Month: November 2024

Inspiration

The WaveSynth project is inspired by the theremin, one of the first electronic instruments, invented in 1920 by Russian physicist Léon Theremin. Known for its eerie, vocal-like sound and its unique, touchless control, the theremin uses two antennas to detect the position of the player’s hands: one antenna controls pitch, and the other controls volume. By moving their hands through electromagnetic fields, players can create smooth, flowing sounds without touching the instrument. This expressive control has influenced generations of musicians and has become iconic in sci-fi, horror, and experimental music.

Concept

The WaveSynth is a gesture-controlled musical instrument that turns hand movements and environmental factors into dynamic sound. Designed to be both intuitive and expressive, the WaveSynth combines multiple sensors—ultrasonic, temperature, and a potentiometer—to create a cohesive interface.

The ultrasonic sensor detects hand distance, adjusting either pitch or volume based on the player’s proximity. The potentiometer serves as a mode selector, allowing the user to switch between pitch and volume control, as well as access different sound effects like vibrato, pulse, and temperature modulation. The temperature sensor adds an additional layer of subtlety, with ambient temperature shifts introducing slight pitch modulations, making the instrument responsive to its surroundings.

List of the hardware components used in the WaveSynth project:

• Arduino Uno
• HC-SR04 Ultrasonic Sonar Sensor (for gesture-based distance measurement)
• TMP36GZ Temperature Sensor (for ambient temperature-based modulation)
• 10k Ohm Potentiometer (for mode and effect selection)
• Piezo Speaker (for sound output)
• Connecting Wires (for connections between components and the Arduino)
• Breadboard (for prototyping and circuit connections)
• 310 Ohm Resistor (for LED circuit)

Schematic Diagram:

Code:

// Pin definitions
const int potPin = A0;            // Analog pin for potentiometer
const int tempPin = A1;           // Analog pin for TMP36GZ temperature sensor
const int trigPin = 3;            // Digital pin for sonar trigger
const int echoPin = 4;            // Digital pin for sonar echo
const int speakerPin = 9;         // Digital pin for speaker
const int ledPin = 5;             // Digital pin for LED (PWM-enabled)

// Variables
int effectType = 0;               // Tracks which effect is active (0: none, 1: vibrato, 2: pulse, 3: temperature modulation)

void setup() {
  pinMode(speakerPin, OUTPUT);      // Speaker as output
  pinMode(trigPin, OUTPUT);         // Sonar trigger as output
  pinMode(echoPin, INPUT);          // Sonar echo as input
  pinMode(ledPin, OUTPUT);          // LED as output
  Serial.begin(9600);               // For debugging output
}

// Function to read distance from the sonar sensor
long readDistance() {
  digitalWrite(trigPin, LOW);
  delayMicroseconds(2);
  digitalWrite(trigPin, HIGH);
  delayMicroseconds(10);
  digitalWrite(trigPin, LOW);

  // Measure the pulse duration on the echo pin
  long duration = pulseIn(echoPin, HIGH);
  
  // Calculate distance in centimeters
  long distance = duration * 0.034 / 2;
  return distance;
}

// Function to read temperature from the TMP36GZ
float readTemperature() {
  int tempReading = analogRead(tempPin);             // Read analog value from TMP36
  float voltage = tempReading * (5.0 / 1023.0);      // Convert reading to voltage (0-5V)
  float temperatureC = (voltage - 0.5) * 100.0;      // Convert voltage to temperature in Celsius
  return temperatureC;
}

void loop() {
  // Potentiometer to control mode and effect
  int potValue = analogRead(potPin);                  // Read potentiometer (0-1023)
  bool pitchMode = potValue < 512;                    // Below midpoint is pitch mode, above is volume mode
  
  // Determine the effect based on the potentiometer value ranges
  if (potValue < 256) {
    effectType = 0;                                   // No effect
  } else if (potValue < 512) {
    effectType = 1;                                   // Vibrato
  } else if (potValue < 768) {
    effectType = 2;                                   // Pulse
  } else {
    effectType = 3;                                   // Temperature modulation
  }

  // Read sonar distance and map to a lower pitch range for soothing tones
  long distance = readDistance();                     // Distance in cm
  int baseToneValue = pitchMode ? map(distance, 5, 50, 150, 600) : 440;  // Map distance to pitch if in Pitch Mode
  
  // Control LED brightness based on distance
  int ledBrightness = map(distance, 5, 50, 255, 0);   // Closer is brighter (5 cm = max brightness)
  ledBrightness = constrain(ledBrightness, 0, 255);   // Constrain within 0-255
  analogWrite(ledPin, ledBrightness);                 // Set LED brightness
  
  // Read temperature and map it to a gentle pitch effect
  float temperature = readTemperature();
  int tempEffect = map(temperature, 20, 35, 20, 80);  // Map temperature to subtle pitch modulation
  
  // Debug output to Serial Monitor
  Serial.print("Distance: ");
  Serial.print(distance);
  Serial.print(" cm, LED Brightness: ");
  Serial.print(ledBrightness);
  Serial.print(", Pot Value: ");
  Serial.print(potValue);
  Serial.print(", Effect Type: ");
  Serial.print(effectType);
  Serial.print(", Temperature: ");
  Serial.print(temperature);
  Serial.println(" C");

  // Play sound based on the selected effect type
  switch (effectType) {
    case 0: // No effect
      tone(speakerPin, baseToneValue); // Basic tone based on distance
      break;
    
    case 1: // Smooth Vibrato
      for (int i = 0; i < 20; i++) {
        int vibratoTone = baseToneValue + (sin(i * 0.3) * 10); // Soft vibrato effect with lower amplitude
        tone(speakerPin, vibratoTone, 50); // Short tone bursts for vibrato
        delay(20); // Slightly slower delay for soothing vibrato effect
      }
      break;
      
    case 2: // Gentle Pulse
      tone(speakerPin, baseToneValue);      // Play base tone continuously
      analogWrite(speakerPin, 128);         // Soft fade for pulse effect
      delay(100);                           // Adjust pulse duration for gentler effect
      noTone(speakerPin);                   // Turn off sound briefly to create pulse
      delay(100);                           // Wait before next pulse
      break;
      
    case 3: // Temperature Modulation
      int tempModulatedTone = baseToneValue + tempEffect;  // Adjust pitch slightly based on temperature
      tone(speakerPin, tempModulatedTone); // Continuous tone with slight modulation
      delay(200); // Keep tone smooth
      break;
  }
  
  delay(50); // Small delay for stability
}

Media:

Working Process:

1. Initial Setup and Calibration:
   1. When powered on, the Arduino initializes all sensors and components, including the ultrasonic sensor, temperature sensor, potentiometer, and speaker.
   2. The potentiometer’s position is read to determine the initial mode (Pitch or Volume) and effect (Vibrato, Pulse, Temperature Modulation, or None). The instrument is ready to interpret the player’s gestures and environmental inputs to start producing sound.
2. Gesture Detection and Distance Measurement:
   1. The player positions their hand near the ultrasonic sensor and moves it to change sound properties.
   2. The ultrasonic sensor measures the distance between the player’s hand and the sensor by sending out an ultrasonic pulse and timing how long it takes for the pulse to bounce back.
   3. The distance value is calculated and then mapped to control either pitch or volume based on the selected mode:
      1. Pitch Mode: The distance between the sensor and the player’s hand changes the pitch of the sound. Closer hand positions produce higher pitches, while farther positions result in lower pitches.
      2. Volume Mode: In this mode, the distance controls the volume of the sound. Closer distances yield louder sounds, and farther distances make the sound quieter.
3. Sound Modification through Effects:
   1. The potentiometer serves as a selector for various sound effects that add dynamic layers to the base tone. Depending on the potentiometer’s position, the following effects are applied:
      1. No Effect (Basic Tone): The sound responds directly to the pitch or volume based on the hand distance with no additional modulation.
      2. Vibrato Effect: The instrument adds a wave-like oscillation to the pitch, producing a gentle, undulating sound. This effect is applied continuously, allowing the sound to vary smoothly.
      3. Pulse Effect: The sound output is pulsed, creating a rhythmic on-and-off pattern. This effect provides a percussive quality, ideal for rhythmic play.
      4. Temperature Modulation: Ambient temperature subtly adjusts the pitch, creating an atmospheric and evolving sound that changes with the surrounding environment. This effect responds more slowly, allowing the sound to naturally vary over time.
4. Environmental Adaptation with Temperature Modulation:
   1. When Temperature Modulation is selected, the temperature sensor reads the ambient temperature. The Arduino then uses this temperature reading to modulate the pitch subtly.
   2. For example, warmer temperatures gradually increase the pitch, while cooler temperatures lower it. This effect is gradual and blends naturally with the other sound properties, adding a unique, ambient quality to the instrument’s sound.
5. Real-Time Sound Output:
   1. The piezo speaker produces sound based on the interpreted data, transforming distance measurements, temperature readings, and selected effects into real-time audio.
   2. The speaker continuously updates its output to reflect the current settings and environmental conditions, providing an immediate response to hand movements and mode changes.
   3. As the player moves their hand closer or farther from the ultrasonic sensor, the sound changes instantly in pitch or volume. Additionally, adjustments to the potentiometer instantly modify the effect applied to the sound.
6. Interactive Feedback Loop:
   1. The player continuously interacts with the WaveSynth by adjusting their hand position, changing the potentiometer setting, and experiencing the evolving sound.
   2. This interactive feedback loop allows the player to dynamically control and modify the instrument’s output, creating an immersive musical experience that feels responsive and alive.

Future Improvement and Challenges

One of the primary challenges encountered was calibrating the sensors to respond smoothly and accurately to the user’s hand movements. Fine-tuning the pitch range and ensuring that the effects—such as vibrato and pulse—blended naturally with the sound output took several iterations to achieve a pleasing result.

The temperature sensor was tough to work with on the Arduino board.

Additionally, integrating digital sound synthesis or MIDI compatibility would enable users to connect the WaveSynth with other musical devices or software, greatly expanding its versatility as a tool for music creation.

Another possible enhancement could be the inclusion of LEDs or other visual feedback elements to indicate mode selection and provide dynamic light effects that correspond to the sound output. This would enhance the visual aspect of the instrument, making it even more engaging for live performances.

As a reader and technology enthusiast, I find Bret Victor’s “A Brief Rant on the Future of Interaction Design” to be a thought-provoking critique of current trends in human-computer interaction. Victor’s argument against “Pictures Under Glass” technology and her call for more tactile, three-dimensional interfaces resonates with my own experiences and frustrations with touchscreen devices.Victor’s vivid descriptions of how we use our hands to manipulate objects in the real world highlight the limitations of current touchscreen interfaces. I’ve often felt that something was missing when using my smartphone or tablet, and Victor’s examples of reading a book or drinking from a glass perfectly capture that sense of disconnection. The richness of tactile feedback we get from physical objects is indeed absent in our flat, glassy screens

As someone who uses technology daily, I’m excited by the possibility of interfaces that better utilize our hands’ capabilities and even our entire bodies.Victor’s argument extends beyond just hands to encompass our entire bodies, noting that we have “300 joints” and “600 muscles”

This resonates with my own experiences of how we naturally use our whole bodies when interacting with the physical world. I’ve often felt constrained by the limited range of motion required to use current devices, and the idea of more holistic, full-body interfaces is intriguing.While I appreciate Victor’s vision, I also recognize the practical challenges of implementing more tactile and three-dimensional interfaces. Issues of cost, durability, and scalability would need to be addressed. Additionally, I believe the future of interaction design will likely involve a combination of approaches, including enhanced haptic feedback, hybrid interfaces that combine touchscreens with physical controls, and multimodal interaction incorporating touch, voice, and gesture.

Yup, I was watching “Minions: Rise of Gru” over the weekend in order to find some inspiration for this week’s project, and I sure found the basis of my project when I watched this:

Concept

I decided on using a wheatstone bridge setup with two variable resistors (one photoresistor, and ‘the’ banana), and find the absolute difference between the two values and emit different sounds. I also decided to use a potentiometer to determine the pitch of the notes.

Apart from that, the user also has an option to not use the photoresistor at all by toggling the fixed 330 Ohm resistor in its place.

Material Required

• Arduino Board
• Jumper Wires
• Breadboard
• Potentiometer
• 10k Ohm Resistors
• 330 Ohm Resistors
• SEN-09088 Photocell
• Potentiometer
• Banana

Schematic

Demonstration Video

Code

This Arduino code reads the voltage difference between V1 and V2, maps it to a frequency for the speaker, and uses a potentiometer to shift the octave.

// Pin configuration
const int v1Pin = A1;       // V1 of Wheatstone bridge
const int v2Pin = A2;       // V2 of Wheatstone bridge
const int potPin = A3;      // Potentiometer for octave control
const int speakerPin = 9;   // Speaker pin

// Variables for calibration and tuning
float baseFrequency = 220.0;  // Base frequency in Hz for a low A note
float maxVoltageDifference = 5.0;  // Maximum expected voltage difference (adjust as necessary)
int maxOctaveShift = 7;       // Maximum number of octaves to shift

void setup() {
  Serial.begin(9600);
  pinMode(v1Pin, INPUT);
  pinMode(v2Pin, INPUT);
  pinMode(potPin, INPUT);
  pinMode(speakerPin, OUTPUT);
}

void loop() {
  // Read voltage difference across V1 and V2
  float v1 = analogRead(v1Pin) * (5.0 / 1023.0);
  float v2 = analogRead(v2Pin) * (5.0 / 1023.0);
  float voltageDifference = abs(v1 - v2);

  // Map voltage difference to a frequency
  float noteFrequency = map(voltageDifference * 100, 0, maxVoltageDifference * 100, baseFrequency, baseFrequency * 2);

  // Read potentiometer and map to octave shift
  int potValue = analogRead(potPin);
  int octaveShift = map(potValue, 0, 1023, 0, maxOctaveShift);

  // Apply octave shift to the frequency
  noteFrequency *= pow(2, octaveShift);

  // Output the frequency to the speaker
  tone(speakerPin, noteFrequency);
  
  // Debugging output
  Serial.print("Voltage Difference: ");
  Serial.print(voltageDifference);
  Serial.print(" V, Frequency: ");
  Serial.print(noteFrequency);
  Serial.println(" Hz");

  delay(50);  // Delay for bouncing error
}

Conclusion and Reflection

Constructing this banana-powered musical instrument was a fun and an instructive process combining artistic design with technological principles. By using a Wheatstone bridge, I was quite free to play around on how I wanted to shape my music instrument.

Challenges Faced

1. Stabilizing the Output:
One major challenge was stabilizing the audio output, as random values were being read when the pencil jockey wasn’t in contact with the banana. This caused unwanted noises and a “wobbling” effect. To overcome this, I decided that I needed a pulldown resistor (here I used 2 Mega Ohms) to avoid reading noise in the Analog Pin A2

2. Mapping Voltage to Frequency Accurately:
Mapping the voltage difference to frequencies that sound musical took some experimentation. Adjusting the base frequency and range, as well as the octave shift, required fine-tuning to achieve the desired range of notes without distorting the sound.

Concept 

In this assignment, I collaborated with @Nelson and we both love Christmas. The famous song Jingle Bells brings memories of the the times. So we explored various possibilities and decided to come up with speed variation of the Jingle Bells melody with respect to distance.

Here is the demonstration Video:

Schematic 

Here is the Schematic  for our Arduino connections:

Code:

In the implementation of our our idea, we searched for possible combinations of the notes and durations to match the Jingle Bells melody and stored them in an array. We then implemented the code mapping distance with durations. The variations in durations for each note make it seem playing faster or slower. Here is the code:

#include "pitches.h"
#define ARRAY_LENGTH(array) (sizeof(array) / sizeof(array[0]))

// Notes and Durations to match the Jingle Bells 
int JingleBells[] = 
{
  NOTE_E4, NOTE_E4, NOTE_E4, NOTE_E4, NOTE_E4, NOTE_E4, NOTE_E4, NOTE_G4,
  NOTE_C4, NOTE_D4, NOTE_E4, NOTE_F4, NOTE_F4, NOTE_F4, NOTE_F4, NOTE_F4,
  NOTE_E4, NOTE_E4, NOTE_E4, NOTE_E4, NOTE_E4, NOTE_D4, NOTE_D4, NOTE_E4,
  NOTE_D4, NOTE_G4, NOTE_E4, NOTE_E4, NOTE_E4, NOTE_E4, NOTE_E4, NOTE_E4, NOTE_E4, NOTE_G4,
  NOTE_C4, NOTE_D4, NOTE_E4, NOTE_F4, NOTE_F4, NOTE_F4, NOTE_F4, NOTE_F4,
  NOTE_E4, NOTE_E4, NOTE_E4, NOTE_E4, NOTE_E4, NOTE_D4, NOTE_D4, NOTE_E4,
  NOTE_D4, NOTE_G4,
};

int JingleBellsDurations[] = {
  4, 4, 4, 4, 4, 4, 4, 4,
  4, 4, 4, 4, 4, 4, 4, 4,
  4, 4, 4, 4, 4, 4, 4, 4,
  4, 4, 4, 4, 4, 4, 4, 4, 4, 4,
  4, 4, 4, 4, 4, 4, 4, 4,
  4, 4, 4, 4, 4, 4, 4, 4,
  4, 4
};

const int echoPin = 7;
const int trigPin = 8;;
const int Speaker1 = 2;
const int Speaker2 = 3;
int volume;

void setup() 
{
// Initialize serial communication:
  Serial.begin(9600);
  pinMode(echoPin, INPUT);
  pinMode(trigPin, OUTPUT);
  pinMode(Speaker1,OUTPUT);
}

void loop() 
{
  long duration,Distance;
  
// Distance Sensor reading
  digitalWrite(trigPin, LOW);
  delayMicroseconds(2);
  digitalWrite(trigPin, HIGH);
  delayMicroseconds(5);
  digitalWrite(trigPin, LOW);
  duration = pulseIn(echoPin, HIGH);
  Distance = microsecondsToCentimeters(duration);

// Map Distance to volume range (0 to 255)
  volume = map(Distance, 0, 100, 0, 255);  
  volume = constrain(volume, 0, 255); 

// Play melody with adjusted volume


 playMelody(Speaker1 , JingleBells, JingleBellsDurations, ARRAY_LENGTH(JingleBells), volume);
  
// Debug output to Serial Monitor
  Serial.print("Distance: ");
  Serial.print(Distance);
  Serial.print("    Volume: ");
  Serial.print(volume);
  Serial.println();
}
// Get Centimeters from microseconds of Sensor
long microsecondsToCentimeters(long microseconds) 
{
  return microseconds / 29 / 2;
}
// PlayMelody function to accept volume and adjust note duration
void playMelody(int pin, int notes[], int durations[], int length, int volume) 
{
  for (int i = 0; i < length; i++) 
  {
// Adjust the note Duration based on the volume
    int noteDuration = (1000 / durations[i]) * (volume / 255.0);  

// Play the note with adjusted Durations
    tone(pin, notes[i], noteDuration);
// Delay to separate the notes
    delay(noteDuration * 1.3);  
    noTone(pin); 
  }
}

Reflection

This week’s assignment was especially interesting because we had a chance to collaborate on the project and combine our imagination and skills to create something original. I really enjoyed working with @Nelson. We worked great as a team by first coming up with an idea and then adjusting the concept to choose the ideal balance between randomness and something ordinary to achieve the final result.

I believe that this project has a lot of potential for future improvements, and perhaps I will use some parts of this week’s assignment for my future ideas and projects. Looking forward to the next weeks of the course!