116 lines
5.1 KiB
C++
116 lines
5.1 KiB
C++
#ifndef BH1750FVI_h
|
|
#define BH1750FVI_h
|
|
|
|
//#if ARDUINO >= 100
|
|
#include "Arduino.h"
|
|
//#else
|
|
// #include "WProgram.h"
|
|
//#endif
|
|
|
|
#include <Wire.h>
|
|
|
|
//device address options
|
|
#define BH_AddrL 0x23 // Device address when addr pin is LOW
|
|
#define BH_AddrH 0x5C // Device address when addr pin is HIGH
|
|
|
|
//power codes
|
|
#define BH_PowOf 0x00 // power-off code
|
|
#define BH_PowOn 0x01 // power-on code
|
|
#define BH_Reset 0x07 // code to reset the light reading register to zero
|
|
|
|
//mode codes
|
|
#define BH_NoMod 0x02 // No mode specified. Keeps mode the same as before.
|
|
#define BH_EasyH 0x03 // 'easy' mode. basically the same as ContH
|
|
#define BH_ContH 0x10 // continuous full-scale, high-resolution sampling
|
|
#define BH_Conth 0x11 // continuous with twice the resolution but half the max value
|
|
#define BH_ContL 0x13 // continuous full-scale, low-resolution sampling. faster.
|
|
#define BH_SingH 0x20 // take one high-resolution, full-scale sample then turn off
|
|
#define BH_Singh 0x21 // take one high-resolution, half-scale sample then turn off
|
|
#define BH_SingL 0x23 // take one low-resolution, full-scale sample then turn off
|
|
// (happens to be the same as the low address value)
|
|
|
|
//sensitivity codes
|
|
#define BH_MTrHb 0x40 // last 3 bits must be masked to 3 MSB of desired value
|
|
#define BH_MTrLb 0x60 // last 5 bits must be masked to 5 LSB of desired value
|
|
#define BH_MinSv 31 // minimum sensitivity register value, yields Lux * 0.45
|
|
#define BH_MaxSv 254 // maximum sensitivity register value, yields Lux * 3.68
|
|
#define BH_DefSv 69 // default sensitivity register value, yields Lux * 1.00
|
|
|
|
//timing delays. they're actually longer than the datasheet says.
|
|
#define BH_FastD 18 // basic delay in microseconds for a fast sample
|
|
#define BH_SlowD 125 // basic delay in microseconds for a slow sample
|
|
|
|
class BH1750FVI {
|
|
public:
|
|
/*BEGIN
|
|
this is intended to be as error-tolerant as possible. if you don't supply
|
|
a mode, the default mode will be 'easy'. the sensitivity obviously defaults
|
|
to 1.0 (byte value of 69). Default address selection is LOW, which is how
|
|
the BH1750FVI should default if you don't connect anything to its ADDR pin.
|
|
*/void begin(byte mode=BH_EasyH, byte addr=BH_AddrL, double sens=BH_DefSv, int addrPin=-1);
|
|
|
|
/*FRESH SAMPLE POLLING
|
|
Check whether you have already looked at the current sample.
|
|
*/bool sampleIsFresh();
|
|
|
|
/*ACTUALLY GET A READING FROM THE SENSOR
|
|
This is probably all you wanted from this library. Return value is an
|
|
unsigned 16 bit integer with units of Lux. There are three possible modes:
|
|
'r' raw numerical reading, no units, you get what you get
|
|
'c' convert units to Lux or half-Lux, depending on the mode, but don't
|
|
compensate for the sensitivity setting. This allows sensitivity to
|
|
be used as enclosure optics calibration/compensation.
|
|
't' true Lux (or half-Lux) reading, regardless of sensitivity settings.
|
|
*/word getLightLevel(char adjustments='c');
|
|
|
|
word retrieveSample();
|
|
|
|
/*CONTINUOUS SAMPLING
|
|
Return value of this start function is the delay time between refreshes of
|
|
the ambient light reading. After you call this function, you can use getLightLevel()
|
|
to read the most recent ambient light level. If you try to run this ongoing start
|
|
function with a one-time mode argument, it will do nothing and return 0.
|
|
*/word startOngoingSamples(char mode=BH_NoMod);
|
|
|
|
/*ONE-TIME SAMPLE START
|
|
Return value of this start function is the delay time before the new ambient
|
|
light reading will be available. You can check whether the new sample is ready
|
|
yet using sampleIsFresh(). Retrieve that single sample with getLightLevel().
|
|
If you give this one-time start function a continuous mode argument, it will
|
|
do nothing and return 0.
|
|
*/word startSingleSample(char mode=BH_NoMod);
|
|
|
|
/*SENSITIVITY SETTINGS
|
|
This function lets you change the 'sensitivity' of the BH1750FVI by changing
|
|
its sampling time up or down. The sensitivity is stored as a number between
|
|
31 and 254, with a default value of 69. This is intended to compensate for
|
|
having the chip installed in an enclosure that blocks some ambient light.
|
|
The floating point versions of the function allow the sensitivity to be
|
|
given as a ratio between ~0.45 and ~3.68. The return value is the number of
|
|
milliseconds that the chip will take to create a new light level reading.
|
|
*/word setSensitivity(double sens);
|
|
word setSensitivity(float sens);
|
|
word setSensitivity(int sens);
|
|
word setSensitivity(byte sens=BH_DefSv);
|
|
|
|
/*POWERDOWN FUNCTION
|
|
In case you want to turn off the BH1750FVI to save power. Other commands will wake
|
|
the chip back up. Single sample modes automatically turn off the chip after sampling,
|
|
but you can still read the value from it without waking it up.
|
|
*/void powerDown();
|
|
|
|
private:
|
|
void init(byte mode, byte addr, byte sens);
|
|
void i2cWrite(byte dataToSend);
|
|
word i2cRead();
|
|
byte address;
|
|
byte currentMode;
|
|
byte currentSensitivity;
|
|
bool sampleUnseen;
|
|
byte MTreg_hiByte;
|
|
byte MTreg_loByte;
|
|
unsigned long int lastSampleStart;
|
|
word currentSamplingTime;
|
|
};
|
|
#endif
|