Assignment: Input / Output Coincidence Lab Assignment

Collaborators:

Description:

This lab was intended to explore the use of input and output in the same device.

The concept was a sleeping baby.  He wakes up and cries if someone bumps the table, and depending on the time of day, has a different pitched cry.

Here I used a piezo as a 'shock sensor' to determine when and how hard the object was hit and a second piezo to generate noise (duration depending on how hard it was 'startled').  A light sensor was also used to determine time of day (as a function of light).

Components Used:

* (1) Plastic doll
* (2) Piezo speakers
* (1) Photocell
* Arduino board
* USB Cable

Sample code:

/* 303 Emulator (Tappable Theremin)
 * -----------
 * Uses a piezo as a knock sensor and light sensor for tone
 * Piezo read modeled from http://todbot.com/arduino/sketches/piezo_read/piezo_read.pde
*/

// input
int knockPin = 0;
int pitchPin = 1;

// output
int speakerPin = 7;
int ledPin = 13;

int THRESHOLD = 100;  // set minimum value that indicates a knock

int knock = 0;       // variable to store the value coming from the knock sensor
int pitch = 0;       // variable to store from the value coming from the light sensor
int t = 0;         // the "time" measured for how long the knock lasts

void setup() {
  pinMode(ledPin, OUTPUT);
  pinMode(speakerPin, OUTPUT);
  Serial.begin(9600);
  Serial.println("ready");      // indicate we're waiting
}


void loop() {
  digitalWrite(ledPin,LOW);         // indicate we're waiting
  digitalWrite(speakerPin,LOW);     // indicate we're waiting

  knock = analogRead(knockPin);   // read piezo
  pitch = analogRead(pitchPin)/4;   // read pitch
 
  if( knock >= THRESHOLD ) {      // is it bigger than our minimum?
    
    digitalWrite(ledPin, HIGH);   // tell the world

    for( int i=0; i<knock; i++ ) {  // play it for 50 cycles
    
      for ( int j=0; j<50; j++ ) { 
        digitalWrite(speakerPin, HIGH);
        delayMicroseconds(pitch);
        digitalWrite(speakerPin, LOW);
        delayMicroseconds(pitch);
      }
    }  
  
    Serial.print("knock:");
    Serial.print(knock);
    Serial.print(" pitch:");
    Serial.println(pitch);
    Serial.println();   
   
    t = 0;  
    while(analogRead(knockPin) >= (THRESHOLD/2)) {
      t++;
    } // wait for it to go LOW  (with a little hysteresis)
    if(t!=0) 
      Serial.println(t);   
   
      
  }
}

Arduino Layout: