Example Code for Arduino-Light Intensity Measurement

Hardware Preparation

• BH1750 Light Sensor (SKU: 975), Quantity: 1, Purchase Link: https://www.dfrobot.com/product-975.html
• Arduino Board, Quantity: 1
• Connecting Wires, Quantity: Several

Software Preparation

• Development Tool: Arduino IDE (Download link: https://www.arduino.cc/en/software)
• Required Libraries: Wire.h (built-in), math.h (built-in)

Wiring Diagram

Sample Code

/*
 Sample code for the BH1750 Light sensor
 Version 0.2
 website:www.DFRobot.com
 Connection:
 VCC-5v
 GND-GND
 SCL-SCL(analog pin 5)
 SDA-SDA(analog pin 4)
 ADD-NC
 */
#include <Wire.h> //BH1750 I2C Mode
#include <math.h>
int BH1750address = 0x23; //setting I2C address
byte buff[2];
void setup() {
        Wire.begin();
        Serial.begin(9600);//init Serail band rate
}
void loop() {
        int i;
        uint16_t val=0;
        BH1750_Init(BH1750address);
        delay(200);
        if(2==BH1750_Read(BH1750address)) {
                val=((buff[0]<<8)|buff[1])/1.2;
                Serial.print(val,DEC);
                Serial.println("[lx]");
        }
        delay(150);
}
int BH1750_Read(int address) {
        int i=0;
        Wire.beginTransmission(address);
        Wire.requestFrom(address, 2);
        while(Wire.available()) {
                buff[i] = Wire.read();  // receive one byte
                i++;
        }
        Wire.endTransmission();
        return i;
}
void BH1750_Init(int address) {
        Wire.beginTransmission(address);
        Wire.write(0x10);//1lx reolution 120ms
        Wire.endTransmission();
}