Using the Mercury Open Optical Module KY-017 with Arduino

Introduction

In this tutorial, we will learn about the KY-017 module, what is a mercury switch and we will build a simple project to detect if the KY-017 module is tilted using an Arduino.

Mercury Open Optical Module KY-017

The KY-017 Module will be our main component for this tutorial. This module has a mercury switch and mounted on a breakout board with an LED and resistor. Figure 1 shows the module as seen in fritzing.

Pin Out:

The KY-017 module has three pins.

What is a mercury switch?

A mercury switch has a mercury blob as a means to close its internal contacts. If the switch is level, the mercury bridges the 2 contact points. But if the switch is tilted, the mercury moves on one side and the contact points are open.

Project: Arduino Tilt Indicator

After learning about the KY-017 module and the mercury switch, it is now time to build a project using the module. Our project will be a visual indicator when the KY-017 module is tilted.

Project Components

For this project, we need the following components:

• Arduino Uno board (1 pc.)
• KY-017 Mercury Open Optical Module (1 pc.)
• Jumper wires

Wiring Diagram

Figure 2 shows the connection between the Arduino Uno and the KY-017 Mercury Open Optical Module.

The KY-017 module pins are connected to the Arduino Uno board as follows:

Code

Below is the Arduino sketch for our project. I have added comments to explain important parts of the code. Save the code as KY-017.ino and upload it to your Arduino board.

// Arduino and KY-017 module

void setup() {
  pinMode(8, INPUT);  // module is connected to pin 8
  pinMode(13, OUTPUT);  // built-in LED
}

void loop() {
  if (digitalRead(8) == HIGH) { // if module is tilted, pin 8's state is HIGH
    digitalWrite(13, HIGH);     // switch On LED
  }
  else {
    digitalWrite(13, LOW);     // switch On LED
  }
}

Project Test

Apply power to your Arduino Uno board. The Arduino’s built-in LED will light up when KY-017 is tilted.