Support for BME280 sensor

code/espurna/config/prototypes.h

@@ -78,11 +78,13 @@ template<typename T> bool idbSend(const char * topic, unsigned char id, T payloa
 #if DS18B20_SUPPORT
 #include <OneWire.h>
 #endif
-
 #if PMSX003_SUPPORT
 #include <SoftwareSerial.h>
 #include <PMS.h>
 #endif
+#if BME280_SUPPORT
+#include <SparkFunBME280.h>
+#endif
 
 // -----------------------------------------------------------------------------
 // Utils

code/espurna/config/sensors.h

@@ -58,6 +58,24 @@
 #define SI7021_ADDRESS              0x40
 #endif
 
+//--------------------------------------------------------------------------------
+// BME280
+// Enable support by passing BME280_SUPPORT=1 build flag
+//--------------------------------------------------------------------------------
+
+#ifndef BME280_SUPPORT
+#define BME280_SUPPORT              0
+#endif
+
+#ifndef BME280_ADDRESS
+#define BME280_ADDRESS              0x76
+#endif
+
+#define BME280_MODE                 1       // 1 for forced mode, 3 for normal mode
+#define BME280_TEMPERATURE          1       // Oversampling for temperature (set to 0 to disable magnitude)
+#define BME280_HUMIDITY             1       // Oversampling for humidity (set to 0 to disable magnitude)
+#define BME280_PRESSURE             1       // Oversampling for pressure (set to 0 to disable magnitude)
+
 //--------------------------------------------------------------------------------
 // DS18B20 temperature sensor
 // Enable support by passing DS18B20_SUPPORT=1 build flag
@@ -206,7 +224,7 @@
 //--------------------------------------------------------------------------------
 
 #ifndef PMSX003_SUPPORT
-#define PMSX003_SUPPORT                 1
+#define PMSX003_SUPPORT                 0
 #endif
 
 #define PMS_RX_PIN                      13

code/espurna/sensor.ino

@@ -242,6 +242,11 @@ void sensorInit() {
         sensorRegister(new SI7021Sensor(SI7021_ADDRESS));
     #endif
 
+    #if BME280_SUPPORT
+        #include "sensors/BME280Sensor.h"
+        sensorRegister(new BME280Sensor(BME280_ADDRESS));
+    #endif
+
     #if ANALOG_SUPPORT
         #include "sensors/AnalogSensor.h"
         sensorRegister(new AnalogSensor(ANALOG_PIN));
@@ -261,7 +266,7 @@ void sensorInit() {
         #include "sensors/EmonADS1X15Sensor.h"
         sensorRegister(new EmonADS1X15Sensor(EMON_ADS1X15_I2C_ADDRESS, EMON_ADS1X15_ADS1115, EMON_ADS1X15_PORT_MASK, EMON_MAINS_VOLTAGE, EMON_ADS1X15_ADC_BITS, EMON_ADS1X15_REFERENCE_VOLTAGE, EMON_ADS1X15_CURRENT_RATIO));
     #endif
-    
+
     #if PMSX003_SUPPORT
         #include "sensors/PMSX003Sensor.h"
         sensorRegister(new PMSX003Sensor(PMS_RX_PIN, PMS_TX_PIN));

code/espurna/sensors/BME280Sensor.h

@@ -0,0 +1,170 @@
+// -----------------------------------------------------------------------------
+// BME280 Sensor
+// -----------------------------------------------------------------------------
+
+#pragma once
+
+#include "Arduino.h"
+#include "BaseSensor.h"
+#include <SparkFunBME280.h>
+
+#define BME280_ERROR_UNKNOW_CHIP    -1
+
+class BME280Sensor : public BaseSensor {
+
+    public:
+
+        BME280Sensor(unsigned char address = BME280_ADDRESS): BaseSensor() {
+
+            // Cache
+            _address = address;
+            _measurement_delay = bmeMeasurementTime();
+
+            #if BME280_TEMPERATURE > 0
+                ++_count;
+            #endif
+            #if BME280_HUMIDITY > 0
+                ++_count;
+            #endif
+            #if BME280_PRESSURE > 0
+                ++_count;
+            #endif
+
+            // Init
+            bme = new BME280();
+            bme->settings.commInterface = I2C_MODE;
+            bme->settings.I2CAddress = _address;
+            bme->settings.runMode = BME280_MODE;
+            bme->settings.tStandby = 0;
+            bme->settings.filter = 0;
+            bme->settings.tempOverSample = BME280_TEMPERATURE;
+            bme->settings.pressOverSample = BME280_PRESSURE;
+            bme->settings.humidOverSample = BME280_HUMIDITY;
+
+            // Fix when not measuring temperature, t_fine should have a sensible value
+            if (BME280_TEMPERATURE == 0) bme->t_fine = 100000; // aprox 20ºC
+
+            // Make sure sensor had enough time to turn on. BME280 requires 2ms to start up
+            delay(10);
+
+            // Check sensor correctly initialized
+            unsigned char response = bme->begin();
+            if (response == 0x60) {
+                _ready = true;
+            } else {
+                _error = BME280_ERROR_UNKNOW_CHIP;
+            }
+
+        }
+
+        // Descriptive name of the sensor
+        String name() {
+            char buffer[20];
+            snprintf(buffer, sizeof(buffer), "BME280 @ I2C (0x%02X)", _address);
+            return String(buffer);
+        }
+
+        // Descriptive name of the slot # index
+        String slot(unsigned char index) {
+            return name();
+        }
+
+        // Type for slot # index
+        magnitude_t type(unsigned char index) {
+            if (index < _count) {
+                _error = SENSOR_ERROR_OK;
+                unsigned char i = 0;
+                #if BME280_TEMPERATURE > 0
+                    if (index == i++) return MAGNITUDE_TEMPERATURE;
+                #endif
+                #if BME280_HUMIDITY > 0
+                    if (index == i++) return MAGNITUDE_HUMIDITY;
+                #endif
+                #if BME280_PRESSURE > 0
+                    if (index == i) return MAGNITUDE_PRESSURE;
+                #endif
+            }
+            _error = SENSOR_ERROR_OUT_OF_RANGE;
+            return MAGNITUDE_NONE;
+        }
+
+        // Pre-read hook (usually to populate registers with up-to-date data)
+        virtual void pre() {
+
+            if (!_ready) {
+                _error = BME280_ERROR_UNKNOW_CHIP;
+                return;
+            }
+
+            #if BME280_MODE == 1
+                bmeForceRead();
+            #endif
+
+        }
+
+        // Current value for slot # index
+        double value(unsigned char index) {
+
+            if (index < _count) {
+                _error = SENSOR_ERROR_OK;
+                unsigned char i = 0;
+                #if BME280_TEMPERATURE > 0
+                    if (index == i++) return bme->readTempC();
+                #endif
+                #if BME280_HUMIDITY > 0
+                    if (index == i++) return bme->readFloatHumidity();
+                #endif
+                #if BME280_PRESSURE > 0
+                    if (index == i) return bme->readFloatPressure() / 100;
+                #endif
+            }
+            _error = SENSOR_ERROR_OUT_OF_RANGE;
+            return 0;
+        }
+
+    protected:
+
+        unsigned long bmeMeasurementTime() {
+
+            // Measurement Time (as per BME280 datasheet section 9.1)
+            // T_max(ms) = 1.25
+            //  + (2.3 * T_oversampling)
+            //  + (2.3 * P_oversampling + 0.575)
+            //  + (2.4 * H_oversampling + 0.575)
+            //  ~ 9.3ms for current settings
+
+            double t = 1.25;
+            #if BME280_TEMPERATURE > 0
+                t += (2.3 * BME280_TEMPERATURE);
+            #endif
+            #if BME280_HUMIDITY > 0
+                t += (2.4 * BME280_HUMIDITY + 0.575);
+            #endif
+            #if BME280_PRESSURE > 0
+                t += (2.3 * BME280_PRESSURE + 0.575);
+            #endif
+
+            return round(t + 1); // round up
+
+        }
+
+        void bmeForceRead() {
+
+            // We set the sensor in "forced mode" to force a reading.
+            // After the reading the sensor will go back to sleep mode.
+            uint8_t value = bme->readRegister(BME280_CTRL_MEAS_REG);
+            value = (value & 0xFC) + 0x01;
+            bme->writeRegister(BME280_CTRL_MEAS_REG, value);
+
+            delay(_measurement_delay);
+
+        }
+
+        // ---------------------------------------------------------------------
+
+        BME280 * bme;
+        unsigned char _address;
+        unsigned long _measurement_delay;
+        bool _ready = false;
+
+};

code/platformio.ini

@@ -21,6 +21,7 @@ lib_deps =
     NtpClientLib
     OneWire
     Brzo I2C
+    SparkFun BME280
     https://github.com/krosk93/espsoftwareserial#a770677
     PMS Library
     https://bitbucket.org/xoseperez/justwifi.git#1.1.4