hearbeat-hoodie.ino

/* Heartbeat Hoodie  
 *
 * LED code drawn from Arduino example 01 - Blinking LED
 *
 * Heartbeat code baed on Heart Rate Badge code by 
 * Becky Stern for Adafruit Industries ... 
 * http://learn.adafruit.com/heart-rate-badge/program-it
 * ... who based hers on sample code from
 * http://learn.parallax.com/KickStart/28048
 *
 * Details on building the Heartbeat Hoodie at
 * http://johnkeefe.net/making-a-heartbeat-hoodie
 *
 * by John Keefe
 * john@johnkeefe.net
 *
 * February 2014
 *
 */

// set up an array of the pins the LEDs use
int light[] = {A3, A4, A5, 5, 6, 9, 10, A2};

// Set the heart monitor to run on pin 2
const int HR_RX = 11;
int oldSample, sample;
boolean monitor_detected = false;

// this code runs once
void setup() {
  
  for (int x = 0; x < 9; x++) {
    // set each LED pin as an output
    pinMode(light[x], OUTPUT); 
  }
  
  // Set the heart monitor pin to input
  pinMode (HR_RX, INPUT); 
  
  // light the bottom led just to show it's on
  // during setup
  digitalWrite(light[0], HIGH);
  
  // wait 5 seconds to see if there's a heart signal
  // loops 500 times, with a 10ms delay
  for (int x = 0; x <500; x++) {
    
    // if there's a heartbeat detected, set the 
    // monitor_detected variable to true and
    // bail out of the loop
    if (digitalRead(HR_RX)) {
      monitor_detected = true;
      break;
      
    // otherwise set the variable to false  
    } else {
      monitor_detected = false;
    }
    delay(10);
  }

}

// this code repeats forever
void loop() {
  
  // do this code if monitor_detected varialbe is true
  if (monitor_detected) {
  
    // Read the heard monitor. Will return a 1 if there's a beat
    sample = digitalRead(HR_RX); 
  
    // If the sample exits and it wasn't 1 on the last loop, new heart beat detected  
    if (sample && (oldSample != sample)) {
      
      // run the heartbeat function
      heartBeat();
  
    }
    oldSample = sample;  //Store last signal received 
  } else {
    
    // no monitor detected, so run the idle LED show
    idleBounce();
    
  }

}

// this is the heart beat function
void heartBeat (){
   
  /* light the hoodie in this pattern,
     radiating from the heart
      
      pin, order, light position on hoodie and in array
     
      A3 4 light 7
      A4 3 light 6
      A5 2 light 5
      5  1 light 4
      6  1 light 3
      7  2 light 2
      10 3 light 1
      A2 4 light 0
  
   */
   int delay_time = 25; // sets zip speed of LEDs
   digitalWrite(light[4], HIGH);
   digitalWrite(light[3], HIGH);
   delay(delay_time);
   digitalWrite(light[5], HIGH);
   digitalWrite(light[2], HIGH);
   digitalWrite(light[4], LOW);
   digitalWrite(light[3], LOW);
   delay(delay_time);
   digitalWrite(light[6], HIGH);
   digitalWrite(light[1], HIGH);
   digitalWrite(light[5], LOW);
   digitalWrite(light[2], LOW);
   delay(delay_time);
   digitalWrite(light[7], HIGH);
   digitalWrite(light[0], HIGH);
   digitalWrite(light[6], LOW);
   digitalWrite(light[1], LOW);
   delay(delay_time);
   digitalWrite(light[7], LOW);
   digitalWrite(light[0], LOW);  
   
}

// this gets called if there's no heart beat signal
// (so default if the monitor is not in use)
void idleBounce () {

     // spring the LED's into action!
   for (int y = 0; y < 8; y++) {
       digitalWrite(light[y], HIGH); // turns LEDs on
       delay(100);             // waits for 100 milliseconds
   }
  
   // turn them all off in reverse order
   for (int z = 0; z < 8; z++) {
      digitalWrite(light[7-z], LOW); // turns LED off
      delay(100);             // waits for 1/10 second
   }

}