BH1750 light intensity sensor
This sensor uses the I2C interface standard to provide light intensity values in lux.
Figure 1: BH1750 ambient light sensor module
Hardware interface
The sensor requires an input voltage of 3.3V and so it works well with the Photon2. Figure 2 shows a sample breadboard layout.
Figure 2: BH1750 connections
The module has five pins, two for power and ground, two for the I2C connection,
and a fifth pin labelled ADDR. This pin is used to switch between two I2C
addresses when you are using more than one module. As long as you are only using a single
module, the ADDR pin can be ignored.
| Pin label | Explanation |
|---|---|
| VCC | Power input |
| GND | Ground |
| SCL | I2C clock |
| SDA | I2C data |
The SCL and SDA pins are simply connected to the SCL and SDA pins on the Photon2.
NB: Check the pin labels on your actual device. They may come in a different order to the ones shown in Figure 2.
Software
The BH1750 library can be found in the Particle web IDE. It comes with an example sketch that works with no modifications.
BH1750 ambient light sensor