ -125,6 +125,7 @@ build_flags =
   -D ENV_INCLUDE_BME280=1
   -D ENV_INCLUDE_BMP280=1
   -D ENV_INCLUDE_SHTC3=1
+  -D ENV_INCLUDE_SHT3X=1
   -D ENV_INCLUDE_SHT4X=1
   -D ENV_INCLUDE_LPS22HB=1
   -D ENV_INCLUDE_INA3221=1
@@ -144,6 +145,7 @@ lib_deps =
   adafruit/Adafruit BME280 Library @ ^2.3.0
   adafruit/Adafruit BMP280 Library @ ^2.6.8
   adafruit/Adafruit SHTC3 Library @ ^1.0.1
+  sensirion/Sensirion I2C SHT3x @ ^1.0.1
   sensirion/Sensirion I2C SHT4x @ ^1.1.2
   arduino-libraries/Arduino_LPS22HB @ ^1.0.2
   adafruit/Adafruit MLX90614 Library @ ^2.1.5
diff --git a/src/helpers/sensors/EnvironmentSensorManager.cpp b/src/helpers/sensors/EnvironmentSensorManager.cpp
index 62980f25e7..ab04d0e7a9 100644
--- a/src/helpers/sensors/EnvironmentSensorManager.cpp
+++ b/src/helpers/sensors/EnvironmentSensorManager.cpp
@@ -50,6 +50,12 @@ static Adafruit_BMP280 BMP280(TELEM_WIRE);
 static Adafruit_SHTC3 SHTC3;
 #endif
 
+#if ENV_INCLUDE_SHT3X
+#define TELEM_SHT3X_ADDRESS 0x44  //0x44 - 0x45
+#include <SensirionI2cSht3x.h>
+static SensirionI2cSht3x SHT3X;
+#endif
+
 #if ENV_INCLUDE_SHT4X
 #define TELEM_SHT4X_ADDRESS 0x44  //0x44 - 0x46
 #include <SensirionI2cSht4x.h>
@@ -234,6 +240,19 @@ bool EnvironmentSensorManager::begin() {
   }
   #endif
 
+#if ENV_INCLUDE_SHT3X
+  SHT3X.begin(*TELEM_WIRE, TELEM_SHT3X_ADDRESS);
+  uint16_t status = 0;
+  int16_t sht3x_error;
+  sht3x_error = SHT3X.readStatusRegister(status);
+  if (sht3x_error == 0) {
+    MESH_DEBUG_PRINTLN("Found SHT3X at address: %02X", TELEM_SHT3X_ADDRESS);
+    SHT3X_initialized = true;
+  } else {
+    SHT3X_initialized = false;
+    MESH_DEBUG_PRINTLN("SHT3X was not found at I2C address %02X", TELEM_SHT3X_ADDRESS);
+  }
+  #endif
 
   #if ENV_INCLUDE_SHT4X
   SHT4X.begin(*TELEM_WIRE, TELEM_SHT4X_ADDRESS);
@@ -411,6 +430,18 @@ bool EnvironmentSensorManager::querySensors(uint8_t requester_permissions, Cayen
     }
     #endif
 
+    #if ENV_INCLUDE_SHT3X
+    if (SHT3X_initialized) {
+      float sht3x_humidity, sht3x_temperature;
+      int16_t sht3x_error;
+      sht3x_error = SHT3X.measureSingleShot(REPEATABILITY_MEDIUM, false, sht3x_temperature, sht3x_humidity);
+      if (sht3x_error == 0) {
+        telemetry.addTemperature(TELEM_CHANNEL_SELF, sht3x_temperature);
+        telemetry.addRelativeHumidity(TELEM_CHANNEL_SELF, sht3x_humidity);
+      }
+    }
+    #endif
+
     #if ENV_INCLUDE_SHT4X
     if (SHT4X_initialized) {
       float sht4x_humidity, sht4x_temperature;
diff --git a/src/helpers/sensors/EnvironmentSensorManager.h b/src/helpers/sensors/EnvironmentSensorManager.h
index 32413ebc03..a8deaf1f0d 100644
--- a/src/helpers/sensors/EnvironmentSensorManager.h
+++ b/src/helpers/sensors/EnvironmentSensorManager.h
@@ -19,6 +19,7 @@ class EnvironmentSensorManager : public SensorManager {
   bool LPS22HB_initialized = false;
   bool MLX90614_initialized = false;
   bool VL53L0X_initialized = false;
+  bool SHT3X_initialized = false;
   bool SHT4X_initialized = false;
   bool BME680_initialized = false;
   bool BMP085_initialized = false;