Diff: main.cpp

Revision:

0:901c98b3591a

Child:

1:b7f42e8e04fc

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/main.cpp	Mon Apr 13 22:54:38 2015 +0000
@@ -0,0 +1,96 @@
+#include "mbed.h"
+#include "math.h"
+Ticker flipper;
+Ticker flipper2;
+DigitalOut led2(LED2);
+AnalogIn sensor(p20);
+AnalogIn sensor_visible(p19);
+AnalogIn sensor_invisible(p18); 
+
+//680 nm
+#define visible 68 
+//940 nm
+#define invisible 94
+
+ 
+
+float data =0; 
+float previous_data =0;
+int count1=-1;
+int count2=-1;
+float max1 =0.0;
+float max2 =0.0;
+int running_count=0;  
+bool foundMax = false;
+#define difference 0.05 
+#define count_period 0.1
+void flip() {
+    led2 = !led2;
+    previous_data = data; 
+   // printf("Data = %f\t",data);
+    data = sensor.read() * 3.3;
+    running_count++;  
+   // printf("data = %f\n",data);
+    if (data - previous_data > 0){
+        //increasing 
+        printf("Increasing \n");
+        //do nothing
+    }     
+    else if(data - previous_data < 0 && !foundMax){
+        //check if foundMax 
+        printf("found max \n");        
+        foundMax = true;
+        count1 = running_count; 
+        max1 = data;    
+    }
+    else{
+        printf("Decrease\n");    
+    }
+    if(max1-data < difference && data-previous_data >0 && foundMax){
+        //found second max; 
+        printf("found second max \n");
+        count2 = running_count;     
+        float period = (count2 - count1)* count_period; 
+        
+        float BPM = (1/period) * 60;
+        printf("BPM = %f",BPM);
+        exit(1);
+        //reset 
+        count1 = 0;
+        count2 =0; 
+        foundMax = false; 
+        max1 =0;
+        running_count =0; 
+    }
+    
+}
+
+void findOxygenSaturation(){
+    
+    float v = log10f(sensor_visible.read()*3.3) * visible;
+    float iv = log10f(sensor_invisible.read()*3.3) * invisible; 
+    printf("visible = %f\n",v);
+    printf("invisible = %f\n",iv);
+    float ratio = v/iv;
+    printf("ratio = %f\n",ratio);
+    float spo = -0.3393 * ratio + 1.1595 ;
+    printf("spo = %f\n",spo);
+}
+
+
+int main() {
+    led2 = 1;
+    //comment out the below line to test heart rate 
+    //the heart rate test subroutine, once it find the heart rate, it will terminate the program.
+    //so make sure you reset the MBED
+    //flipper.attach(&flip, count_period); // the address of the function to be attached (flip) and the interval (1 seconds)    
+    
+    
+    //read OxygenSaturation Every two second. 
+    //use pin 19 for visible light input
+    //use pin 18 for invisible light input
+    flipper2.attach(&findOxygenSaturation,2.0);
+    while(1) {
+    
+    }
+}
\ No newline at end of file