digitalRead(BUTTON_PIN): this will give us the current state of the button, either LOW or HIGH.

pinMode(BUTTON_PIN, INPUT) : we set pin 4 to INPUT so we can read data from the button.Nothing fancy here, the 2 importants parts are: Let’s write a simple code to print the push button’s value on the Serial Monitor. This is quite simple: you plug one leg of the push button to the ground (GND), and another one – on the other side of the button – to a digital pin. Well, let’s see with 3 different circuits doing the same thing: reading data from a push button. This option is the same as INPUT (you read data from the sensor), but in addition to that, an internal pull up resistor – between 20k and 50k Ohm – is enabled, to keep the signal HIGH by default. The value you’ll get will be HIGH or LOW (binary).Īnd… There’s also a 3rd option: INPUT_PULLUP. INPUT: in this case you’re going to read data from the sensor.OUTPUT: this is to write data to an actuator, for example an LED.You are learning how to use Arduino to build your own projects?Ĭheck out Arduino For Beginners and learn step by step. With Arduino you can use digital pins to either read (binary) data from a sensor, or write (binary) data to an actuator. Conclusion – Arduino INPUT_PULLUP recap.

Using an external resistor instead of Arduino INPUT_PULLUP.

Arduino wire library internal register