You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
172 lines
5.8 KiB
172 lines
5.8 KiB
// -----------------------------------------------------------------------------
|
|
// 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
|