#include <SoftwareSerial.h>
SoftwareSerial xbee(2,3);
//
int led11=6,led12=4;
int motor=9,bmotor=7,buzzer=8;
//
volatile int BPM; // 심박수 저장
volatile int Signal; // 심장박동센서에서 측정되는 값 저장
volatile int IBI=600; // 심박수 측정 시 사용되는 시간 변수(심장이 몇초마다 뛰는지 측정)
volatile boolean Pulse=false; // 유저의 심박수가 측정되면 True,아무것도 측정되지 않으면 False
//
void setup(){
Serial.begin(9600); xbee.begin(9600);
pinMode(motor,OUTPUT); pinMode(bmotor,OUTPUT); pinMode(buzzer,OUTPUT);
pinMode( led2,OUTPUT); pinMode(led1,OUTPUT);
interruptSetup(); // 센서의 신호를 2ms마다 읽어 심박수로 변환하는 함수
}
//
void loop(){
if(xbee.available()){
char data=xbee.read();
if(data=='a'){ digitalWrite(motor, LOW); digitalWrite(bmotor, LOW); digitalWrite(buzzer, LOW); }
if(data=='b'){ digitalWrite(motor,HIGH); digitalWrite(bmotor,HIGH); digitalWrite(buzzer,HIGH); }
}
// BPM -> 심박수
Serial.print("*** Heart-Beat Happened *** BPM: "); Serial.println(BPM);
if(BPM<80){ digitalWrite(led12,HIGH); digitalWrite(led11,LOW); }
else { digitalWrite(led11,HIGH); digitalWrite(led12,LOW); }
delay(1000);
}
아두이노 소스이며
밑에는 인터럽트 소스입니다.
volatile int rate[10]; // array to hold last ten IBI values
volatile unsigned long sampleCounter = 0; // used to determine pulse timing
volatile unsigned long lastBeatTime = 0; // used to find IBI
volatile int P =512; // used to find peak in pulse wave, seeded
volatile int T = 512; // used to find trough in pulse wave, seeded
volatile int thresh = 525; // used to find instant moment of heart beat, seeded
volatile int amp = 100; // used to hold amplitude of pulse waveform, seeded
volatile boolean firstBeat = true; // used to seed rate array so we startup with reasonable BPM
volatile boolean secondBeat = false; // used to seed rate array so we startup with reasonable BPM
void interruptSetup(){
// Initializes Timer2 to throw an interrupt every 2mS.
TCCR2A = 0x02; // DISABLE PWM ON DIGITAL PINS 3 AND 11, AND GO INTO CTC MODE
TCCR2B = 0x06; // DON'T FORCE COMPARE, 256 PRESCALER
OCR2A = 0X7C; // SET THE TOP OF THE COUNT TO 124 FOR 500Hz SAMPLE RATE
TIMSK2 = 0x02; // ENABLE INTERRUPT ON MATCH BETWEEN TIMER2 AND OCR2A
sei(); // MAKE SURE GLOBAL INTERRUPTS ARE ENABLED
}
// THIS IS THE TIMER 2 INTERRUPT SERVICE ROUTINE.
// Timer 2 makes sure that we take a reading every 2 miliseconds
ISR(TIMER2_COMPA_vect){ // triggered when Timer2 counts to 124
cli(); // disable interrupts while we do this
Signal = analogRead(0); // read the Pulse Sensor
sampleCounter += 2; // keep track of the time in mS with this variable
int N = sampleCounter - lastBeatTime; // monitor the time since the last beat to avoid noise
// find the peak and trough of the pulse wave
if(Signal < thresh && N > (IBI/5)*3){ // avoid dichrotic noise by waiting 3/5 of last IBI
if (Signal < T){ // T is the trough
T = Signal; // keep track of lowest point in pulse wave
}
}
if(Signal > thresh && Signal > P){ // thresh condition helps avoid noise
P = Signal; // P is the peak
} // keep track of highest point in pulse wave
// NOW IT'S TIME TO LOOK FOR THE HEART BEAT
// signal surges up in value every time there is a pulse
if (N > 250){ // avoid high frequency noise
if ( (Signal > thresh) && (Pulse == false) && (N > (IBI/5)*3) ) {
Pulse = true; // set the Pulse flag when we think there is a pulse
IBI = sampleCounter - lastBeatTime; // measure time between beats in mS
lastBeatTime = sampleCounter; // keep track of time for next pulse
if(secondBeat){ // if this is the second beat, if secondBeat == TRUE
secondBeat = false; // clear secondBeat flag
for(int i=0; i<=9; i++){ // seed the running total to get a realisitic BPM at startup
rate[i] = IBI;
}
}
if(firstBeat){ // if it's the first time we found a beat, if firstBeat == TRUE
firstBeat = false; // clear firstBeat flag
secondBeat = true; // set the second beat flag
sei(); // enable interrupts again
return; // IBI value is unreliable so discard it
}
// keep a running total of the last 10 IBI values
word runningTotal = 0; // clear the runningTotal variable
for(int i=0; i<=8; i++){ // shift data in the rate array
rate[i] = rate[i+1]; // and drop the oldest IBI value
runningTotal += rate[i]; // add up the 9 oldest IBI values
}
rate[9] = IBI; // add the latest IBI to the rate array
runningTotal += rate[9]; // add the latest IBI to runningTotal
runningTotal /= 10; // average the last 10 IBI values
BPM = 60000/runningTotal; // how many beats can fit into a minute? that's BPM!
// QS FLAG IS NOT CLEARED INSIDE THIS ISR
}
}
if (Signal < thresh && Pulse == true){ // when the values are going down, the beat is over
// digitalWrite(blinkPin,LOW); // turn off pin 13 LED
Pulse = false; // reset the Pulse flag so we can do it again
amp = P - T; // get amplitude of the pulse wave
thresh = amp/2 + T; // set thresh at 50% of the amplitude
P = thresh; // reset these for next time
T = thresh;
}
if (N > 2500){ // if 2.5 seconds go by without a beat
thresh = 512; // set thresh default
P = 512; // set P default
T = 512; // set T default
lastBeatTime = sampleCounter; // bring the lastBeatTime up to date
firstBeat = true; // set these to avoid noise
secondBeat = false; // when we get the heartbeat back
}
sei(); // enable interrupts when youre done!
}
