Product Overview
Add a crucial layer of environmental awareness to your custom weather station with the SparkFun Lightning Detector. Powered by the AS3935 Franklin Lightning Sensor from AMS OSRAM, this board uses a specialized antenna tuned to the 500kHz band to detect approaching lightning events. Doing so, it can accurately detect cloud-to-ground and intra-cloud strikes at distances of up to 40 kilometers, estimating the distance to the storm front within a 1-kilometer margin across 14 distinct steps.
Advanced Storm Sensing while Filtering the Noise
Detecting lightning electromagnetically often faces the challenge of false positives due to man-made electrical noise. To combat this, the AS3935 features a built-in rejection algorithm that automatically filters out common disturbers.
If your specific environment is exceptionally noisy, our dedicated Arduino library grants you more control over the sensor's behavior:
- Environment Tuning: Toggle between specialized indoor and outdoor sensing profiles to match your deployment location.
- Sensitivity Control: Adjust the noise-floor thresholds to reduce false events in high-RF environments.
- Strike Thresholds: Configure the exact number of lightning strikes required to trigger a hardware interrupt, preventing your microcontroller from being overwhelmed by isolated anomalies.

Interface and Communication
Please be aware that although the AS3935 chip technically supports I2C, SparkFun exclusively supports SPI communication for this board. Due to inconsistent I2C implementation by the manufacturer, we cannot guarantee reliable performance over an I2C bus. That being said, all the hardware is present on the board if you choose to experiment, but our official libraries and technical support are strictly dedicated to the highly dependable SPI connection.
Whether you are monitoring incoming weather for a remote agricultural setup or simply want your home automation system to disconnect sensitive electronics during a storm, this sensor provides the early warning you need!
