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- // -----------------------------------------------------------------------------
- // BME280/BMP280 Sensor over I2C
- // Copyright (C) 2017-2018 by Xose Pérez <xose dot perez at gmail dot com>
- // -----------------------------------------------------------------------------
-
- #if SENSOR_SUPPORT && BMX280_SUPPORT
-
- #pragma once
-
- #include "Arduino.h"
- #include "I2CSensor.h"
-
- #define BMX280_CHIP_BMP280 0x58
- #define BMX280_CHIP_BME280 0x60
-
- #define BMX280_REGISTER_DIG_T1 0x88
- #define BMX280_REGISTER_DIG_T2 0x8A
- #define BMX280_REGISTER_DIG_T3 0x8C
-
- #define BMX280_REGISTER_DIG_P1 0x8E
- #define BMX280_REGISTER_DIG_P2 0x90
- #define BMX280_REGISTER_DIG_P3 0x92
- #define BMX280_REGISTER_DIG_P4 0x94
- #define BMX280_REGISTER_DIG_P5 0x96
- #define BMX280_REGISTER_DIG_P6 0x98
- #define BMX280_REGISTER_DIG_P7 0x9A
- #define BMX280_REGISTER_DIG_P8 0x9C
- #define BMX280_REGISTER_DIG_P9 0x9E
-
- #define BMX280_REGISTER_DIG_H1 0xA1
- #define BMX280_REGISTER_DIG_H2 0xE1
- #define BMX280_REGISTER_DIG_H3 0xE3
- #define BMX280_REGISTER_DIG_H4 0xE4
- #define BMX280_REGISTER_DIG_H5 0xE5
- #define BMX280_REGISTER_DIG_H6 0xE7
-
- #define BMX280_REGISTER_CHIPID 0xD0
- #define BMX280_REGISTER_VERSION 0xD1
- #define BMX280_REGISTER_SOFTRESET 0xE0
-
- #define BMX280_REGISTER_CAL26 0xE1
-
- #define BMX280_REGISTER_CONTROLHUMID 0xF2
- #define BMX280_REGISTER_CONTROL 0xF4
- #define BMX280_REGISTER_CONFIG 0xF5
- #define BMX280_REGISTER_PRESSUREDATA 0xF7
- #define BMX280_REGISTER_TEMPDATA 0xFA
- #define BMX280_REGISTER_HUMIDDATA 0xFD
-
- class BMX280Sensor : public I2CSensor {
-
- public:
-
- static unsigned char addresses[2];
-
- // ---------------------------------------------------------------------
- // Public
- // ---------------------------------------------------------------------
-
- BMX280Sensor(): I2CSensor() {
- _sensor_id = SENSOR_BMX280_ID;
- }
-
- // ---------------------------------------------------------------------
- // Sensor API
- // ---------------------------------------------------------------------
-
- // Initialization method, must be idempotent
- void begin() {
-
- if (!_dirty) return;
- _dirty = false;
- _chip = 0;
-
- // I2C auto-discover
- _address = _begin_i2c(_address, sizeof(BMX280Sensor::addresses), BMX280Sensor::addresses);
- if (_address == 0) return;
-
- // Init
- _init();
-
- }
-
- // Descriptive name of the sensor
- String description() {
- char buffer[20];
- snprintf(buffer, sizeof(buffer), "%s @ I2C (0x%02X)", _chip == BMX280_CHIP_BME280 ? "BME280" : "BMP280", _address);
- return String(buffer);
- }
-
- // Type for slot # index
- unsigned char 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
- _forceRead();
- #endif
- _read();
-
- }
-
- // 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 _temperature;
- #endif
- #if BMX280_PRESSURE > 0
- if (index == i++) return _pressure / 100;
- #endif
- #if BMX280_HUMIDITY > 0
- if (_chip == BMX280_CHIP_BME280) {
- if (index == i) return _humidity;
- }
- #endif
- }
- _error = SENSOR_ERROR_OUT_OF_RANGE;
- return 0;
-
- }
-
- // Load the configuration manifest
- static void manifest(JsonArray& sensors) {
-
- char buffer[10];
-
- JsonObject& sensor = sensors.createNestedObject();
- sensor["sensor_id"] = SENSOR_BMX280_ID;
- JsonArray& fields = sensor.createNestedArray("fields");
-
- {
- JsonObject& field = fields.createNestedObject();
- field["tag"] = UI_TAG_SELECT;
- field["name"] = "address";
- field["label"] = "Address";
- JsonArray& options = field.createNestedArray("options");
- {
- JsonObject& option = options.createNestedObject();
- option["name"] = "auto";
- option["value"] = 0;
- }
- for (unsigned char i=0; i< sizeof(BMX280Sensor::addresses); i++) {
- JsonObject& option = options.createNestedObject();
- snprintf(buffer, sizeof(buffer), "0x%02X", BMX280Sensor::addresses[i]);
- option["name"] = String(buffer);
- option["value"] = BMX280Sensor::addresses[i];
- }
- }
-
- };
-
- void getConfig(JsonObject& root) {
- root["sensor_id"] = _sensor_id;
- root["address"] = _address;
- };
-
- void setConfig(JsonObject& root) {
- if (root.containsKey("address")) setAddress(root["address"]);
- };
-
- protected:
-
- void _init() {
-
- // Make sure sensor had enough time to turn on. BMX280 requires 2ms to start up
- delay(10);
-
- // Check sensor correctly initialized
- _chip = i2c_read_uint8(_address, BMX280_REGISTER_CHIPID);
- if ((_chip != BMX280_CHIP_BME280) && (_chip != BMX280_CHIP_BMP280)) {
- _chip = 0;
- i2cReleaseLock(_address);
- _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
-
- _readCoefficients();
-
- unsigned char data = 0;
- i2c_write_uint8(_address, BMX280_REGISTER_CONTROL, data);
-
- data = (BMX280_STANDBY << 0x5) & 0xE0;
- data |= (BMX280_FILTER << 0x02) & 0x1C;
- i2c_write_uint8(_address, BMX280_REGISTER_CONFIG, data);
-
- data = (BMX280_HUMIDITY) & 0x07;
- i2c_write_uint8(_address, BMX280_REGISTER_CONTROLHUMID, data);
-
- data = (BMX280_TEMPERATURE << 5) & 0xE0;
- data |= (BMX280_PRESSURE << 2) & 0x1C;
- data |= (BMX280_MODE) & 0x03;
- i2c_write_uint8(_address, BMX280_REGISTER_CONTROL, data);
-
- _measurement_delay = _measurementTime();
-
- }
-
- void _readCoefficients() {
- _bmx280_calib.dig_T1 = i2c_read_uint16_le(_address, BMX280_REGISTER_DIG_T1);
- _bmx280_calib.dig_T2 = i2c_read_int16_le(_address, BMX280_REGISTER_DIG_T2);
- _bmx280_calib.dig_T3 = i2c_read_int16_le(_address, BMX280_REGISTER_DIG_T3);
-
- _bmx280_calib.dig_P1 = i2c_read_uint16_le(_address, BMX280_REGISTER_DIG_P1);
- _bmx280_calib.dig_P2 = i2c_read_int16_le(_address, BMX280_REGISTER_DIG_P2);
- _bmx280_calib.dig_P3 = i2c_read_int16_le(_address, BMX280_REGISTER_DIG_P3);
- _bmx280_calib.dig_P4 = i2c_read_int16_le(_address, BMX280_REGISTER_DIG_P4);
- _bmx280_calib.dig_P5 = i2c_read_int16_le(_address, BMX280_REGISTER_DIG_P5);
- _bmx280_calib.dig_P6 = i2c_read_int16_le(_address, BMX280_REGISTER_DIG_P6);
- _bmx280_calib.dig_P7 = i2c_read_int16_le(_address, BMX280_REGISTER_DIG_P7);
- _bmx280_calib.dig_P8 = i2c_read_int16_le(_address, BMX280_REGISTER_DIG_P8);
- _bmx280_calib.dig_P9 = i2c_read_int16_le(_address, BMX280_REGISTER_DIG_P9);
-
- _bmx280_calib.dig_H1 = i2c_read_uint8(_address, BMX280_REGISTER_DIG_H1);
- _bmx280_calib.dig_H2 = i2c_read_int16_le(_address, BMX280_REGISTER_DIG_H2);
- _bmx280_calib.dig_H3 = i2c_read_uint8(_address, BMX280_REGISTER_DIG_H3);
- _bmx280_calib.dig_H4 = (i2c_read_uint8(_address, BMX280_REGISTER_DIG_H4) << 4) | (i2c_read_uint8(_address, BMX280_REGISTER_DIG_H4+1) & 0xF);
- _bmx280_calib.dig_H5 = (i2c_read_uint8(_address, BMX280_REGISTER_DIG_H5+1) << 4) | (i2c_read_uint8(_address, BMX280_REGISTER_DIG_H5) >> 4);
- _bmx280_calib.dig_H6 = (int8_t) i2c_read_uint8(_address, BMX280_REGISTER_DIG_H6);
- }
-
- unsigned long _measurementTime() {
-
- // 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 _forceRead() {
-
- // 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 = i2c_read_uint8(_address, BMX280_REGISTER_CONTROL);
- value = (value & 0xFC) + 0x01;
- i2c_write_uint8(_address, BMX280_REGISTER_CONTROL, value);
-
- delay(_measurement_delay);
-
- }
-
- void _read() {
-
- #if BMX280_TEMPERATURE > 0
- int32_t adc_T = i2c_read_uint16(_address, BMX280_REGISTER_TEMPDATA);
- adc_T <<= 8;
- adc_T |= i2c_read_uint8(_address, BMX280_REGISTER_TEMPDATA+2);
- adc_T >>= 4;
-
- int32_t var1t = ((((adc_T>>3) -
- ((int32_t)_bmx280_calib.dig_T1 <<1))) *
- ((int32_t)_bmx280_calib.dig_T2)) >> 11;
-
- int32_t var2t = (((((adc_T>>4) -
- ((int32_t)_bmx280_calib.dig_T1)) *
- ((adc_T>>4) - ((int32_t)_bmx280_calib.dig_T1))) >> 12) *
- ((int32_t)_bmx280_calib.dig_T3)) >> 14;
-
- int32_t t_fine = var1t + var2t;
-
- double T = (t_fine * 5 + 128) >> 8;
- _temperature = T / 100;
- #else
- int32_t t_fine = 102374; // ~20ºC
- #endif
-
- // -----------------------------------------------------------------
-
- #if BMX280_PRESSURE > 0
- int64_t var1, var2, p;
-
- int32_t adc_P = i2c_read_uint16(_address, BMX280_REGISTER_PRESSUREDATA);
- adc_P <<= 8;
- adc_P |= i2c_read_uint8(_address, BMX280_REGISTER_PRESSUREDATA+2);
- adc_P >>= 4;
-
- var1 = ((int64_t)t_fine) - 128000;
- var2 = var1 * var1 * (int64_t)_bmx280_calib.dig_P6;
- var2 = var2 + ((var1*(int64_t)_bmx280_calib.dig_P5)<<17);
- var2 = var2 + (((int64_t)_bmx280_calib.dig_P4)<<35);
- var1 = ((var1 * var1 * (int64_t)_bmx280_calib.dig_P3)>>8) +
- ((var1 * (int64_t)_bmx280_calib.dig_P2)<<12);
- var1 = (((((int64_t)1)<<47)+var1))*((int64_t)_bmx280_calib.dig_P1)>>33;
- if (var1 == 0) return; // avoid exception caused by division by zero
-
- p = 1048576 - adc_P;
- p = (((p<<31) - var2)*3125) / var1;
- var1 = (((int64_t)_bmx280_calib.dig_P9) * (p>>13) * (p>>13)) >> 25;
- var2 = (((int64_t)_bmx280_calib.dig_P8) * p) >> 19;
-
- p = ((p + var1 + var2) >> 8) + (((int64_t)_bmx280_calib.dig_P7)<<4);
- _pressure = (double) p / 256;
- #endif
-
- // -----------------------------------------------------------------
-
- #if BMX280_HUMIDITY > 0
- if (_chip == BMX280_CHIP_BME280) {
-
- int32_t adc_H = i2c_read_uint16(_address, BMX280_REGISTER_HUMIDDATA);
-
- int32_t v_x1_u32r;
-
- v_x1_u32r = (t_fine - ((int32_t)76800));
-
- v_x1_u32r = (((((adc_H << 14) - (((int32_t)_bmx280_calib.dig_H4) << 20) -
- (((int32_t)_bmx280_calib.dig_H5) * v_x1_u32r)) + ((int32_t)16384)) >> 15) *
- (((((((v_x1_u32r * ((int32_t)_bmx280_calib.dig_H6)) >> 10) *
- (((v_x1_u32r * ((int32_t)_bmx280_calib.dig_H3)) >> 11) + ((int32_t)32768))) >> 10) +
- ((int32_t)2097152)) * ((int32_t)_bmx280_calib.dig_H2) + 8192) >> 14));
-
- v_x1_u32r = (v_x1_u32r - (((((v_x1_u32r >> 15) * (v_x1_u32r >> 15)) >> 7) *
- ((int32_t)_bmx280_calib.dig_H1)) >> 4));
-
- v_x1_u32r = (v_x1_u32r < 0) ? 0 : v_x1_u32r;
- v_x1_u32r = (v_x1_u32r > 419430400) ? 419430400 : v_x1_u32r;
- double h = (v_x1_u32r >> 12);
- _humidity = h / 1024.0;
-
- }
- #endif
-
- }
-
- // ---------------------------------------------------------------------
-
- unsigned char _chip;
- unsigned long _measurement_delay;
- double _temperature = 0;
- double _pressure = 0;
- double _humidity = 0;
-
- typedef struct {
-
- uint16_t dig_T1;
- int16_t dig_T2;
- int16_t dig_T3;
-
- uint16_t dig_P1;
- int16_t dig_P2;
- int16_t dig_P3;
- int16_t dig_P4;
- int16_t dig_P5;
- int16_t dig_P6;
- int16_t dig_P7;
- int16_t dig_P8;
- int16_t dig_P9;
-
- uint8_t dig_H1;
- int16_t dig_H2;
- uint8_t dig_H3;
- int16_t dig_H4;
- int16_t dig_H5;
- int8_t dig_H6;
-
- } bmx280_calib_t;
-
- bmx280_calib_t _bmx280_calib;
-
- };
-
- // Static inizializations
-
- unsigned char BMX280Sensor::addresses[2] = {0x76, 0x77};
-
- #endif // SENSOR_SUPPORT && BMX280_SUPPORT
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