Fork of the espurna firmware for `mhsw` switches
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// -----------------------------------------------------------------------------
// BMX280 Sensor
// -----------------------------------------------------------------------------
#pragma once
#include "Arduino.h"
#include "BaseSensor.h"
#include <SparkFunBME280.h>
#define BMX280_CHIP_BMP280 0x58
#define BMX280_CHIP_BME280 0x60
class BMX280Sensor : public BaseSensor {
public:
BMX280Sensor(unsigned char address = BMX280_ADDRESS): BaseSensor() {
// Cache
_address = address;
_measurement_delay = bmeMeasurementTime();
// Init
bme = new BME280();
bme->settings.commInterface = I2C_MODE;
bme->settings.I2CAddress = _address;
bme->settings.runMode = BMX280_MODE;
bme->settings.tStandby = 0;
bme->settings.filter = 0;
bme->settings.tempOverSample = BMX280_TEMPERATURE;
bme->settings.pressOverSample = BMX280_PRESSURE;
bme->settings.humidOverSample = BMX280_HUMIDITY;
// Fix when not measuring temperature, t_fine should have a sensible value
if (BMX280_TEMPERATURE == 0) bme->t_fine = 100000; // aprox 20ºC
// Make sure sensor had enough time to turn on. BMX280 requires 2ms to start up
delay(10);
// Check sensor correctly initialized
_chip = bme->begin();
if ((_chip != BMX280_CHIP_BME280) && (_chip != BMX280_CHIP_BMP280)) {
_chip = 0;
_error = SENSOR_ERROR_UNKNOWN_ID;
}
#if BMX280_TEMPERATURE > 0
++_count;
#endif
#if BMX280_PRESSURE > 0
++_count;
#endif
#if BMX280_HUMIDITY > 0
if (_chip == BMX280_CHIP_BME280) ++_count;
#endif
}
// Descriptive name of the sensor
String name() {
char buffer[20];
snprintf(buffer, sizeof(buffer), "%s @ I2C (0x%02X)", _chip == BMX280_CHIP_BME280 ? "BME280" : "BMP280", _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 BMX280_TEMPERATURE > 0
if (index == i++) return MAGNITUDE_TEMPERATURE;
#endif
#if BMX280_PRESSURE > 0
if (index == i++) return MAGNITUDE_PRESSURE;
#endif
#if BMX280_HUMIDITY > 0
if (_chip == BMX280_CHIP_BME280) {
if (index == i) return MAGNITUDE_HUMIDITY;
}
#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 (_chip == 0) {
_error = SENSOR_ERROR_UNKNOWN_ID;
return;
}
#if BMX280_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 BMX280_TEMPERATURE > 0
if (index == i++) return bme->readTempC();
#endif
#if BMX280_PRESSURE > 0
if (index == i++) return bme->readFloatPressure() / 100;
#endif
#if BMX280_HUMIDITY > 0
if (_chip == BMX280_CHIP_BME280) {
if (index == i) return bme->readFloatHumidity();
}
#endif
}
_error = SENSOR_ERROR_OUT_OF_RANGE;
return 0;
}
protected:
unsigned long bmeMeasurementTime() {
// Measurement Time (as per BMX280 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 BMX280_TEMPERATURE > 0
t += (2.3 * BMX280_TEMPERATURE);
#endif
#if BMX280_PRESSURE > 0
t += (2.3 * BMX280_PRESSURE + 0.575);
#endif
#if BMX280_HUMIDITY > 0
if (_chip == BMX280_CHIP_BME280) {
t += (2.4 * BMX280_HUMIDITY + 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 _chip;
unsigned char _address;
unsigned long _measurement_delay;
};