脉冲传感器+ arduino mkr1000来计算BPM

问题描述：

tldr;使用脉冲传感器和mkr1000计算BPM的简单/合理的方法（对于初学者）是什么？我不希望任何图表或处理草图，但只是打印BPM值脉冲传感器+ arduino mkr1000来计算BPM

请多多包涵，我在这一个新手，我已经尽我所能理解这一点，并解决这个问题，但不成功。

我正在使用带有Arduino mkr1000的脉冲传感器（SEN-11574）来计算BPM并将其打印在串行监视器中。我能够使用他们的首发代码

// Variables 
int PulseSensorPurplePin = 0;  // Pulse Sensor PURPLE WIRE connected to ANALOG PIN 0 
int LED13 = 13; // The on-board Arduion LED 


int Signal;    // holds the incoming raw data. Signal value can range from 0-1024 
int Threshold = 550;   // Determine which Signal to "count as a beat", and which to ingore. 


// The SetUp Function: 
void setup() { 
    pinMode(LED13,OUTPUT);   // pin that will blink to your heartbeat! 
    Serial.begin(9600);   // Set's up Serial Communication at certain speed. 

} 

// The Main Loop Function 
void loop() { 

    Signal = analogRead(PulseSensorPurplePin); // Read the PulseSensor's value. 
               // Assign this value to the "Signal" variable. 

    Serial.println(Signal);     // Send the Signal value to Serial Plotter. 


    if(Signal > Threshold){       // If the signal is above "550", then "turn-on" Arduino's on-Board LED. 
    digitalWrite(LED13,HIGH);   
    } else { 
    digitalWrite(LED13,LOW);    // Else, the sigal must be below "550", so "turn-off" this LED. 
    } 


delay(10); 
}

然而，真正的问题是，我无法利用现有的示例代码来计算BPM获得原始读数据我了解on their website here ，中断定时器功能在中断.ino文件与mkr1000不兼容。附上这段代码供您参考。

// 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(pulsePin);    // 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 
     digitalWrite(blinkPin,HIGH);    // turn on pin 13 LED 
     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 = true;        // set Quantified Self flag 
     // 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 = 530;       // 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! 
}// end isr

在中断备注文件，他们提到另一个变通对于不是与此代码兼容的处理器，但即使按照说明资讯小时后，该代码没有与计时器错误工作，再次中断功能。

接下来，我使用了this guide，但是它又不起作用，只是打印不断变化的原始信号值（S1023）。代码附加（2个选项卡）：

/* Pulse Sensor Amped 1.4 by Joel Murphy and Yury Gitman http://www.pulsesensor.com 
Adapted by sdizdarevic 
---------------------- Notes ---------------------- ---------------------- 
This code: 
1) Blinks an LED to User's Live Heartbeat PIN 6 
2) Fades an LED to User's Live HeartBeat 
3) Determines BPM 
4) Prints All of the Above to Serial 
Read Me: 
https://github.com/WorldFamousElectronics/PulseSensor_Amped_Arduino/blob/master/README.md 
----------------------  ---------------------- ---------------------- 
*/ 


// Variables 
int pulsePin = 0;     // Pulse Sensor purple wire connected to analog pin 0 
int blinkPin = 6;    // pin to blink led at each beat 
//int fadePin = 5;     // pin to do fancy classy fading blink at each beat 
//int fadeRate = 0;     // used to fade LED on with PWM on fadePin 

// Volatile Variables, used in the interrupt service routine! 
volatile int BPM;     // int that holds raw Analog in 0. updated every 2mS 
volatile int Signal;    // holds the incoming raw data 
volatile int IBI = 600;    // int that holds the time interval between beats! Must be seeded! 
volatile boolean Pulse = false;  // "True" when User's live heartbeat is detected. "False" when not a "live beat". 
volatile boolean QS = false;  // becomes true when Arduoino finds a beat. 



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 




// Regards Serial OutPut -- Set This Up to your needs 
static boolean serialVisual = false; // Set to 'false' by Default. Re-set to 'true' to see Arduino Serial Monitor ASCII Visual Pulse 


void setup(){ 
    pinMode(blinkPin,OUTPUT);   // pin that will blink to your heartbeat! 
    //pinMode(fadePin,OUTPUT);   // pin that will fade to your heartbeat! 
    Serial.begin(115200);    // we agree to talk fast! 
    //interruptSetup();     // sets up to read Pulse Sensor signal every 2mS 
    // IF YOU ARE POWERING The Pulse Sensor AT VOLTAGE LESS THAN THE BOARD VOLTAGE, 
    // UN-COMMENT THE NEXT LINE AND APPLY THAT VOLTAGE TO THE A-REF PIN 
// analogReference(EXTERNAL); 
} 


// Where the Magic Happens 
void loop(){ 

// 
// 
Signal = analogRead(pulsePin);    // 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 
     digitalWrite(blinkPin,HIGH);    // turn on pin 13 LED 
     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 

     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 = true;        // set Quantified Self flag 
     // 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 
    } 





    serialOutput() ;  

    if (QS == true){  // A Heartbeat Was Found 
         // BPM and IBI have been Determined 
         // Quantified Self "QS" true when arduino finds a heartbeat 
     // fadeRate = 255;   // Makes the LED Fade Effect Happen 
           // Set 'fadeRate' Variable to 255 to fade LED with pulse 
     serialOutputWhenBeatHappens(); // A Beat Happened, Output that to serial.  
     QS = false;      // reset the Quantified Self flag for next time  
    } 

// ledFadeToBeat();      // Makes the LED Fade Effect Happen 
    delay(20);        // take a break 
} 





/*void ledFadeToBeat(){ 
    fadeRate -= 15;       // set LED fade value 
    fadeRate = constrain(fadeRate,0,255); // keep LED fade value from going into negative numbers! 
    //analogWrite(fadePin,fadeRate);   // fade LED 
    } 
*/

SerialHandling文件：

////////// 
///////// All Serial Handling Code, 
///////// It's Changeable with the 'serialVisual' variable 
///////// Set it to 'true' or 'false' when it's declared at start of code. 
///////// 

void serialOutput(){ // Decide How To Output Serial. 
if (serialVisual == true){ 
    arduinoSerialMonitorVisual('-', Signal); // goes to function that makes Serial Monitor Visualizer 
} else{ 
     sendDataToSerial('S', Signal);  // goes to sendDataToSerial function 
}   
} 


// Decides How To OutPut BPM and IBI Data 
void serialOutputWhenBeatHappens(){  
if (serialVisual == true){   // Code to Make the Serial Monitor Visualizer Work 
    Serial.print("*** Heart-Beat Happened *** "); //ASCII Art Madness 
    Serial.print("BPM: "); 
    Serial.print(BPM); 
    Serial.print(" "); 
} else{ 
     sendDataToSerial('B',BPM); // send heart rate with a 'B' prefix 
     sendDataToSerial('Q',IBI); // send time between beats with a 'Q' prefix 
} 
} 



// Sends Data to Pulse Sensor Processing App, Native Mac App, or Third-party Serial Readers. 
void sendDataToSerial(char symbol, int data){ 
    Serial.print(symbol); 

    Serial.println(data);     
    } 


// Code to Make the Serial Monitor Visualizer Work 
void arduinoSerialMonitorVisual(char symbol, int data){  
    const int sensorMin = 0;  // sensor minimum, discovered through experiment 
const int sensorMax = 1024; // sensor maximum, discovered through experiment 

    int sensorReading = data; 
    // map the sensor range to a range of 12 options: 
    int range = map(sensorReading, sensorMin, sensorMax, 0, 11); 

    // do something different depending on the 
    // range value: 
    switch (range) { 
    case 0:  
    Serial.println("");  /////ASCII Art Madness 
    break; 
    case 1: 
    Serial.println("---"); 
    break; 
    case 2:  
    Serial.println("------"); 
    break; 
    case 3:  
    Serial.println("---------"); 
    break; 
    case 4: 
    Serial.println("------------"); 
    break; 
    case 5: 
    Serial.println("--------------|-"); 
    break; 
    case 6: 
    Serial.println("--------------|---"); 
    break; 
    case 7: 
    Serial.println("--------------|-------"); 
    break; 
    case 8: 
    Serial.println("--------------|----------"); 
    break; 
    case 9:  
    Serial.println("--------------|----------------"); 
    break; 
    case 10: 
    Serial.println("--------------|-------------------"); 
    break; 
    case 11: 
    Serial.println("--------------|-----------------------"); 
    break; 

    } 
}

串行监视器只显示这些数字，是不断变化的：

总而言之，我希望如果有人能够帮助我以更简便的方式计算BPM，而无需处理BPM的可视化问题。

对不起，很长的文章，谢谢！

Arduino是不是C和不完全C++两种。不要垃圾标签。 – Olaf

答

这是我做到了，立交桥没有中断对我的板：

#define pulsePin A0 

// VARIABLES 
int rate[10];      
unsigned long sampleCounter = 0; 
unsigned long lastBeatTime = 0; 
unsigned long lastTime = 0, N; 
int BPM = 0; 
int IBI = 0; 
int P = 512; 
int T = 512; 
int thresh = 512; 
int amp = 100;     
int Signal; 
boolean Pulse = false; 
boolean firstBeat = true;   
boolean secondBeat = true; 
boolean QS = false;  

void setup() { 
    Serial.begin(9600); 

} 

void loop() { 

       if (QS == true) { 
       Serial.println("BPM: "+ String(BPM)); 
       QS = false; 
       } else if (millis() >= (lastTime + 2)) { 
       readPulse(); 
       lastTime = millis(); 
       }  
} 



void readPulse() { 

    Signal = analogRead(pulsePin);    
    sampleCounter += 2;       
    int N = sampleCounter - lastBeatTime; 

    detectSetHighLow(); 

    if (N > 250) { 
    if ((Signal > thresh) && (Pulse == false) && (N > (IBI/5) * 3)) 
     pulseDetected(); 
    } 

    if (Signal < thresh && Pulse == true) { 
    Pulse = false; 
    amp = P - T; 
    thresh = amp/2 + T; 
    P = thresh; 
    T = thresh; 
    } 

    if (N > 2500) { 
    thresh = 512; 
    P = 512; 
    T = 512; 
    lastBeatTime = sampleCounter; 
    firstBeat = true;    
    secondBeat = true;   
    } 

} 

void detectSetHighLow() { 

    if (Signal < thresh && N > (IBI/5) * 3) { 
    if (Signal < T) {      
     T = Signal;       
    } 
    } 

    if (Signal > thresh && Signal > P) {  
    P = Signal;       
    }          

} 

void pulseDetected() { 
    Pulse = true;       
    IBI = sampleCounter - lastBeatTime;  
    lastBeatTime = sampleCounter;   

    if (firstBeat) {      
    firstBeat = false;     
    return;        
    } 
    if (secondBeat) {      
    secondBeat = false;     
    for (int i = 0; i <= 9; i++) { 
     rate[i] = IBI; 
    } 
    } 

    word runningTotal = 0;     

    for (int i = 0; i <= 8; i++) {   
    rate[i] = rate[i + 1];    
    runningTotal += rate[i];   
    } 

    rate[9] = IBI;      
    runningTotal += rate[9];    
    runningTotal /= 10;     
    BPM = 60000/runningTotal;   
    QS = true;        
}

非常感谢。这绝对有效。我看到了BPM值，当串行监视器开始打印时，它以40s的正常范围开始，10秒内开始增加到200以上？我在想，如果这是我的mkr1000或代码故障？我有两个不同的脉冲传感器，它们都有相同的问题！此外，我还计划使用数字引脚来计算温度，并想知道是否有我应该小心的事情？再次，谢谢你。这真的有帮助！ – rp2402

欢迎您投票并接受答案。当添加其他传感器时，确保在计算BPM时增加延迟，当QS为真时，可以在第一个if语句内添加延迟 – Wadaane

关于跳跃式读数，这与传感器的质量以及您如何使用它有关，因为它使用反射光线，所以你需要确保它是隔离的。另外，我是如何添加一个if语句来检查BPM是否在一定范围内（40-100），当它不是我打印的“无效读取”时，再次，所有额外的代码都需要在第一个if语句中。 – Wadaane

答

我使用的传感器是DFRobot Piezo Disc振动传感器模块。

void setup() { 



Serial.begin(57600); 
} 

void loop() { 
    int avg = 0; 
    for(int i=0;i<64;i++){ 
    avg+=analogRead(A2); 
    } 
    Serial.println(avg/64,DEC); 
    delay(5); 
} 


void setup() { 
    Serial.begin(57600); 
} 

void loop() { 
    int avg = 0; 
    for(int i=0;i<64;i++){ 
    avg+=analogRead(A2); 
    } 
    Serial.println(avg/64,DEC); 
    delay(5); 
} 



When defining an arbitrary threshold (e.g. half of the maximum measured value), the rising edge of the signal will pass the threshold once per heartbeat, making measuring it as simple as measuring the time between two successive beats. For less jitter, I chose to calculate the heart rate using the average of the last 16 time differences between the beats.

代码计算的心脏速率，并在每一个节拍输出平均心脏率在过去16次：

int threshold = 60; 
int oldvalue = 0; 
int newvalue = 0; 
unsigned long oldmillis = 0; 
unsigned long newmillis = 0; 
int cnt = 0; 
int timings[16]; 

void setup() { 
    Serial.begin(57600); 
} 

void loop() { 
    oldvalue = newvalue; 
    newvalue = 0; 
    for(int i=0; i<64; i++){ // Average over 16 measurements 
    newvalue += analogRead(A2); 
    } 
    newvalue = newvalue/64; 
    // find triggering edge 
    if(oldvalue<threshold && newvalue>=threshold){ 
    oldmillis = newmillis; 
    newmillis = millis(); 
    // fill in the current time difference in ringbuffer 
    timings[cnt%16]= (int)(newmillis-oldmillis); 
    int totalmillis = 0; 
    // calculate average of the last 16 time differences 
    for(int i=0;i<16;i++){ 
     totalmillis += timings[i]; 
    } 
    // calculate heart rate 
    int heartrate = 60000/(totalmillis/16); 
    Serial.println(heartrate,DEC); 
    cnt++; 
    } 
    delay(5); 
} 



int threshold = 60; 
int oldvalue = 0; 
int newvalue = 0; 
unsigned long oldmillis = 0; 
unsigned long newmillis = 0; 
int cnt = 0; 
int timings[16]; 

void setup() { 
    Serial.begin(57600); 
} 

void loop() { 
    oldvalue = newvalue; 
    newvalue = 0; 
    for(int i=0; i<64; i++){ // Average over 16 measurements 
    newvalue += analogRead(A2); 
    } 
    newvalue = newvalue/64; 
    // find triggering edge 
    if(oldvalue<threshold && newvalue>=threshold){ 
    oldmillis = newmillis; 
    newmillis = millis(); 
    // fill in the current time difference in ringbuffer 
    timings[cnt%16]= (int)(newmillis-oldmillis); 
    int totalmillis = 0; 
    // calculate average of the last 16 time differences 
    for(int i=0;i<16;i++){ 
     totalmillis += timings[i]; 
    } 
    // calculate heart rate 
    int heartrate = 60000/(totalmillis/16); 
    Serial.println(heartrate,DEC); 
    cnt++; 
    } 
    delay(5); 
}

如果你想在家里尝试这个，只需连接模拟输出将传感器连接到A2（或更改代码）并连接传感器的5V和GND线。

脉冲传感器+ arduino mkr1000来计算BPM

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