# Lab: Musical Frequency Explorer ## **Objective** Create a music player system using the TK37 passive buzzer to generate tones, play melodies, and create musical compositions with different frequencies and timing. ## **Required Components**  1. **Lonely Binary UNO R3** - Main Arduino board 2. **TinkerBlock UNO R3 Shield** - Expansion shield that plugs onto the UNO R3 3. **TinkerBlock TK37** - Passive Buzzer Module ## **Theory** ### **Passive Buzzer vs Active Buzzer** - **Active Buzzer**: Built-in oscillator, only on/off control - **Passive Buzzer**: No oscillator, requires frequency control - **Frequency Control**: Can generate any frequency (20Hz - 20kHz) - **Tone Generation**: Uses `tone()` function for precise frequency control ### **Musical Notes and Frequencies** - **A4 (440Hz)**: Standard reference note - **Octave Relationship**: Each octave doubles the frequency - **Note Frequencies**: Mathematical relationship between notes - **Tempo**: Beats per minute (BPM) for rhythm control ### **Music Theory Basics** - **Notes**: A, B, C, D, E, F, G (with sharps/flats) - **Octaves**: Different pitch ranges (C4, C5, C6, etc.) - **Duration**: Whole, half, quarter, eighth notes - **Rest**: Silence periods in music ## **Wiring Instructions** ### **TK37 Passive Buzzer Pinout** - **GND** → Arduino GND - **VCC** → Arduino 5V - **NC** → No Connection - **Signal** → Arduino Digital Pin D7 ### **Connection Diagram**  ``` UNO R3 + Shield └── Digital Pin D7 ──→ TK37 Signal ``` ## **Basic Tone Generation Code** ```cpp // Basic Tone Generation with TK37 Passive Buzzer // Pin definitions #define BUZZER_PIN 7 // TK37 Passive Buzzer on D9 // Musical note frequencies (Hz) #define NOTE_C4 262 #define NOTE_D4 294 #define NOTE_E4 330 #define NOTE_F4 349 #define NOTE_G4 392 #define NOTE_A4 440 #define NOTE_B4 494 #define NOTE_C5 523 #define NOTE_D5 587 #define NOTE_E5 659 #define NOTE_F5 698 #define NOTE_G5 784 #define NOTE_A5 880 #define NOTE_B5 988 void setup() { // Initialize serial communication Serial.begin(9600); Serial.println("TK37 Passive Buzzer Music Player"); Serial.println("================================="); // Initialize buzzer pin pinMode(BUZZER_PIN, OUTPUT); delay(1000); Serial.println("Playing basic tones..."); Serial.println(); } void loop() { // Play ascending scale Serial.println("Playing ascending C major scale:"); tone(BUZZER_PIN, NOTE_C4, 500); delay(600); tone(BUZZER_PIN, NOTE_D4, 500); delay(600); tone(BUZZER_PIN, NOTE_E4, 500); delay(600); tone(BUZZER_PIN, NOTE_F4, 500); delay(600); tone(BUZZER_PIN, NOTE_G4, 500); delay(600); tone(BUZZER_PIN, NOTE_A4, 500); delay(600); tone(BUZZER_PIN, NOTE_B4, 500); delay(600); tone(BUZZER_PIN, NOTE_C5, 500); delay(600); noTone(BUZZER_PIN); delay(1000); // Play descending scale Serial.println("Playing descending C major scale:"); tone(BUZZER_PIN, NOTE_C5, 500); delay(600); tone(BUZZER_PIN, NOTE_B4, 500); delay(600); tone(BUZZER_PIN, NOTE_A4, 500); delay(600); tone(BUZZER_PIN, NOTE_G4, 500); delay(600); tone(BUZZER_PIN, NOTE_F4, 500); delay(600); tone(BUZZER_PIN, NOTE_E4, 500); delay(600); tone(BUZZER_PIN, NOTE_D4, 500); delay(600); tone(BUZZER_PIN, NOTE_C4, 500); delay(600); noTone(BUZZER_PIN); delay(2000); Serial.println("Scale complete. Restarting..."); Serial.println(); } ``` ## **Code Explanation** ### **Pin Configuration and Constants** ```cpp #define BUZZER_PIN 7 // TK37 Passive Buzzer on D7 ``` - **BUZZER_PIN**: Defines the digital pin (D7) connected to the TK37 buzzer - **Note Definitions**: Pre-defined frequencies for musical notes in Hz - **Frequency Range**: C4 (262Hz) to B5 (988Hz) covers two octaves ### **Setup Function** ```cpp void setup() { Serial.begin(9600); pinMode(BUZZER_PIN, OUTPUT); } ``` - **Serial Communication**: Initializes serial monitor for debugging - **Pin Configuration**: Sets buzzer pin as OUTPUT for tone generation - **System Initialization**: Waits 1 second for system stabilization ### **Tone Generation Function** ```cpp tone(BUZZER_PIN, NOTE_C4, 500); delay(600); ``` - **tone() Function**: Generates specific frequency for specified duration - **Frequency Parameter**: Musical note frequency in Hz - **Duration Parameter**: How long to play the note (500ms) - **Delay Timing**: 600ms total delay ensures note completion plus pause ### **Scale Playing Logic** ```cpp // Ascending scale: C4 → D4 → E4 → F4 → G4 → A4 → B4 → C5 // Descending scale: C5 → B4 → A4 → G4 → F4 → E4 → D4 → C4 ``` - **Note Sequence**: Follows C major scale pattern - **Octave Transition**: C4 to C5 shows octave relationship - **Consistent Timing**: 500ms note duration with 600ms total delay - **Scale Completion**: noTone() stops sound between scales ### **Key Programming Concepts** #### **Frequency Control** - **Precise Frequencies**: Each note has exact mathematical frequency - **Octave Relationship**: Each octave doubles the frequency (C4=262Hz, C5=523Hz) - **Musical Accuracy**: Frequencies match standard musical tuning (A4=440Hz) #### **Timing Control** - **Note Duration**: 500ms provides clear, audible notes - **Pause Timing**: 100ms pause between notes for clear separation - **Scale Rhythm**: Consistent timing creates musical rhythm - **Loop Structure**: 2-second pause between scale repetitions #### **Serial Output** - **Debug Information**: Shows which scale is currently playing - **Progress Tracking**: Displays current operation status - **User Feedback**: Confirms system is working correctly - **Educational Value**: Helps understand musical concepts ### **Passive Buzzer Characteristics** - **Frequency Control**: Can generate any frequency from 20Hz to 20kHz - **Precise Tones**: tone() function provides accurate frequency generation - **No Built-in Oscillator**: Requires external frequency control - **Musical Flexibility**: Can play any musical note or custom frequency - **Volume Control**: Limited volume control through frequency adjustment ## **Expected Output** ### **Serial Monitor Output** ``` TK37 Passive Buzzer Music Player ================================= Playing basic tones... Playing ascending C major scale: [Ascending musical scale plays: C4, D4, E4, F4, G4, A4, B4, C5] Playing descending C major scale: [Descending musical scale plays: C5, B4, A4, G4, F4, E4, D4, C4] Scale complete. Restarting... ``` ### **Audio Output** - **Ascending Scale**: Clear, ascending musical notes from low to high pitch - **Descending Scale**: Clear, descending musical notes from high to low pitch - **Note Clarity**: Each note should be distinct and recognizable - **Rhythm**: Consistent timing creates musical rhythm - **Octave Transition**: Clear difference between C4 and C5 octaves ### **Visual Indicators** - **No Visual Output**: This lab focuses on audio generation - **Serial Monitor**: Shows program status and progress - **Arduino LED**: May blink during program execution ## **Troubleshooting** ### **No sound from buzzer:** - **Check Wiring**: Verify TK37 is connected to D7 pin - **Power Supply**: Ensure 5V and GND connections are secure - **Pin Configuration**: Confirm pinMode(BUZZER_PIN, OUTPUT) is set - **Test Simple Tone**: Try tone(BUZZER_PIN, 440, 1000) for basic test ### **Distorted or weak sound:** - **Power Supply**: Check if 5V supply is stable and sufficient - **Wiring Quality**: Ensure all connections are secure and clean - **Frequency Range**: Test with different frequencies (200-2000Hz) - **Buzzer Quality**: Verify TK37 module is functioning properly ### **Incorrect note frequencies:** - **Note Definitions**: Check that note frequencies are correctly defined - **Mathematical Accuracy**: Verify frequencies follow musical standards - **Octave Relationship**: Ensure C5 is exactly double C4 frequency - **Reference Note**: Confirm A4 = 440Hz for proper tuning ### **Timing issues:** - **Note Duration**: Adjust 500ms duration if notes are too short/long - **Pause Timing**: Modify 100ms pause for different rhythm - **Scale Speed**: Change delay values to adjust overall tempo - **Loop Timing**: Adjust 2-second pause between scale repetitions ### **Serial monitor issues:** - **Baud Rate**: Ensure Serial.begin(9600) matches monitor setting - **USB Connection**: Check Arduino is properly connected to computer - **Driver Issues**: Verify Arduino drivers are installed correctly - **Port Selection**: Select correct COM port in Arduino IDE ## **Applications** ### **Educational** - **Music Theory**: Learn about musical notes and frequencies - **Frequency Relationships**: Understand octave and scale relationships - **Programming**: Practice timing and control structures - **Audio Engineering**: Introduction to digital audio generation ### **Entertainment** - **Musical Instruments**: Create simple electronic instruments - **Game Development**: Add sound effects and musical elements - **Interactive Projects**: Sound feedback for user interactions - **Performance Art**: Audio-visual installations and performances ### **Commercial** - **Product Testing**: Audio feedback for device testing - **Alarm Systems**: Musical alarm tones and notifications - **User Interfaces**: Audio confirmation for button presses - **Accessibility**: Audio cues for visually impaired users ### **Prototyping** - **Audio Prototypes**: Quick audio feedback during development - **Concept Testing**: Validate audio requirements early - **User Experience**: Test audio interaction patterns - **Integration Testing**: Verify audio system integration ## **Customization Ideas** ### **Add More Musical Features:** - **Additional Notes**: Include sharps, flats, and more octaves - **Different Scales**: Implement minor, pentatonic, or blues scales - **Chords**: Play multiple notes simultaneously - **Arpeggios**: Play notes in sequence to create chord-like effects ### **Enhance Timing Control:** - **Variable Tempo**: Adjustable speed for different musical styles - **Rhythm Patterns**: Implement different rhythmic patterns - **Accent Notes**: Emphasize certain notes with longer duration - **Syncopation**: Create off-beat rhythmic patterns ### **Add Interactive Elements:** - **Button Control**: Use buttons to trigger different scales - **Potentiometer Control**: Adjust tempo or note selection with analog input - **Light Sensor**: Change scales based on light intensity - **Motion Sensor**: Trigger music with movement detection ### **Advanced Features:** - **Melody Storage**: Store and play complete melodies - **Random Generation**: Create random musical sequences - **Pattern Recognition**: Learn and repeat user input patterns - **MIDI Integration**: Connect to MIDI devices for professional music creation ## **Next Steps** - **Learn Music Theory**: Study musical scales, chords, and composition - **Explore Advanced Libraries**: Investigate Arduino music libraries - **Build Musical Instruments**: Create complete electronic instruments - **Study Audio Processing**: Learn about digital signal processing - **Experiment with Effects**: Add reverb, echo, or other audio effects ## **Resources** - **Musical Frequencies**: Standard note frequency tables and calculators - **Music Theory**: Basic music theory and composition principles - **Arduino Tone Library**: Advanced tone generation and control - **Audio Engineering**: Digital audio processing and synthesis concepts - **Electronic Music**: History and techniques of electronic music creation