espurna-sonoff-pow/espurna/sensors/SHT3XI2CSensor.h

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2018-06-06 15:28:17 +02:00
// -----------------------------------------------------------------------------
// SHT3X Sensor over I2C (Wemos)
// Copyright (C) 2017-2018 by Xose Pérez <xose dot perez at gmail dot com>
// -----------------------------------------------------------------------------
#if SENSOR_SUPPORT && SHT3X_I2C_SUPPORT
#pragma once
#include "Arduino.h"
#include "I2CSensor.h"
class SHT3XI2CSensor : public I2CSensor {
public:
// ---------------------------------------------------------------------
// Public
// ---------------------------------------------------------------------
SHT3XI2CSensor(): I2CSensor() {
_sensor_id = SENSOR_SHT3X_I2C_ID;
_count = 2;
}
// ---------------------------------------------------------------------
// Sensor API
// ---------------------------------------------------------------------
// Initialization method, must be idempotent
void begin() {
if (!_dirty) return;
// I2C auto-discover
unsigned char addresses[] = {0x45};
_address = _begin_i2c(_address, sizeof(addresses), addresses);
if (_address == 0) return;
_ready = true;
_dirty = false;
}
// Descriptive name of the sensor
String description() {
char buffer[25];
snprintf(buffer, sizeof(buffer), "SHT3X @ I2C (0x%02X)", _address);
return String(buffer);
}
// Type for slot # index
unsigned char type(unsigned char index) {
if (index == 0) return MAGNITUDE_TEMPERATURE;
if (index == 1) return MAGNITUDE_HUMIDITY;
return MAGNITUDE_NONE;
}
// Pre-read hook (usually to populate registers with up-to-date data)
void pre() {
_error = SENSOR_ERROR_OK;
unsigned char buffer[6];
i2c_write_uint8(_address, 0x2C, 0x06);
nice_delay(500);
i2c_read_buffer(_address, buffer, 6);
// cTemp msb, cTemp lsb, cTemp crc, humidity msb, humidity lsb, humidity crc
_temperature = ((((buffer[0] * 256.0) + buffer[1]) * 175) / 65535.0) - 45;
_humidity = ((((buffer[3] * 256.0) + buffer[4]) * 100) / 65535.0);
}
// Current value for slot # index
double value(unsigned char index) {
if (index == 0) return _temperature;
if (index == 1) return _humidity;
return 0;
}
protected:
double _temperature = 0;
unsigned char _humidity = 0;
};
#endif // SENSOR_SUPPORT && SHT3X_I2C_SUPPORT