Description
The ALS-PT19 analog light sensor is a great way to upgrade a project that uses a photocell and needs RoHS compliance. Unlike the standard CDS photocells, these do carry a ROHS certification. We find these sensors also do a better job measuring the light level in the human vision range due to the high rejection ratio of infrared radiation found with this sensor.
It’s a pretty simple sensor; just give it 2.5V-5.5V or so to power it. Now measure the analog voltage on the OUT pin. That’s it! The voltage will increase when the sensor detects more light.

