KY-017 Mercury Tilt Switch Module


Arduino KY-017 mercury tilt switch module, it uses a small mercury ball that completes the circuit when you tilt the module. 


This module consists of a mercury switch, a 680Ω resistor and a LED that will light up when tilt is detected. The mercury ball will open/close the circuit when the module is rotated.

Operating Voltage3.3V to 5.5V

KY-017 Connection Diagram

Connect the Power line (middle) and ground (-) to +5 and GND respectively. Connect signal (S) to pin 3 on the Arduino.

SPin 3
KY-017 Arduino connection diagramclick to enlarge

KY-017 Example code

The following sketch will light up the led on pin 13 of the Arduino when the module is tilted.

int led_pin = 13; // Define the LED interface
int switch_pin = 3; // Definition of mercury tilt switch sensor interface
int val; // Defines a numeric variable

void setup()
	pinMode(led_pin, OUTPUT);
	pinMode(switch_pin, INPUT);

void loop()
	val = digitalRead(switch_pin); // check mercury switch state
	if(val == HIGH)
		digitalWrite(led_pin, HIGH);
		digitalWrite(led_pin, LOW);
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3 years ago

The Fritzing Diagram is wrong: the blue and the black wires on the side of the switch must be swapped. The Signal of the Switch is the third Pin.