The BH1750 ambient light intensity sensor breakout board has a 16-bit A2D converter built-in that can directly output a digital signal. The output from the sensor is in Lux (Lx) and does not require advanced calculations in the sketch. The BH1750 communicates using I2C Protocol
Wiring Things Up
Start by connecting the radio module.
| Sensor | Arduino | Comment |
|---|---|---|
| GND | GND | Black |
| VCC | VCC (3.3-5V) | Red |
| ADDR | GND | Black |
| SCL | Analog input 5 (A5) | Blue |
| SDA | Analog input 4 (A4) | Green |
Example
This example uses the external BH1750 library found here. Please install it and restart the Arduino IDE before trying to compile.
/**
* The MySensors Arduino library handles the wireless radio link and protocol
* between your home built sensors/actuators and HA controller of choice.
* The sensors forms a self healing radio network with optional repeaters. Each
* repeater and gateway builds a routing tables in EEPROM which keeps track of the
* network topology allowing messages to be routed to nodes.
*
* Created by Henrik Ekblad <[email protected]>
* Copyright (C) 2013-2015 Sensnology AB
* Full contributor list: https://github.com/mysensors/Arduino/graphs/contributors
*
* Documentation: http://www.mysensors.org
* Support Forum: http://forum.mysensors.org
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* version 2 as published by the Free Software Foundation.
*
*******************************
*
* REVISION HISTORY
* Version 1.0 - idefix
*
* DESCRIPTION
* Arduino BH1750FVI Light sensor
* communicate using I2C Protocol
* this library enable 2 slave device addresses
* Main address 0x23
* secondary address 0x5C
* connect the sensor as follows :
*
* VCC >>> 5V
* Gnd >>> Gnd
* ADDR >>> NC or GND
* SCL >>> A5
* SDA >>> A4
* https://www.mysensors.org/build/light-bh1750
*/
// Enable debug prints to serial monitor
#define MY_DEBUG
// Enable and select radio type attached
#define MY_RADIO_RF24
//#define MY_RADIO_RFM69
#include <MySensors.h>
#include <BH1750.h>
#include <Wire.h>
#define CHILD_ID_LIGHT 0
unsigned long SLEEP_TIME = 30000; // Sleep time between reads (in milliseconds)
BH1750 lightSensor;
// V_LIGHT_LEVEL should only be used for uncalibrated light level 0-100%.
// If your controller supports the new V_LEVEL variable, use this instead for
// transmitting LUX light level.
MyMessage msg(CHILD_ID_LIGHT, V_LIGHT_LEVEL);
// MyMessage msg(CHILD_ID_LIGHT, V_LEVEL);
uint16_t lastlux;
void setup()
{
lightSensor.begin();
}
void presentation() {
// Send the sketch version information to the gateway and Controller
sendSketchInfo("Light Lux Sensor", "1.0");
// Register all sensors to gateway (they will be created as child devices)
present(CHILD_ID_LIGHT, S_LIGHT_LEVEL);
}
void loop()
{
uint16_t lux = lightSensor.readLightLevel();// Get Lux value
Serial.println(lux);
if (lux != lastlux) {
send(msg.set(lux));
lastlux = lux;
}
sleep(SLEEP_TIME);
}
