NOTE.The item is for robot kit, raindrops, rain sensor, monitoring can be used for a variety of weather conditions, and converted into the number of the reference signal and the AO output. The sensor uses the FR-04 high-quality double-sided materials, King Size 5.0 * 4.0CM, and with the surface of the nickel plating treatment, against oxidative, conductivity, superior performance and longevity; The output in the form: digital switching outputs (0 and 1) and analog AO voltage output; TTL-level output, TTL output valid signal is low. Driving capability 100MA so, can directly drive relays, buzzer, a small fan, and so on. Sensitivity can be adjusted via potentiometer LED lights up when there is no rain output is high, raindrop up, the output ground level, LED light.