How the buttons and LEDs are wired

The shield's three buttons sit on analog pins A1, A2 and A3 and read LOW (0) when pressed. The four LEDs are on digital pins 13, 12, 11 and 10 and are active-low: writing HIGH turns an LED off, writing LOW turns it on. That is just how the board is built.

No library is needed for this one. The sketch defines every pin by name at the top so you are not sprinkling magic numbers through the code, then in loop() reads each button and mirrors it onto its LED, printing to the Serial Monitor as well. The small delay stops the Serial Monitor from flooding.

Copy the #define block into anything else you write for this shield.

Buttons light their LEDs

// Multi-Function Shield: buttons -> LEDs (no library needed)
#define LED_1_PIN 13
#define LED_2_PIN 12
#define LED_3_PIN 11
#define LED_4_PIN 10

#define BUTTON_1_PIN A1
#define BUTTON_2_PIN A2
#define BUTTON_3_PIN A3

void setup() {
  Serial.begin(9600);

  pinMode(LED_1_PIN, OUTPUT);
  pinMode(LED_2_PIN, OUTPUT);
  pinMode(LED_3_PIN, OUTPUT);
  pinMode(LED_4_PIN, OUTPUT);

  pinMode(BUTTON_1_PIN, INPUT);
  pinMode(BUTTON_2_PIN, INPUT);
  pinMode(BUTTON_3_PIN, INPUT);

  // LEDs are active-low: HIGH = off
  digitalWrite(LED_1_PIN, HIGH);
  digitalWrite(LED_2_PIN, HIGH);
  digitalWrite(LED_3_PIN, HIGH);
  digitalWrite(LED_4_PIN, HIGH);
}

void loop() {
  if (digitalRead(BUTTON_1_PIN) == 0) {
    Serial.println("Button 1 pressed");
    digitalWrite(LED_1_PIN, LOW);   // on
  } else {
    digitalWrite(LED_1_PIN, HIGH);  // off
  }

  if (digitalRead(BUTTON_2_PIN) == 0) {
    Serial.println("Button 2 pressed");
    digitalWrite(LED_2_PIN, LOW);
  } else {
    digitalWrite(LED_2_PIN, HIGH);
  }

  if (digitalRead(BUTTON_3_PIN) == 0) {
    Serial.println("Button 3 pressed");
    digitalWrite(LED_3_PIN, LOW);
  } else {
    digitalWrite(LED_3_PIN, HIGH);
  }

  delay(100);
}

Multi-Function Shield: Buttons

How the buttons and LEDs are wired