This is Robotics 801S Vibration / Shock Sensor.
Vibrations can be an indicator that trouble is coming. It can be your machine going haywire, a gear on a robot missing teeth, or worse, a looming earthquake! In this vibration sensor tutorial, we will look at how to detect vibrations using specially designed sensors and an Arduino microcontroller.
The 801S shock and vibration sensor, by itself, changes its resistance when subjected to vibrations. The resistance changes are so extreme that the 801S is like a switch. The datasheet claims that this gold plated device can withstand 60 million shocks. As with most resistance-varying devices, the 801S is connected in a voltage divider circuit to get a voltage output.
It’s a high sensitivity 801S Vibration Sensor module, which has two output signal pin. one digital pin(D0), When it detects some vibration up to a certain threshold, it can output High or Low level. One analog pin(A0), it can real-time output voltage signal of the 801S vibration.
A0: Analog signal output pin
D0: Digital signal output pin