Arduino Based Lux Meter Using the BH1750FVI Sensor

This Arduino based lux meter from embedded-lab is unique to the other light intensity meters that we have covered so far. The simplest of lux meters uses a light dependent resistor to detect light intensity (just like this project). This one uses the BH1750FVI Sensor to measure ambient lighting levels - The BH1750FVI chip communcates through I2C (like the RTC here) and produces a 16-Bit value relating to the incident the light intensity in Lux (is the SI unit for illuminance and is equal to one lumen per square meter). This means that you would not need to any calculation/convertion to get the illuminace value. One thing to note about the BH1750FVI sensor is that it is callibrated which means the Lux value that it gives us is very close to the actual illuminance value.

Once the 16 bit Lux values is read from the BH1750FVI, the arduino then uses serial peripheral interface (SPI) communication to print out the result into an 8 digit serial seven segment display that is built around the MAX7219 from Maxim.