Fork of the espurna firmware for `mhsw` switches
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// -----------------------------------------------------------------------------
// HDC1080 / 831R Sensor over I2C
// Based on SI7021 / HTU21D Sensor over I2C
// Copyright (C) 2017-2019 by Xose Pérez <xose dot perez at gmail dot com>
// Copyright (C) 2020 by Alexander Kolesnikov <vtochq at gmail dot com>
// -----------------------------------------------------------------------------
#if SENSOR_SUPPORT && HDC1080_SUPPORT
#pragma once
#include "I2CSensor.h"
#include "../utils.h"
#define HDC1080_SCL_FREQUENCY 200
// ref. http://www.ti.com/lit/ds/symlink/hdc1080.pdf
// Device ID. Should be the same for every device.
#define HDC1080_DEVICE_ID 0x1050
#define HDC1080_CMD_TMP 0x00
#define HDC1080_CMD_HUM 0x01
class HDC1080Sensor : public I2CSensor<> {
public:
// ---------------------------------------------------------------------
// Public
// ---------------------------------------------------------------------
HDC1080Sensor() {
_sensor_id = SENSOR_HDC1080_ID;
}
// ---------------------------------------------------------------------
// Sensor API
// ---------------------------------------------------------------------
// Initialization method, must be idempotent
void begin() {
if (!_dirty) return;
_init();
_dirty = !_ready;
}
// Descriptive name of the sensor
String description() {
char buffer[25];
snprintf_P(buffer, sizeof(buffer), PSTR("HDC1080 @ I2C (0x%02X)"), _address);
return String(buffer);
}
// Descriptive name of the slot # index
String description(unsigned char index) {
return description();
};
// 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;
double value;
value = _read(HDC1080_CMD_TMP);
if (_error != SENSOR_ERROR_OK) return;
_temperature = (165 * value / 65536) - 40;
value = _read(HDC1080_CMD_HUM);
if (_error != SENSOR_ERROR_OK) return;
value = (value / 65536)*100;
_humidity = constrain(value, 0, 100);
}
// Current value for slot # index
double value(unsigned char index) {
if (index == 0) return _temperature;
if (index == 1) return _humidity;
return 0;
}
protected:
// ---------------------------------------------------------------------
// Protected
// ---------------------------------------------------------------------
void _init() {
// I2C auto-discover
unsigned char addresses[] = {0x40};
_address = _begin_i2c(_address, sizeof(addresses), addresses);
if (_address == 0) return;
// Check device ID before doing anything else
// ref. https://github.com/xoseperez/espurna/issues/2270#issuecomment-639239944
// > Also there are clones of HDC1080 and they may have different Device ID
// > values. You need to check it by reading and debug output this bytes.
i2c_write_uint8(_address, 0xFF);
_device_id = i2c_read_uint16(_address);
if (_device_id == HDC1080_DEVICE_ID) {
_ready = true;
_count = 2;
return;
}
DEBUG_MSG_P(PSTR("[HDC1080] ERROR: Expected Device ID %04X, received %04X\n"), HDC1080_DEVICE_ID, _device_id);
_count = 0;
i2cReleaseLock(_address);
_previous_address = 0;
_error = SENSOR_ERROR_UNKNOWN_ID;
// Setting _address to 0 forces auto-discover
// This might be necessary at this stage if there is a
// different sensor in the hardcoded address
_address = 0;
_ready = false;
}
unsigned int _read(uint8_t command) {
// Request measurement
i2c_write_uint8(_address, command);
// When not using clock stretching (*_NOHOLD commands) delay here
// is needed to wait for the measurement.
// According to datasheet the max. conversion time is ~22ms
nice_delay(50);
// Clear the last to bits of LSB to 00.
// According to datasheet LSB of Temp and RH is always xxxxxx00
unsigned int value = i2c_read_uint16(_address) & 0xFFFC;
// We should be checking there are no pending bytes in the buffer
// and raise a CRC error if there are
_error = SENSOR_ERROR_OK;
return value;
}
uint16_t _device_id = 0;
double _temperature = 0;
double _humidity = 0;
};
#endif // SENSOR_SUPPORT && HDC1080_SUPPORT