92 lines
2.4 KiB
C++
Executable file
92 lines
2.4 KiB
C++
Executable file
/*
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This is a library for the BH1750FVI Digital Light Sensor
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breakout board.
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The board uses I2C for communication. 2 pins are required to
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interface to the device.
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based on Christopher Laws, March, 2013 code.
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*/
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#include "SensorBH1750.h"
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#include <util/delay.h>
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#define BH1750_I2CADDR 0x23
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// No active state
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#define BH1750_POWER_DOWN 0x00
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// Waiting for measurement command
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#define BH1750_POWER_ON 0x01
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// Reset data register value - not accepted in POWER_DOWN mode
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#define BH1750_RESET 0x07
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// Start measurement at 1lx resolution. Measurement time is approx 120ms.
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#define BH1750_CONTINUOUS_HIGH_RES_MODE 0x10
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// Start measurement at 0.5lx resolution. Measurement time is approx 120ms.
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#define BH1750_CONTINUOUS_HIGH_RES_MODE_2 0x11
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// Start measurement at 4lx resolution. Measurement time is approx 16ms.
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#define BH1750_CONTINUOUS_LOW_RES_MODE 0x13
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// Start measurement at 1lx resolution. Measurement time is approx 120ms.
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// Device is automatically set to Power Down after measurement.
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#define BH1750_ONE_TIME_HIGH_RES_MODE 0x20
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// Start measurement at 0.5lx resolution. Measurement time is approx 120ms.
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// Device is automatically set to Power Down after measurement.
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#define BH1750_ONE_TIME_HIGH_RES_MODE_2 0x21
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// Start measurement at 1lx resolution. Measurement time is approx 120ms.
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// Device is automatically set to Power Down after measurement.
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#define BH1750_ONE_TIME_LOW_RES_MODE 0x23
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void SensorBH1750::setup() {
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Wire.begin();
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configure(BH1750_ONE_TIME_HIGH_RES_MODE);
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}
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void SensorBH1750::configure(uint8_t mode) {
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switch (mode) {
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case BH1750_CONTINUOUS_HIGH_RES_MODE:
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case BH1750_CONTINUOUS_HIGH_RES_MODE_2:
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case BH1750_CONTINUOUS_LOW_RES_MODE:
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case BH1750_ONE_TIME_HIGH_RES_MODE:
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case BH1750_ONE_TIME_HIGH_RES_MODE_2:
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case BH1750_ONE_TIME_LOW_RES_MODE:
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// apply a valid mode change
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Wire.beginTransmission(BH1750_I2CADDR);
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Wire.write(mode);
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Wire.endTransmission();
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_delay_ms(10);
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break;
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default:
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// Invalid measurement mode
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DEBUG("Invalid measurement mode");
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break;
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}
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}
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void SensorBH1750::read(LightData& data) {
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uint16_t level;
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Wire.beginTransmission(BH1750_I2CADDR);
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Wire.requestFrom(BH1750_I2CADDR, 2);
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level = Wire.read();
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level <<= 8;
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level |= Wire.read();
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Wire.endTransmission();
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data.lumen = level/1.2; // convert to lux
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}
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