Diff: windSensor.cpp

Revision:

0:397523d4133e

Child:

1:86d9b36d9132

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/windSensor.cpp	Thu Dec 01 00:42:08 2016 +0000
@@ -0,0 +1,137 @@
+#include "windSensor.h"
+
+windSensor :: windSensor(PinName p, NeoStrip *_strip)
+    : sensor(p), strip(_strip)
+{
+    thresh = sensor.read()*1.4;
+    isBreathing = false;
+    breathCount = 0;
+    strip->setBrightness(0.1);
+}
+
+void windSensor::startReading()
+{
+    breathReader.attach(this, &windSensor::sample, .002f);
+    //volatile float a = sensor;
+    //printf("\nwindsensor reads: %f", a);
+    //printf("\nthresh is: %f", thresh);
+}
+
+void windSensor::stopReading()
+{
+    breathReader.detach();
+    __enable_irq();
+}
+
+void windSensor::reset()
+{
+    //thresh = sensor*1.2; //set thresh to an appropraite percent above the baseline reading
+    //Breath = false;     // true victims breath crosses thresh
+    isBreathing = false; //true if we get 3 'Breaths' in the calling programs time window-->means victim is breathing
+    breathCount = 0;
+}
+
+//call this member function to see if victim is breathing
+bool windSensor::breathDetected()
+{
+    return isBreathing; //only return positive if we get the critical number of Breaths in the given time window
+}
+
+
+// THIS IS THE TIMER 2 INTERRUPT SERVICE ROUTINE.
+// Timer 2 makes sure that we take a reading every 2 miliseconds
+void windSensor:: sample()                           // triggered when Timer2 counts to 124
+{
+    __disable_irq();
+    float readVal = sensor.read();                          // sample
+
+
+    //check to see if victim is breathing at all above natural variation in sensor noise
+    if(readVal >= thresh) {
+        breathCount++;                         //increment global counter
+    }
+    if(breathCount >= 3) { //should set this higher if want more certainty in victim breathing
+        isBreathing = true;
+    }
+    __enable_irq();                               // enable interrupts again
+    //return;
+}
+
+template<typename T>
+void pop_front(std::vector<T>& vec)
+{
+    //assert(!vec.empty());
+    vec.erase(vec.begin());
+}
+
+float windSensor::give_breath(void)
+{
+    strip->initialize();
+    c.clear();
+    t.reset();
+    q.reset();
+    //float a = 0.0;
+    float d = 0.0; //return time for fractional breathes
+    float e = 0.0;
+    int i;
+    float thresh;
+    /*for(i = 0; i<20; i++) {
+        float val = sensor.read();
+        a = a + val;
+        //printf("%12.5f\n",val);
+    }
+    a = a/20.0; //get first baseline reading
+    //thresh = a*3.0; //theshold to start breathe timer (ideal multiplier is between 2-3)*/
+    thresh = 0.63;
+    //printf("thresh:%f\n",thresh);
+    t.start();
+    while(1) {
+        if(t.read() <= 3.0) {
+            wait(0.1); //necessary to give sensor time to be polled
+            float val = sensor.read();
+            //printf("%15.5f\n",val);
+            if(val > thresh) {
+                //printf("Made it here\n");
+                q.start();
+                for(i = 0; i<10; i++) {
+                    c.push_back(val);
+                }
+                for(i=0; i<10; i++) {
+                    e = e + c[i];
+                }
+                e = e/10.0; //provides slope of 10 most recent samples
+                float oldTimerVal = 0;
+                float timerVal = q.read();
+                while( (e > thresh) && (timerVal < 1.0)) {
+
+                    pop_front(c);//remove the oldest element
+                    c.push_back(sensor.read());
+                    for(i=0; i<10; i++) {
+                        e = e + c[i];
+                    }
+                    e = e/10.0; //provides slope of 10 most recent samples
+                    timerVal = q.read();
+                    if(timerVal >= oldTimerVal + 0.25){
+                        strip->progress(timerVal);
+                        oldTimerVal = timerVal;
+                    }
+                }
+                d = q.read();
+                if(q.read() > 1.0) { //breathe was greater than thresh and lasted more than 1 sec
+                    t.stop(); q.stop();
+                    strip->progress(1);
+                    return 1.0; //full breath
+                } else {
+                    t.stop(); q.stop();
+                    return d; //partial breath
+                }
+            }
+        } else {
+            t.stop(); q.stop();
+            return 0.0; //no breath in 3 seconds
+        }
+    }
+
+}
+
+