Description

By using the pinMode() function, the pins of the Arduino can be configured into the following three modes:

• OUTPUT mode
• INPUT mode
• INPUT_PULLUP mode

In the input pull-up (INPUT_PULLUP) mode, the Arduino will enable the internal pull-up resistor of the pin to protect the circuit. Once the pin is set to input (INPUT) mode, the Arduino internal pull-up resistor will be disabled.

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Set the Arduino pin to output (OUTPUT) mode

When the pin is set to output (OUTPUT) mode, the pin will be in a low resistance state, this means that Arduino can provide current to other circuit components, such as lighting up LEDs.

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Set the Arduino pin to input (INPUT) mode

When the pin is set to input (INPUT) mode, the pin is in a high resistance state (100 MΩ). In this case, the pin can be used to read the potential signal of the sensor.

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Set the Arduino pin to input pullup (INPUT_PULLUP) mode

The Arduino microcontroller comes with internal pull-up resistors. If you need to use this internal pull-up resistor, you can set the pin to input pull-up (INPUT_PULLUP) mode through pinMode().

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Example codes

void setup() {
pinMode(13, OUTPUT); // sets the digital pin 13 as output
}

void loop() {

…

}

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