The AS3935 from ams is a programmable lightning sensor IC that detects the presence and approach of potentially hazardous lightning activity in the vicinity. It detects intra-cloud activity, as well as cloud to ground flashes, often enabling risk to be evaluated for approaching storms.

The AS3935 detects lightning activity as it approaches from up to 40 km away. In addition, the AS3935 identifies and rejects interference signals from common man-made sources, including fluorescent lighting, motors, microwave ovens, and switches.

Based on scientific research, the distance of the storm activity can be statistically calculated from the measured signals. This information allows the user to set warning levels appropriate for their specific application. Personal safety can be set at the most conservative alert, whereas equipment protection can balance confidence, signal strength, and battery life.

The flexible IC allows for configurability that allows the part to work both indoors as well as outdoors, just by changing the gain setting in a register.