I constructed a journal which uses a force sensor to turn an integrated reading light on and off when the cover is opened and closed. The journal also plays hello and goodbye musical bits on open and close and occasionally plays a soft intermittent chime when closed for long periods of time - a plea for attention.

Components Used

Breadboard (1)
Arduino Decimila Board (1)
Piezo Speaker (1)
Super-Bright LED with leads (scavenged from an old project)
Resistor (1)
Cable lengths (6)
Jumpers (1)
Moleskine Unruled Journal (1)

 

Images

Arduino & Components sans Journal

 

Journal

 

Integrating Force Sensor and LED into Back Cover

 

 

 

 

Arduino Code

int forcePin = 0; // select the input pin for the force sensor

int speakerPin = 7;

int val = 0;

byte names[] = {'c', 'd', 'e', 'f', 'g', 'a', 'b', 'C'};

int tones[] = {1915, 1700, 1519, 1432, 1275, 1136, 1014, 956};

byte melody[] = "2d2a1f2c2d2a2d2c2f2d2a2c2d2a1f2c2d2a2a2g2p8p8p8p";

byte hello[] = "1c1p1d1p1e1p1f1p1g1p1a1p1b1p1C1p";

byte goodbye[] = "1C1p1b1p1a1p1g1p1f1p1e1p1d1p1c1p";

byte wave[] = "1f1c1f1c";

int count = 0;

int count2 = 0;

int count3 = 0;

int MAX_COUNT = 24;

int statePin = LOW;

boolean isOpen = true;

int waveWait = 0;

void setup() {

pinMode(speakerPin, OUTPUT);

beginSerial(9600);

Serial.println("ready");

digitalWrite(speakerPin, LOW);

val = analogRead(forcePin); // read value from the sensor

if(val > 100) isOpen = false;

}

void loop() {

val = analogRead(forcePin); // read value from the sensor

Serial.print("val=");

Serial.print(val);

Serial.println();

//check to see if the journal has been opened or closed

if(val < 1 && !isOpen){ //light up the LEDs and play welcome sound

playHello();

analogWrite(9, 255);

isOpen = true;

}

else if(val > 100 && isOpen){ //dim LED and play goodbye sound

playGoodbye();

analogWrite(9, 0);

isOpen = false;

}

if(!isOpen){

//play a reminder chime

if(waveWait++%50000 == 0){

playWave();

}

}

}

void playHello(){

playJams(hello,16);

}

void playGoodbye(){

playJams(goodbye,16);

}

void playWave(){

playJams(wave,8);

}

//plays the a series of notes defined in an array

void playJams(byte jams[], int length){

for (count = 0; count < length; count++) {

statePin = !statePin;

for (count3 = 0; count3 <= (jams[count*2] - 48) * 30; count3++) {

for (count2=0;count2<8;count2++) {

if (names[count2] == jams[count*2 + 1]) {

digitalWrite(speakerPin,HIGH);

delayMicroseconds(tones[count2]);

digitalWrite(speakerPin, LOW);

delayMicroseconds(tones[count2]);

}

if (jams[count*2 + 1] == 'p') {

// make a pause of a certain size

digitalWrite(speakerPin, 0);

delayMicroseconds(500);

}

}

}

}

}