Fix bugs on Processing Script

Software/Heart_Rate_Display_Processing/Heart_Rate_Display/Heart_Rate_Display.pde

@@ -14,9 +14,9 @@ Resources:
 This program requires a Processing sketch to view the data in real time.
 
 Development environment specifics:
-	IDE: Arduino 1.0.5
-	Hardware Platform: Arduino Pro 3.3V/8MHz
-	AD8232 Heart Monitor Version: 1.0
+IDE: Arduino 1.0.5
+Hardware Platform: Arduino Pro 3.3V/8MHz
+AD8232 Heart Monitor Version: 1.0
 
 This code is beerware. If you see me (or any other SparkFun employee) at the
 local pub, and you've found our code helpful, please buy us a round!
@@ -26,110 +26,102 @@ Distributed as-is; no warranty is given.
 
 import processing.serial.*;
 
-Serial myPort;        // The serial port
-int xPos = 1;         // horizontal position of the graph
+Serial myPort; // The serial port
+int xPos_i = 1; // X increment
+int xPos = xPos_i;  // horizontal position of the graph
 float height_old = 0;
 float height_new = 0;
 float inByte = 0;
 int BPM = 0;
 int beat_old = 0;
-float[] beats = new float[500];  // Used to calculate average BPM
+int array_size = 10; // how many "beats" to store to calculate the average
+float[] beats = new float[array_size]; // Used to calculate average BPM
 int beatIndex;
-float threshold = 620.0;  //Threshold at which BPM calculation occurs
+float threshold = 620.0; // Threshold at which BPM calculation occurs
 boolean belowThreshold = true;
 PFont font;
 
-
-void setup () {
+void setup() {
   // set the window size:
-  size(1000, 400);        
-
+  size(1500, 400); // increased width a little
   // List all the available serial ports
   println(Serial.list());
   // Open whatever port is the one you're using.
-  myPort = new Serial(this, Serial.list()[2], 9600);
+  myPort = new Serial(this, Serial.list()[1], 9600);
   // don't generate a serialEvent() unless you get a newline character:
   myPort.bufferUntil('\n');
   // set inital background:
   background(0xff);
-  font = createFont("Ariel", 12, true);
+  font = createFont("Arial", 12, true);
 }
 
+void draw() {
+  // Map and draw the line for new data point
+  float mapByte = map(inByte, 0, 1023, 0, height);
+  height_new = height - mapByte;
+
+  // at the edge of the screen, go back to the beginning:
+  if (xPos >= width) {
+    xPos = xPos_i;
+    background(0xff);
+  } else {
+    // increment the horizontal position:
+    xPos = xPos + xPos_i;
+  }
 
-void draw () {
-     //Map and draw the line for new data point
-     inByte = map(inByte, 0, 1023, 0, height);
-     height_new = height - inByte; 
-     line(xPos - 1, height_old, xPos, height_new);
-     height_old = height_new;
-
-      // at the edge of the screen, go back to the beginning:
-      if (xPos >= width) {
-        xPos = 0;
-        background(0xff);
-      } 
-      else {
-        // increment the horizontal position:
-        xPos++;
-      }
-
-      // draw text for BPM periodically
-      if (millis() % 128 == 0){
-        fill(0xFF);
-        rect(0, 0, 200, 20);
-        fill(0x00);
-        text("BPM: " + inByte, 15, 10);
-      }
-}
+  line(xPos - xPos_i, height_old, xPos, height_new);
+  height_old = height_new;
 
+  // draw text for BPM periodically
+  if (millis() % 128 == 0) {
+    fill(0xFF);
+    rect(0, 0, 200, 20);
+    fill(0x00);
+    text("BPM: " + BPM, 15, 10);
+  }
+}
 
-void serialEvent (Serial myPort) 
-{
+void serialEvent(Serial myPort) {
   // get the ASCII string:
   String inString = myPort.readStringUntil('\n');
 
-  if (inString != null) 
-  {
+  if (inString != null) {
     // trim off any whitespace:
     inString = trim(inString);
 
     // If leads off detection is true notify with blue line
-    if (inString.equals("!")) 
-    { 
-      stroke(0, 0, 0xff); //Set stroke to blue ( R, G, B)
-      inByte = 512;  // middle of the ADC range (Flat Line)
+    if (inString.equals("!")) {
+      stroke(0, 0, 0xff); // Set stroke to blue ( R, G, B)
+      inByte = 512.0;     // middle of the ADC range (Flat Line)
     }
     // If the data is good let it through
-    else 
-    {
-      stroke(0xff, 0, 0); //Set stroke to red ( R, G, B)
-      inByte = float(inString); 
-
+    else {
+      stroke(0xff, 0, 0); // Set stroke to red ( R, G, B)
+      inByte = float(inString);
+
       // BPM calculation check
-      if (inByte > threshold && belowThreshold == true)
-      {
+      if (inByte > threshold && belowThreshold == true) {
         calculateBPM();
         belowThreshold = false;
-      }
-      else if(inByte < threshold)
-      {
+      } else if (inByte < threshold) {
         belowThreshold = true;
       }
     }
   }
 }
-  
-void calculateBPM () 
-{  
-  int beat_new = millis();    // get the current millisecond
-  int diff = beat_new - beat_old;    // find the time between the last two beats
-  float currentBPM = 60000 / diff;    // convert to beats per minute
-  beats[beatIndex] = currentBPM;  // store to array to convert the average
-  float total = 0.0;
-  for (int i = 0; i < 500; i++){
-    total += beats[i];
-  }
-  BPM = int(total / 500);
-  beat_old = beat_new;
-  beatIndex = (beatIndex + 1) % 500;  // cycle through the array instead of using FIFO queue
+
+void calculateBPM() {
+  int beat_new = millis();         // get the current millisecond
+  int diff = beat_new - beat_old;  // find the time between the last two beats
+  if(diff > 0) { // solves the bug when diff equals zero
+    float currentBPM = 60000 / diff; // convert to beats per minute
+    beats[beatIndex] = currentBPM;   // store to array to convert the average
+    float total = 0.0;
+    for (int i = 0; i < array_size; i++) {
+      total += beats[i];
+    }
+    BPM = int(total / array_size);
+    beat_old = beat_new;
+    beatIndex = (beatIndex + 1) % array_size; // cycle through the array instead of using FIFO queue
   }
+}