Projet_BMC / Mbed 2 deprecated HeartPulseModify

heart rate mesuarement

Dependencies:   mbed USBDevice

main.cpp@2:515e6791dfe2, 2020-01-24 (annotated)

Committer:
zmoutaou
Date:
Fri Jan 24 11:16:30 2020 +0000
Revision:
2:515e6791dfe2
Parent:
0:a78b08608d76 
Pulse sensor

Who changed what in which revision?

UserRevisionLine numberNew contents of line
asagin 0:a78b08608d76 1 #include "mbed.h"
zmoutaou 2:515e6791dfe2 2 #include "USBSerial.h"
zmoutaou 2:515e6791dfe2 3 #include "Adafruit_SSD1306.h"
zmoutaou 2:515e6791dfe2 4 #include <string>
zmoutaou 2:515e6791dfe2 5 #include <sstream>
zmoutaou 2:515e6791dfe2 6 #include <map>
asagin 0:a78b08608d76 7
zmoutaou 2:515e6791dfe2 8 AnalogIn pulseIn(A0);
zmoutaou 2:515e6791dfe2 9 using namespace std;
zmoutaou 2:515e6791dfe2 10 USBSerial pc;
zmoutaou 2:515e6791dfe2 11 I2C i2c(PB_9, PB_8);
zmoutaou 2:515e6791dfe2 12 Adafruit_SSD1306_I2c oled(i2c,PC_13);
zmoutaou 2:515e6791dfe2 13
zmoutaou 2:515e6791dfe2 14
zmoutaou 2:515e6791dfe2 15 AnalogIn pulsePin(A0); //This is signal input
asagin 0:a78b08608d76 16
zmoutaou 2:515e6791dfe2 17 // these variables are because they are used during the interrupt service routine!
zmoutaou 2:515e6791dfe2 18 int BPM; // used to hold the pulse rate
zmoutaou 2:515e6791dfe2 19 int Signal; // holds the incoming raw data
zmoutaou 2:515e6791dfe2 20 int IBI = 600; // holds the time between beats, the Inter-Beat Interval
zmoutaou 2:515e6791dfe2 21 bool Pulse = false; // true when pulse wave is high, false when it's low
zmoutaou 2:515e6791dfe2 22 bool QS = false; // becomes true when Arduoino finds a beat.
asagin 0:a78b08608d76 23
zmoutaou 2:515e6791dfe2 24 void heart_rate_test(void);
zmoutaou 2:515e6791dfe2 25 int rate[10]; // used to hold last ten IBI values
zmoutaou 2:515e6791dfe2 26 unsigned long sampleCounter = 0; // used to determine pulse timing
zmoutaou 2:515e6791dfe2 27 unsigned long lastBeatTime = 0; // used to find the inter beat interval
zmoutaou 2:515e6791dfe2 28 int P =512; // used to find peak in pulse wave
zmoutaou 2:515e6791dfe2 29 int T = 512; // used to find trough in pulse wave
zmoutaou 2:515e6791dfe2 30 int thresh = 512; // used to find instant moment of heart beat
zmoutaou 2:515e6791dfe2 31 int amp = 100; // used to hold amplitude of pulse waveform
zmoutaou 2:515e6791dfe2 32 bool firstBeat = true; // used to seed rate array so we startup with reasonable BPM
zmoutaou 2:515e6791dfe2 33 bool secondBeat = true; // used to seed rate array so we startup with reasonable BPM
asagin 0:a78b08608d76 34
zmoutaou 2:515e6791dfe2 35 Ticker time_up;
zmoutaou 2:515e6791dfe2 36 // Escreve o texto passado como parâmetro no display
zmoutaou 2:515e6791dfe2 37 void OLED_writeString(string str, int x, int y) {
zmoutaou 2:515e6791dfe2 38 oled.clearDisplay();
zmoutaou 2:515e6791dfe2 39 oled.setTextCursor(x, y);
zmoutaou 2:515e6791dfe2 40 oled.fillRect(x, y, 128, 8, 0);
zmoutaou 2:515e6791dfe2 41 }
zmoutaou 2:515e6791dfe2 42
asagin 0:a78b08608d76 43
zmoutaou 2:515e6791dfe2 44 void heart_rate_test()
zmoutaou 2:515e6791dfe2 45 {
zmoutaou 2:515e6791dfe2 46 Signal = pulsePin.read()*1024; // read the Pulse Sensor
zmoutaou 2:515e6791dfe2 47 sampleCounter += 2; // keep track of the time in mS with this variable
zmoutaou 2:515e6791dfe2 48 int N = sampleCounter - lastBeatTime; // monitor the time since the last beat to avoid nois // find the peak and trough of the pulse wave
zmoutaou 2:515e6791dfe2 49 if(Signal < thresh && N > (IBI/5)*3) { // avoid dichrotic noise by waiting 3/5 of last IBI
zmoutaou 2:515e6791dfe2 50 if (Signal < T) { // T is the trough
zmoutaou 2:515e6791dfe2 51 T = Signal; // keep track of lowest point in pulse wave
zmoutaou 2:515e6791dfe2 52 }
zmoutaou 2:515e6791dfe2 53 }
zmoutaou 2:515e6791dfe2 54
zmoutaou 2:515e6791dfe2 55 if(Signal > thresh && Signal > P) { // thresh condition helps avoid noise
zmoutaou 2:515e6791dfe2 56 P = Signal; // P is the peak
zmoutaou 2:515e6791dfe2 57 } // keep track of highest point in pulse wave
zmoutaou 2:515e6791dfe2 58
zmoutaou 2:515e6791dfe2 59 // NOW IT'S TIME TO LOOK FOR THE HEART BEAT
zmoutaou 2:515e6791dfe2 60 // signal surges up in value every time there is a pulse
zmoutaou 2:515e6791dfe2 61 if (N > 250) { // avoid high frequency noise
zmoutaou 2:515e6791dfe2 62 if ( (Signal > thresh) && (Pulse == false) && (N > (IBI/5)*3) ) {
zmoutaou 2:515e6791dfe2 63 Pulse = true; // set the Pulse flag when we think there is a pulse
zmoutaou 2:515e6791dfe2 64 //digitalWrite(blinkPin,HIGH); // turn on pin 13 LED
zmoutaou 2:515e6791dfe2 65 IBI = sampleCounter - lastBeatTime; // measure time between beats in mS
zmoutaou 2:515e6791dfe2 66 lastBeatTime = sampleCounter; // keep track of time for next pulse
zmoutaou 2:515e6791dfe2 67
zmoutaou 2:515e6791dfe2 68 if(firstBeat) { // if it's the first time we found a beat, if firstBeat == TRUE
zmoutaou 2:515e6791dfe2 69 firstBeat = false; // clear firstBeat flag
zmoutaou 2:515e6791dfe2 70 return; // IBI value is unreliable so discard it
zmoutaou 2:515e6791dfe2 71 }
zmoutaou 2:515e6791dfe2 72 if(secondBeat) { // if this is the second beat, if secondBeat == TRUE
zmoutaou 2:515e6791dfe2 73 secondBeat = false; // clear secondBeat flag
zmoutaou 2:515e6791dfe2 74 for(int i=0; i<=9; i++) { // seed the running total to get a realisitic BPM at startup
zmoutaou 2:515e6791dfe2 75 rate[i] = IBI;
zmoutaou 2:515e6791dfe2 76 }
zmoutaou 2:515e6791dfe2 77 }
zmoutaou 2:515e6791dfe2 78
zmoutaou 2:515e6791dfe2 79 // keep a running total of the last 10 IBI values
zmoutaou 2:515e6791dfe2 80 long runningTotal = 0; // clear the runningTotal variable
zmoutaou 2:515e6791dfe2 81
zmoutaou 2:515e6791dfe2 82 for(int i=0; i<=8; i++) { // shift data in the rate array
zmoutaou 2:515e6791dfe2 83 rate[i] = rate[i+1]; // and drop the oldest IBI value
zmoutaou 2:515e6791dfe2 84 runningTotal += rate[i]; // add up the 9 oldest IBI values
zmoutaou 2:515e6791dfe2 85 }
zmoutaou 2:515e6791dfe2 86
zmoutaou 2:515e6791dfe2 87 rate[9] = IBI; // add the latest IBI to the rate array
zmoutaou 2:515e6791dfe2 88 runningTotal += rate[9]; // add the latest IBI to runningTotal
zmoutaou 2:515e6791dfe2 89 runningTotal /= 10; // average the last 10 IBI values
zmoutaou 2:515e6791dfe2 90 BPM = 60000/runningTotal; // how many beats can fit into a minute? that's BPM!
zmoutaou 2:515e6791dfe2 91 QS = true;
zmoutaou 2:515e6791dfe2 92 string BPM_s= static_cast<ostringstream*>( &(ostringstream() << BPM) )->str();
zmoutaou 2:515e6791dfe2 93 OLED_writeString(BPM_s, 1, 1);
zmoutaou 2:515e6791dfe2 94 // QS FLAG IS NOT CLEARED INSIDE THIS ISR
zmoutaou 2:515e6791dfe2 95 }
zmoutaou 2:515e6791dfe2 96 }
zmoutaou 2:515e6791dfe2 97
zmoutaou 2:515e6791dfe2 98 if (Signal < thresh && Pulse == true) { // when the values are going down, the beat is over
zmoutaou 2:515e6791dfe2 99 Pulse = false; // reset the Pulse flag so we can do it again
zmoutaou 2:515e6791dfe2 100 amp = P - T; // get amplitude of the pulse wave
zmoutaou 2:515e6791dfe2 101 thresh = amp/2 + T; // set thresh at 50% of the amplitude
zmoutaou 2:515e6791dfe2 102 P = thresh; // reset these for next time
zmoutaou 2:515e6791dfe2 103 T = thresh;
zmoutaou 2:515e6791dfe2 104 }
zmoutaou 2:515e6791dfe2 105
zmoutaou 2:515e6791dfe2 106 if (N > 2500) { // if 2.5 seconds go by without a beat
zmoutaou 2:515e6791dfe2 107 thresh = 512; // set thresh default
zmoutaou 2:515e6791dfe2 108 P = 512; // set P default
zmoutaou 2:515e6791dfe2 109 T = 512; // set T default
zmoutaou 2:515e6791dfe2 110 lastBeatTime = sampleCounter; // bring the lastBeatTime up to date
zmoutaou 2:515e6791dfe2 111 firstBeat = true; // set these to avoid noise
zmoutaou 2:515e6791dfe2 112 secondBeat = true; // when we get the heartbeat back
zmoutaou 2:515e6791dfe2 113 }
asagin 0:a78b08608d76 114
zmoutaou 2:515e6791dfe2 115
asagin 0:a78b08608d76 116 }
asagin 0:a78b08608d76 117
asagin 0:a78b08608d76 118
zmoutaou 2:515e6791dfe2 119 int main()
zmoutaou 2:515e6791dfe2 120 {
zmoutaou 2:515e6791dfe2 121 time_up.attach(&heart_rate_test, 0.002);
zmoutaou 2:515e6791dfe2 122 oled.clearDisplay();
zmoutaou 2:515e6791dfe2 123 OLED_writeString("hello world", 1, 1);
zmoutaou 2:515e6791dfe2 124 while(true)
zmoutaou 2:515e6791dfe2 125 {
zmoutaou 2:515e6791dfe2 126 if (QS == true)
zmoutaou 2:515e6791dfe2 127 {
zmoutaou 2:515e6791dfe2 128
zmoutaou 2:515e6791dfe2 129 QS = false;
zmoutaou 2:515e6791dfe2 130 //pc.printf("%d \n ",BPM); // reset the Quantified Self flag for next time
zmoutaou 2:515e6791dfe2 131 }
zmoutaou 2:515e6791dfe2 132 wait_ms(20);
zmoutaou 2:515e6791dfe2 133 }
zmoutaou 2:515e6791dfe2 134 }
asagin 0:a78b08608d76 135
asagin 0:a78b08608d76 136
zmoutaou 2:515e6791dfe2 137
zmoutaou 2:515e6791dfe2 138