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2. Digital Input

This will teach you about digital inputs using buttons and LEDs. This is really important for user input interactions, sensors, and communication!

Materials​

ComponentImage
Breadboard
Jumper wires
Arduino Uno R4 Minima
LED (white, red, blue, or green)
Resistor (220 ohms for the LED, optional if using internal pull-up resistors for buttons)
2 push buttons

Instructions​

  1. Make the following connections using the jumper wires:

Connections​

  • LED: Connect the anode (longer leg) to digital pin 5 and the cathode (shorter leg) to ground through a 220-ohm resistor.
  • Button A: Connect one leg to digital pin 9 and the other leg to ground.
  • Button B: Connect one leg to digital pin 8 and the other leg to ground.
  1. Once wired, upload the following code to your Arduino IDE:

Code​

int ledPin = 5;
int buttonApin = 9;
int buttonBpin = 8;

void setup() {
  pinMode(ledPin, OUTPUT);
  pinMode(buttonApin, INPUT_PULLUP);  
  pinMode(buttonBpin, INPUT_PULLUP);  
}

void loop() {
  if (digitalRead(buttonApin) == LOW) {
    digitalWrite(ledPin, HIGH);
    Serial.println("ON");
  } else if (digitalRead(buttonBpin) == LOW) {
    digitalWrite(ledPin, LOW);
    Serial.println("OFF");
  }
}
  1. Test! Play around with the buttons and customize the digital inputs.
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1. RGB LED Module3. Making Sounds