About this item

The Adafruit ALS‑PT19 Analog Light Sensor Breakout is a compact and accurate module designed to replace traditional photocells. It uses the ALS‑PT19 photodiode, which closely matches the human eye's response and includes built-in infrared filtering for more precise ambient light sensing. The board is extremely small, measuring just 7.8 × 10.6 × 2.4 mm and weighing only 0.2 grams. It operates from a 2.5V to 5.5V power supply and outputs an analog voltage proportional to light intensity. Simple to use, it requires only power, ground, and an analog read pin, making it ideal for DIY electronics, wearables, and prototyping.