BME680 support (experimental)

include/globals.h

@@ -47,11 +47,11 @@ typedef struct {
 } gpsStatus_t;
 
 typedef struct {
-  uint16_t temperature;
-  uint16_t pressure;
-  uint16_t humidity;
-  uint16_t gas_resistance;
-  uint16_t altitude;
+  float_t temperature;
+  float_t pressure;
+  float_t humidity;
+  float_t gas_resistance;
+  float_t altitude;
 } bmeStatus_t;
 
 // global variables

include/payload.h

@@ -39,6 +39,7 @@ public:
                  uint8_t reset1, uint8_t reset2);
   void addAlarm(int8_t rssi, uint8_t message);
   void addGPS(gpsStatus_t value);
+  void addBME(bmeStatus_t value);
   void addButton(uint8_t value);
 
 #if PAYLOAD_ENCODER == 1 // format plain

platformio.ini

@@ -6,10 +6,10 @@
 
 ; ---> SELECT TARGET PLATFORM HERE! <---
 [platformio]
-;env_default = generic
+env_default = generic
 ;env_default = ebox
 ;env_default = eboxtube
-env_default = heltec
+;env_default = heltec
 ;env_default = heltecv2
 ;env_default = ttgov1
 ;env_default = ttgov2

src/bme680read.cpp

@@ -47,15 +47,14 @@ void bme_loop(void *pvParameters) {
     if (!bme.performReading()) {
       ESP_LOGE(TAG, "BME680 read error");
       continue;
+    } else {
+      // read current BME data and buffer in global struct
+      bme_status.temperature = bme.temperature;
+      bme_status.pressure = bme.pressure / 100.0;
+      bme_status.humidity = bme.humidity;
+      bme_status.gas_resistance = bme.gas_resistance / 1000.0;
+      bme_status.altitude = bme.readAltitude(SEALEVELPRESSURE_HPA);
     }
-
-    // read BME data and cast to global struct
-    bme_status.temperature = (uint16_t)bme.temperature;
-    bme_status.pressure = (uint16_t)(bme.pressure / 100.0);
-    bme_status.humidity = (uint16_t)bme.humidity;
-    bme_status.gas_resistance = (uint16_t)(bme.gas_resistance / 1000.0);
-    bme_status.altitude = (uint16_t)bme.readAltitude(SEALEVELPRESSURE_HPA);
-
   } // end of infinite loop
 
   vTaskDelete(NULL); // shoud never be reached

src/hal/heltec.h

@@ -3,13 +3,9 @@
 
 #include <stdint.h>
 
-#define HAS_BME 1  // BME680 sensor on I2C bus (SDA=4/SCL=15); comment out if not present
-
 // Hardware related definitions for Heltec LoRa-32 Board
-
 #define HAS_LORA 1       // comment out if device shall not send data via LoRa
 #define CFG_sx1276_radio 1
-
 #define HAS_DISPLAY U8X8_SSD1306_128X64_NONAME_HW_I2C // OLED-Display on board
 #define HAS_LED (25) // white LED on board
 #define HAS_BUTTON (0) // button "PROG" on board

src/lmic_config.h

@@ -21,7 +21,8 @@
 
 //#define LMIC_USE_INTERRUPTS
 
-#define LMIC_ENABLE_DeviceTimeReq 1
+//time sync via LoRaWAN network, is not yet supported by TTN (LoRaWAN spec v1.0.3)
+//#define LMIC_ENABLE_DeviceTimeReq 1
 
 // 16 μs per tick
 // LMIC requires ticks to be 15.5μs - 100 μs long
@@ -40,7 +41,7 @@
 // enable more verbose output. Make sure that printf is actually
 // configured (e.g. on AVR it is not by default), otherwise using it can
 // cause crashing.
-#define LMIC_DEBUG_LEVEL 2
+#define LMIC_DEBUG_LEVEL 0
 
 // Enable this to allow using printf() to print to the given serial port
 // (or any other Print object). This can be easy for debugging. The

src/payload.cpp

@@ -93,6 +93,16 @@ void PayloadConvert::addGPS(gpsStatus_t value) {
 #endif
 }
 
+void PayloadConvert::addBME(bmeStatus_t value) {
+#ifdef HAS_BME
+  buffer[cursor++] = (byte)(value.temperature);
+  buffer[cursor++] = (byte)(value.pressure);
+  buffer[cursor++] = (byte)(value.humidity);
+  buffer[cursor++] = (byte)(value.gas_resistance);
+  buffer[cursor++] = (byte)(value.altitude);
+#endif
+}
+
 void PayloadConvert::addButton(uint8_t value) {
 #ifdef HAS_BUTTON
   buffer[cursor++] = value;
@@ -150,6 +160,16 @@ void PayloadConvert::addGPS(gpsStatus_t value) {
 #endif
 }
 
+void PayloadConvert::addBME(bmeStatus_t value) {
+#ifdef HAS_BME
+  writeUint8((byte)value.temperature);
+  writeUint8((byte)value.pressure);
+  writeUint8((byte)value.humidity);
+  writeUint8((byte)value.gas_resistance);
+  writeUint8((byte)value.altitude);
+#endif
+}
+
 void PayloadConvert::addButton(uint8_t value) {
 #ifdef HAS_BUTTON
   writeUint8(value);