Fork of the espurna firmware for `mhsw` switches
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// -----------------------------------------------------------------------------
// BH1750 Liminosity sensor over I2C
// Copyright (C) 2017-2018 by Xose Pérez <xose dot perez at gmail dot com>
// -----------------------------------------------------------------------------
#if SENSOR_SUPPORT && BH1750_SUPPORT
#pragma once
#include "Arduino.h"
#include "I2CSensor.h"
#if I2C_USE_BRZO
#include <brzo_i2c.h>
#else
#include <Wire.h>
#endif
#define BH1750_CONTINUOUS_HIGH_RES_MODE 0x10 // Start measurement at 1lx resolution. Measurement time is approx 120ms.
#define BH1750_CONTINUOUS_HIGH_RES_MODE_2 0x11 // Start measurement at 0.5lx resolution. Measurement time is approx 120ms.
#define BH1750_CONTINUOUS_LOW_RES_MODE 0x13 // Start measurement at 4lx resolution. Measurement time is approx 16ms.
#define BH1750_ONE_TIME_HIGH_RES_MODE 0x20 // Start measurement at 1lx resolution. Measurement time is approx 120ms.
// Device is automatically set to Power Down after measurement.
#define BH1750_ONE_TIME_HIGH_RES_MODE_2 0x21 // Start measurement at 0.5lx resolution. Measurement time is approx 120ms.
// Device is automatically set to Power Down after measurement.
#define BH1750_ONE_TIME_LOW_RES_MODE 0x23 // Start measurement at 1lx resolution. Measurement time is approx 120ms.
// Device is automatically set to Power Down after measurement.
class BH1750Sensor : public I2CSensor {
public:
// ---------------------------------------------------------------------
// Public
// ---------------------------------------------------------------------
BH1750Sensor(): I2CSensor() {
_sensor_id = SENSOR_BH1750_ID;
_count = 1;
}
// ---------------------------------------------------------------------
void setMode(unsigned char mode) {
if (_mode == mode) return;
_mode = mode;
_dirty = true;
}
// ---------------------------------------------------------------------
unsigned char getMode() {
return _mode;
}
// ---------------------------------------------------------------------
// Sensor API
// ---------------------------------------------------------------------
// Initialization method, must be idempotent
void begin() {
if (!_dirty) return;
_dirty = false;
// I2C auto-discover
unsigned char addresses[] = {0x23, 0x5C};
_address = _begin_i2c(_address, sizeof(addresses), addresses);
if (_address == 0) return;
// Run configuration on next update
_run_configure = true;
}
// Descriptive name of the sensor
String description() {
char buffer[25];
snprintf(buffer, sizeof(buffer), "BH1750 @ I2C (0x%02X)", _address);
return String(buffer);
}
// Type for slot # index
unsigned char type(unsigned char index) {
_error = SENSOR_ERROR_OK;
if (index == 0) return MAGNITUDE_LUX;
_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;
_lux = _read();
}
// Current value for slot # index
double value(unsigned char index) {
_error = SENSOR_ERROR_OK;
if (index == 0) return _lux;
_error = SENSOR_ERROR_OUT_OF_RANGE;
return 0;
}
protected:
void _configure() {
#if I2C_USE_BRZO
uint8_t buffer[1] = {_mode};
brzo_i2c_start_transaction(_address, I2C_SCL_FREQUENCY);
brzo_i2c_write(buffer, 1, false);
brzo_i2c_end_transaction();
#else
Wire.beginTransmission(_address);
Wire.write(_mode);
Wire.endTransmission();
#endif
}
double _read() {
double level;
uint8_t buffer[2];
// For one-shot modes reconfigure sensor & wait for conversion
if (_run_configure) {
_configure();
// According to datasheet
// conversion time is ~16ms for low resolution
// and ~120 for high resolution
// but more time is needed
unsigned long wait = (_mode & 0x02) ? 24 : 180;
unsigned long start = millis();
while (millis() - start < wait) delay(1);
// Keep on running configure each time if one-shot mode
_run_configure = _mode & 0x20;
}
#if I2C_USE_BRZO
brzo_i2c_start_transaction(_address, I2C_SCL_FREQUENCY);
brzo_i2c_read(buffer, 2, false);
brzo_i2c_end_transaction();
#else
Wire.beginTransmission(_address);
Wire.requestFrom(_address, (unsigned char) 2);
buffer[0] = Wire.read();
buffer[1] = Wire.read();
Wire.endTransmission();
#endif
// Check data
if (buffer[0] == 0xFF) {
_error = SENSOR_ERROR_CRC;
_run_configure = true;
return 0;
}
level = buffer[0] * 256 + buffer[1];
return level / 1.2;
}
unsigned char _mode;
bool _run_configure = false;
double _lux = 0;
};
#endif // SENSOR_SUPPORT && BH1750_SUPPORT