Arduino Metronome Project

Prepare the Arduino IDE and verify your board is working.

1. Connect your Arduino Uno to your computer via USB.
2. Open the Arduino IDE. Select the correct board (Tools → Board → Arduino Uno) and port (Tools → Port).
3. Upload a simple blink sketch to confirm everything works (File → Examples → 01.Basics → Blink).

Connect a pushbutton to control tempo changes.

1. Place the pushbutton on your breadboard so its pins span the center divide.
2. Connect one side of the button to Arduino digital pin 2 using a jumper wire.
3. Connect the same side to GND through a 10kΩ resistor (pull-down configuration).
4. Connect the other side of the button to 5V.

Add audio and visual feedback for each beat.

1. Connect the piezo buzzer's positive (red) wire to Arduino digital pin 8. Connect its negative (black) wire to GND.
2. Place an LED on the breadboard. Connect the long leg (anode) to Arduino digital pin 13 through a 330Ω or 470Ω resistor.
3. Connect the LED's short leg (cathode) to GND.

Program the Arduino to produce beats at adjustable tempos.

1. Open a new sketch in the Arduino IDE and paste the code below.
2. Click the Upload button (right arrow icon) to upload the sketch to your Arduino.

// Arduino Metronome Project
// Adjustable tempo using button, piezo buzzer, and LED

const int buttonPin = 2;
const int ledPin = 13;
const int piezoPin = 8;

int tempo = 120; // Initial tempo (beats per minute)
int buttonState = 0;
int lastButtonState = 0;
unsigned long previousMillis = 0;

void setup() {
  pinMode(buttonPin, INPUT);
  pinMode(ledPin, OUTPUT);
  pinMode(piezoPin, OUTPUT);
  Serial.begin(9600);
}

void loop() {
  unsigned long currentMillis = millis();
  unsigned long interval = 60000 / tempo; // Calculate interval from tempo
  
  // Check if it's time for a beat
  if (currentMillis - previousMillis >= interval) {
    previousMillis = currentMillis;
    beat();
  }
  
  // Read button to adjust tempo
  buttonState = digitalRead(buttonPin);
  if (buttonState == HIGH && lastButtonState == LOW) {
    tempo += 10;
    if (tempo > 240) tempo = 60; // Wrap around after 240 BPM
    Serial.print("Tempo: ");
    Serial.println(tempo);
    delay(200); // Debounce delay
  }
  lastButtonState = buttonState;
}

void beat() {
  digitalWrite(ledPin, HIGH);
  tone(piezoPin, 1000, 50); // 1000 Hz tone for 50ms
  delay(50);
  digitalWrite(ledPin, LOW);
}

Verify the metronome beats and button control work.

1. Watch the LED and listen to the piezo buzzer. They should pulse in sync at regular intervals.
2. Press the button. The tempo should increase by 10 BPM each time you press it.
3. Open the Serial Monitor (Tools → Serial Monitor) to see the current tempo displayed.

Experiment with tempo range, tone pitch, or LED patterns.

1. Change the initial tempo by editing the line `int tempo = 120;` to a different value (e.g., 80 or 160).
2. Adjust the buzzer pitch by changing the `tone(piezoPin, 1000, 50);` line. Try 500 (lower pitch) or 2000 (higher pitch).
3. Add a second LED or change the LED flash duration by adjusting the `delay(50);` in the `beat()` function.