#Arduino sensors and switches how to
#Arduino sensors and switches code

How to Program a Keyes KY-020 Tilt Switch Instead of an LED, you can control any other device that’s activated by a 5V high or low signal. LEDs are just a good way to demonstrate what’s happening with the Arduino’s output pins. When the sensor is tilted backwards, the green LED should turn on: Once you connect the tilt sensor and LEDs to the Arduino and upload the code, you should see the red LED turn on when the sensor is tilted forward. This turns on the green LED when the sensor is tilted backwards. The second if statement says “if read equals LOW, then digital write the reverseLED pin HIGH, and digital write the forwardLED pin LOW“. This turns the red LED on when the sensor is tilted forward. So the first if statement says “if read equals HIGH, then digital write the forwardLED pin HIGH, and digital write the reverseLED pin LOW“. Mercury tilt switches output a high signal when tilted forward, and a low signal when tilted backwards. Next we use two if statements to control what happens when the sensorPin goes high and low. In the loop() section, we take a digital read from the sensorPin, and store it in a local variable called read. The sensorPin is an input, the forwardLED pin is an output, and the reverseLED pin is an output as well. In the setup() section we set the pin mode for each pin variable. The third variable is called reverseLED and is set equal to pin 11. Another variable is called forwardLED and is set equal to pin 12. One variable is called sensorPin, and is set equal to pin 10.

#Arduino sensors and switches code

Once the circuit is connected, upload this code to the Arduino: int sensorPin = 10 Īt the top of the sketch, we declare variables for the pins. The Keyes KY-020 tilt switch and the Keyes KY-017 mercury tilt switch have different pin layouts, so connect the circuit according to the sensor you have.įollow this wiring diagram to connect the Keyes KY-017 mercury tilt switch to the Arduino:įollow this diagram to connect the Keyes KY-020 tilt switch: How to Program a Keyes KY-017 Mercury Tilt Switch Let’s build a tilt sensor circuit that turns on a red LED when the sensor is tilted forward, and turns on a green LED when it’s tilted backwards.

And the pin with the minus sign (-) is the ground pin. The Keyes KY-020 tilt switch has a blue chamber with a small metal ball inside that rolls back and forth:ĭepending on the orientation of the sensor, the ball causes two electrical contacts inside the chamber to be either open or closed. The pin with the minus sign (-) is the ground pin. The pin with the S next to it is the signal pin. Here’s a diagram that shows the pins of the Keyes KY-017 mercury tilt switch: But mercury is toxic, so don’t use them in high impact situations where there is a risk of breaking the glass. Mercury tilt switches are more sensitive and reliable than metal ball tilt sensors. When the sensor is tilted forward, the mercury loses contact with one of the electrodes and current stops flowing. When the sensor is tilted backwards, the mercury contacts two electrodes inside the glass bulb and allows current to flow between them. The Keyes KY-017 mercury tilt switch has a small drop of liquid mercury inside a glass bulb: We’re going to be working with two common tilt sensors, the Keyes KY-020 tilt switch, and the Keyes KY-017 mercury tilt switch. We can detect this high or low signal with the Arduino to determine if the sensor is tilted or not. This allows current to flow between the two wires. When the tube is tilted backwards, the ball rolls back and contacts both wires. When the tube is tilted forward, the ball rolls forward and only contacts one wire. Tilt sensors are made up of a plastic or glass tube, with two pieces of wire and a metal ball inside: It includes all of the parts, wiring diagrams, code, and step-by-step instructions for 58 different robotics and internet of things projects that are super fun to build! How Tilt Sensors Work The 3-in-1 Smart Car and IOT Learning Kit from SunFounder has everything you need to learn how to master the Arduino.