Ryan Williams / Mbed 2 deprecated HACKGT_copy

hack gt final code

Dependencies:   4DGL-uLCD-SE BMP085 PinDetect SDFileSystem mbed wave_player

Heart.cpp@14:23390a020d1c, 2016-09-28 (annotated)

Committer:
otis22894
Date:
Wed Sep 28 00:16:16 2016 +0000
Revision:
14:23390a020d1c
Parent:
8:0620e2461b3a 
initial commit;

Who changed what in which revision?

UserRevisionLine numberNew contents of line
otis22894 8:0620e2461b3a 1 #include "Heart.h"
otis22894 8:0620e2461b3a 2 #include "mbed.h"
otis22894 8:0620e2461b3a 3
otis22894 8:0620e2461b3a 4 volatile int rate[10]; // array to hold last ten IBI values
otis22894 8:0620e2461b3a 5 volatile unsigned long sampleCounter = 0; // used to determine pulse timing
otis22894 8:0620e2461b3a 6 volatile unsigned long lastBeatTime = 0; // used to find IBI
otis22894 8:0620e2461b3a 7 volatile int P =512; // used to find peak in pulse wave, seeded
otis22894 8:0620e2461b3a 8 volatile int T = 512; // used to find trough in pulse wave, seeded
otis22894 8:0620e2461b3a 9 volatile int thresh = 512; // used to find instant moment of heart beat, seeded
otis22894 8:0620e2461b3a 10 volatile int amp = 100; // used to hold amplitude of pulse waveform, seeded
otis22894 8:0620e2461b3a 11 volatile bool firstBeat = true; // used to seed rate array so we startup with reasonable BPM
otis22894 8:0620e2461b3a 12 volatile bool secondBeat = false; // used to seed rate array so we startup with reasonable BPM
otis22894 8:0620e2461b3a 13 volatile int BPM; // used to hold the pulse rate
otis22894 8:0620e2461b3a 14 volatile int Signal; // holds the incoming raw data
otis22894 8:0620e2461b3a 15 volatile int IBI = 600; // holds the time between beats, must be seeded!
otis22894 8:0620e2461b3a 16 volatile bool Pulse = false; // true when pulse wave is high, false when it's low
otis22894 8:0620e2461b3a 17 volatile bool QS = false; // becomes true when Arduoino finds a beat.
otis22894 8:0620e2461b3a 18 volatile bool isBeating = false;
otis22894 8:0620e2461b3a 19 volatile int beatCount = 0;
otis22894 8:0620e2461b3a 20 volatile int PulseLength = 0;
otis22894 8:0620e2461b3a 21
otis22894 14:23390a020d1c 22 AnalogIn ain(p16);
otis22894 8:0620e2461b3a 23 DigitalOut myLED(LED1);
otis22894 8:0620e2461b3a 24 Ticker pulseReader;
otis22894 8:0620e2461b3a 25
otis22894 8:0620e2461b3a 26 Heart :: Heart() {
otis22894 8:0620e2461b3a 27 }
otis22894 8:0620e2461b3a 28
otis22894 8:0620e2461b3a 29 void Heart :: startReading() {
otis22894 8:0620e2461b3a 30 pulseReader.attach(this, &Heart::sample, .002f);
otis22894 8:0620e2461b3a 31 }
otis22894 8:0620e2461b3a 32
otis22894 8:0620e2461b3a 33 void Heart :: stopReading() {
otis22894 8:0620e2461b3a 34 pulseReader.detach();
otis22894 8:0620e2461b3a 35 __enable_irq();
otis22894 8:0620e2461b3a 36 }
otis22894 8:0620e2461b3a 37
otis22894 8:0620e2461b3a 38 void Heart :: reset() {
otis22894 8:0620e2461b3a 39 sampleCounter = 0; // used to determine pulse timing
otis22894 8:0620e2461b3a 40 lastBeatTime = 0; // used to find IBI
otis22894 8:0620e2461b3a 41 P =512; // used to find peak in pulse wave, seeded
otis22894 8:0620e2461b3a 42 T = 512; // used to find trough in pulse wave, seeded
otis22894 8:0620e2461b3a 43 thresh = 512; // used to find instant moment of heart beat, seeded
otis22894 8:0620e2461b3a 44 amp = 100; // used to hold amplitude of pulse waveform, seeded
otis22894 8:0620e2461b3a 45 firstBeat = true; // used to seed rate array so we startup with reasonable BPM
otis22894 8:0620e2461b3a 46 secondBeat = false; // used to seed rate array so we startup with reasonable BPM
otis22894 8:0620e2461b3a 47 IBI = 600; // holds the time between beats, must be seeded!
otis22894 8:0620e2461b3a 48 Pulse = false; // true when pulse wave is high, false when it's low
otis22894 8:0620e2461b3a 49 QS = false; // becomes true when Arduoino finds a beat.
otis22894 8:0620e2461b3a 50 isBeating = false;
otis22894 8:0620e2461b3a 51 beatCount = 0;
otis22894 8:0620e2461b3a 52 PulseLength = 0;
otis22894 8:0620e2461b3a 53 }
otis22894 8:0620e2461b3a 54
otis22894 8:0620e2461b3a 55 bool Heart :: beatDetected() {
otis22894 8:0620e2461b3a 56 return isBeating;
otis22894 8:0620e2461b3a 57 }
otis22894 8:0620e2461b3a 58
otis22894 8:0620e2461b3a 59 int Heart :: beatsCounted() {
otis22894 8:0620e2461b3a 60 return beatCount;
otis22894 8:0620e2461b3a 61 }
otis22894 8:0620e2461b3a 62
otis22894 8:0620e2461b3a 63 // THIS IS THE TIMER 2 INTERRUPT SERVICE ROUTINE.
otis22894 8:0620e2461b3a 64 // Timer 2 makes sure that we take a reading every 2 miliseconds
otis22894 8:0620e2461b3a 65 void Heart :: sample() { // triggered when Timer2 counts to 124
otis22894 8:0620e2461b3a 66 __disable_irq();
otis22894 8:0620e2461b3a 67 float readVal = ain; // disable interrupts while we do this
otis22894 8:0620e2461b3a 68 Signal = ain * 1024; // read the Pulse Sensor
otis22894 8:0620e2461b3a 69 sampleCounter += 2; // keep track of the time in mS with this variable
otis22894 8:0620e2461b3a 70 int N = sampleCounter - lastBeatTime; // monitor the time since the last beat to avoid noise
otis22894 8:0620e2461b3a 71
otis22894 8:0620e2461b3a 72 // find the peak and trough of the pulse wave
otis22894 8:0620e2461b3a 73 if(Signal < thresh && N > (IBI/5)*3){ // avoid dichrotic noise by waiting 3/5 of last IBI
otis22894 8:0620e2461b3a 74 if (Signal < T){ // T is the trough
otis22894 8:0620e2461b3a 75 T = Signal; // keep track of lowest point in pulse wave
otis22894 8:0620e2461b3a 76 }
otis22894 8:0620e2461b3a 77 }
otis22894 8:0620e2461b3a 78
otis22894 8:0620e2461b3a 79 if(Signal > thresh && Signal > P){ // thresh condition helps avoid noise
otis22894 8:0620e2461b3a 80 P = Signal; // P is the peak
otis22894 8:0620e2461b3a 81 } // keep track of highest point in pulse wave
otis22894 8:0620e2461b3a 82
otis22894 8:0620e2461b3a 83 // NOW IT'S TIME TO LOOK FOR THE HEART BEAT
otis22894 8:0620e2461b3a 84 // signal surges up in value every time there is a pulse
otis22894 8:0620e2461b3a 85 if (N > 250){ // avoid high frequency noise
otis22894 8:0620e2461b3a 86 if ( (Signal > thresh) && (Pulse == false) && (N > (IBI/5)*3) ){
otis22894 8:0620e2461b3a 87 Pulse = true; // set the Pulse flag when we think there is a pulse
otis22894 8:0620e2461b3a 88 IBI = sampleCounter - lastBeatTime; // measure time between beats in mS
otis22894 8:0620e2461b3a 89 lastBeatTime = sampleCounter; // keep track of time for next pulse
otis22894 8:0620e2461b3a 90
otis22894 8:0620e2461b3a 91 if(secondBeat){ // if this is the second beat, if secondBeat == TRUE
otis22894 8:0620e2461b3a 92 secondBeat = false; // clear secondBeat flag
otis22894 8:0620e2461b3a 93 for(int i=0; i<=9; i++){ // seed the running total to get a realisitic BPM at startup
otis22894 8:0620e2461b3a 94 rate[i] = IBI;
otis22894 8:0620e2461b3a 95 }
otis22894 8:0620e2461b3a 96 }
otis22894 8:0620e2461b3a 97
otis22894 8:0620e2461b3a 98 if(firstBeat){ // if it's the first time we found a beat, if firstBeat == TRUE
otis22894 8:0620e2461b3a 99 firstBeat = false; // clear firstBeat flag
otis22894 8:0620e2461b3a 100 secondBeat = true; // set the second beat flag
otis22894 8:0620e2461b3a 101 __enable_irq(); // enable interrupts again
otis22894 8:0620e2461b3a 102 return; // IBI value is unreliable so discard it
otis22894 8:0620e2461b3a 103 }
otis22894 8:0620e2461b3a 104
otis22894 8:0620e2461b3a 105
otis22894 8:0620e2461b3a 106 // keep a running total of the last 10 IBI values
otis22894 8:0620e2461b3a 107 unsigned short runningTotal = 0; // clear the runningTotal variable
otis22894 8:0620e2461b3a 108
otis22894 8:0620e2461b3a 109 for(int i=0; i<=8; i++){ // shift data in the rate array
otis22894 8:0620e2461b3a 110 rate[i] = rate[i+1]; // and drop the oldest IBI value
otis22894 8:0620e2461b3a 111 runningTotal += rate[i]; // add up the 9 oldest IBI values
otis22894 8:0620e2461b3a 112 }
otis22894 8:0620e2461b3a 113
otis22894 8:0620e2461b3a 114 rate[9] = IBI; // add the latest IBI to the rate array
otis22894 8:0620e2461b3a 115 runningTotal += rate[9]; // add the latest IBI to runningTotal
otis22894 8:0620e2461b3a 116 runningTotal /= 10; // average the last 10 IBI values
otis22894 8:0620e2461b3a 117 BPM = 60000/runningTotal; // how many beats can fit into a minute? that's BPM!
otis22894 8:0620e2461b3a 118 QS = true; // set Quantified Self flag
otis22894 8:0620e2461b3a 119 // QS FLAG IS NOT CLEARED INSIDE THIS ISR
otis22894 8:0620e2461b3a 120 myLED = 1;
otis22894 8:0620e2461b3a 121 }
otis22894 8:0620e2461b3a 122 }
otis22894 8:0620e2461b3a 123
otis22894 8:0620e2461b3a 124 if(Pulse) {
otis22894 8:0620e2461b3a 125 PulseLength+=2;
otis22894 8:0620e2461b3a 126 if (Signal < thresh){ // when the values are going down, the beat is over
otis22894 8:0620e2461b3a 127 myLED = 0; // turn off pin 13 LED
otis22894 8:0620e2461b3a 128 Pulse = false; // reset the Pulse flag so we can do it again
otis22894 8:0620e2461b3a 129 amp = P - T; // get amplitude of the pulse wave
otis22894 8:0620e2461b3a 130 //if (PulseLength > 4 && amp > (T/2)) {
otis22894 8:0620e2461b3a 131 if (PulseLength > 4 && amp > (T/3)) {
otis22894 8:0620e2461b3a 132 isBeating = true;
otis22894 8:0620e2461b3a 133 beatCount++;
otis22894 8:0620e2461b3a 134 }
otis22894 8:0620e2461b3a 135 thresh = amp/2 + T; // set thresh at 50% of the amplitude
otis22894 8:0620e2461b3a 136 P = thresh; // reset these for next time
otis22894 8:0620e2461b3a 137 T = thresh;
otis22894 8:0620e2461b3a 138 PulseLength = 0;
otis22894 8:0620e2461b3a 139 }
otis22894 8:0620e2461b3a 140 }
otis22894 8:0620e2461b3a 141
otis22894 8:0620e2461b3a 142 if (N > 2500){ // if 2.5 seconds go by without a beat
otis22894 8:0620e2461b3a 143 thresh = 512; // set thresh default
otis22894 8:0620e2461b3a 144 P = 512; // set P default
otis22894 8:0620e2461b3a 145 T = 512; // set T default
otis22894 8:0620e2461b3a 146 lastBeatTime = sampleCounter; // bring the lastBeatTime up to date
otis22894 8:0620e2461b3a 147 firstBeat = true; // set these to avoid noise
otis22894 8:0620e2461b3a 148 secondBeat = false; // when we get the heartbeat back
otis22894 8:0620e2461b3a 149 isBeating = false;
otis22894 8:0620e2461b3a 150 }
otis22894 8:0620e2461b3a 151
otis22894 8:0620e2461b3a 152 __enable_irq(); // enable interrupts when youre done!
otis22894 8:0620e2461b3a 153 }