Fork of the espurna firmware for `mhsw` switches
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// -----------------------------------------------------------------------------
// 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"
#if I2C_USE_BRZO
#include <brzo_i2c.h>
#else
#include <Wire.h>
#endif
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;
_dirty = false;
// I2C auto-discover
unsigned char addresses[] = {0x45};
_address = _begin_i2c(_address, sizeof(addresses), addresses);
if (_address == 0) return;
}
// 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 < _count) {
_error = SENSOR_ERROR_OK;
if (index == 0) return MAGNITUDE_TEMPERATURE;
if (index == 1) return MAGNITUDE_HUMIDITY;
}
_error = SENSOR_ERROR_OUT_OF_RANGE;
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];
#if I2C_USE_BRZO
buffer[0] = 0x2C;
buffer[1] = 0x06;
brzo_i2c_start_transaction(_address, I2C_SCL_FREQUENCY);
brzo_i2c_write(buffer, 2, false);
#else
Wire.beginTransmission(_address);
Wire.write(0x2C);
Wire.write(0x06);
if (Wire.endTransmission() != 0) {
_error = SENSOR_ERROR_TIMEOUT;
return;
}
#endif
delay(500);
#if I2C_USE_BRZO
brzo_i2c_read(buffer, 6, false);
brzo_i2c_end_transaction();
#else
Wire.requestFrom(_address, (unsigned char) 6);
for (int i=0; i<6; i++) buffer[i] = Wire.read();
delay(50);
if (Wire.available() != 0) {
_error = SENSOR_ERROR_CRC;
return;
}
#endif
// 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) {
_error = SENSOR_ERROR_OK;
if (index == 0) return _temperature;
if (index == 1) return _humidity;
_error = SENSOR_ERROR_OUT_OF_RANGE;
return 0;
}
protected:
double _temperature = 0;
unsigned char _humidity = 0;
};
#endif // SENSOR_SUPPORT && SHT3X_I2C_SUPPORT