This Arduino compatible mercury tilt switch sensor module can detect when it is tilted. It works because the mercury ball flows into the gap between two electrodes and completes the circuit when the module is tilted at an angle.

The sensor opens and closes an electrical circuit through a small amount of liquid mercury. When the module tilts, it outputs low and the corresponding LED lights up.

Test Code

int Led = 13; // define LED Interface
int buttonpin = 3; // define the mercury tilt switch sensor interface
int val; // define numeric variables val

void setup() {
pinMode(Led, OUTPUT); // define LED as output interface
pinMode(buttonpin, INPUT); // define the mercury tilt switch sensor output interface
}

void loop() {
val = digitalRead(buttonpin); // read the values assigned to the digital interface 3 val

// When the mercury tilt switch sensor detects a signal, LED flashes
if (val == HIGH) {
digitalWrite(Led, HIGH);
}
else {
digitalWrite(Led, LOW);
}
}