Revision 10:ad2548407023, committed 2015-10-28

Comitter:

maryannionascu

Date:

Wed Oct 28 17:55:39 2015 +0000

Parent:

9:b2a894f94cb7

Commit message:

Updated comments

Changed in this revision

diff -r b2a894f94cb7 -r ad2548407023 main.cpp
--- a/main.cpp	Thu Oct 22 20:24:19 2015 +0000
+++ b/main.cpp	Wed Oct 28 17:55:39 2015 +0000
@@ -17,7 +17,8 @@
 volatile unsigned long lastBeatTime = 0;    //time of last beat 
 volatile float peak = 25;    //peak of heartbeat wave; initilized to 20 to avoid noise at startup
 volatile float trough = 15;  //trough of heartbeat wave
-volatile float thresh = 10;  // used to reduce noice
+volatile float lowerThresh = 10;  // used to reduce noice; change these values based on amount of light in room
+volatile float upperThresh = 30;  // used to reduce noice; change these values based on amount of light in room
 volatile float amp = 5; // amplitude of heartbeat wave
 volatile bool firstBeat = true; //keeps track of first beat found
 volatile bool beatFound = false;    //true when a beat is found, false in between beats
@@ -28,19 +29,19 @@
     beat = photoresistor * 100;   // read the analog data from the photoresistor and multiply by 100 (amplifies small values)          
     currIBI = t.read() - lastBeatTime;  
     // avoid noise by waiting 3/5 of last IBI     
-    if((beat < thresh) && (currIBI > (lastIBI*3)/5)){       
+    if((beat < lowerThresh) && (currIBI > (lastIBI*3)/5)){       
         if (beat < trough){                       
             trough = beat;                         
         }
     }
-    if((beat > thresh) && (beat > peak)){          
+    if((beat > upperThresh) && (beat > peak)){          
         peak = beat;                            
     }                                      
     // photoresistor signal surges when there is a heartbeat
-    if ((currIBI > 0.25) && (beat > thresh) && (beat > 30) && (beatFound == false)){ 
+    if ((currIBI > 0.25) && (beat > upperThresh) && (beatFound == false)){ 
         beatFound = true;  
         beatCount++;
-        thresh = beat - 0.7; //adjust threshold to account for any change in lighting and avoid noise                          
+        lowerThresh = beat - 0.7; //adjust threshold to account for any change in lighting and avoid noise                          
         lastIBI = t.read() - lastBeatTime;  
         lastBeatTime = t.read();                
         //if this is  the first beat found, fill pastIBI values with this value until more beats are found
@@ -65,23 +66,13 @@
         }                                             
     }
     //when the signal is less than the threshold, the beat is over 
-    if (((beat < thresh) && beatFound) || (currIBI > 2)){     
+    if (((beat < lowerThresh) && beatFound) || (currIBI > 2)){     
         beatFound = false;                     // reset the beatFound flag to find the next beat
         amp = peak - trough;                   // calculate amplitude of heartbeat wave
-        thresh = amp/2 + trough;               // set threshold to 50% of the amplitude
-        peak = thresh;                         
-        trough = thresh;
+        upperThresh = amp/2 + trough;               // set upper threshold to 50% of the amplitude
+        peak = upperThresh;                         
+        trough = lowerThresh;
     }
-    /*
-    //if 3 seconds pass since the last beat, reset all variables to default values
-    if (currIBI > 3){                       
-        thresh = 10;                         
-        peak = 10;                             
-        trough = 10;                        
-        lastBeatTime = t.read();              
-        firstBeat = true;                                    
-    }
-    */
     __enable_irq();   //enable interrupts
 } 
 
@@ -119,23 +110,8 @@
         else{
             uLCD.locate(1,2);
             uLCD.printf("\nCalculating...\n");
-            //uLCD.printf("%2F\n", (float) photoresistor*100);
-            //uLCD.printf("beatCount: %2F\n", (float) beatCount);
-            //uLCD.printf("currIBI: %2F\n", (float) currIBI);
             wait(.1);
             uLCD.cls();
-            /*
-            uLCD.printf("%2F\n", (float) photoresistor*100);
-            //uLCD.printf("BPMfound: %2F\n", (float) BPMfound);
-            uLCD.printf("beatFound: %2F\n", (float) beatFound);
-            uLCD.printf("beatCount: %2F\n", (float) beatCount);
-            //uLCD.printf("firstBeat: %2F\n", (float) firstBeat);
-            uLCD.printf("thresh: %2F\n", (float) thresh);
-            //uLCD.printf("sumIBI: %2F\n", (float) sumIBI);
-            //uLCD.printf("time: %2F\n", (float) t.read());
-            wait(.1);
-            uLCD.cls();
-            */
         }
     }
 }