Arduino Pull Down Resistor

In this tutorial, we will discuss how to use a pull-down resistor with a switch in Arduino.

Using Pull Down Resistor With a Switch in Arduino

If you want to use a switch with Arduino to get input, you have to use a pull-down resistor with the switch because if the pin is not connected to anything, it will read a random value from the environment, which can eighter be LOW or HIGH. In the case of a switch, we want the pin to be HIGH only if the switch is closed, and if it’s open, the pin should read LOW. But if a pull-down resistor is not used with the switch, the pin will read a random value from the environment, which can eighter be LOW or HIGH. A pull-down resistor connects the pin with the ground if the switch is open, so the pin will only read LOW. To connect a pull-down resistor with a switch, check the below figure.

The value of the resistor should be between 1k to 100k. If you use a very low-value resistor, a high current will flow to the power ground when the switch is closed, and it can damage the Arduino. The 5V and GND pins are present in Arduino, so you can use them with your switch and pull-down resistor. If the switch is closed, the pin will be directly connected to the 5V, and the pin will be in HIGH state, and if the switch is open, the pin will be connected to the ground, and the pin will be in LOW state.