脉冲传感器 + arduino mkr1000 计算 BPM
pulse sensor + arduino mkr1000 to calculate BPM
tldr；使用脉冲传感器和 mkr1000 计算 BPM 的 easy/logical 方法是什么（对于初学者）？我不想要任何可视化或处理草图，而只是打印 BPM 值
请耐心等待，我是这方面的新手，我已经尽力理解并解决了这个问题，但徒劳无功。
我将脉冲传感器 (SEN-11574) 与 Arduino mkr1000 一起使用来计算 BPM 并将其打印在串行监视器中。我能够使用他们的入门代码
获得原始读数
// 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使用他们可用的示例代码计算 BPM on their website here
据我了解，Interrupt.ino 文件中的中断计时器功能与 mkr1000 不兼容。附上此代码供您参考。
// 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
在中断说明文件中，他们提到了与此代码不兼容的处理器的另一种变通方法，但即使按照说明进行了数小时后，代码仍无法正常工作，定时器中断函数再次出现错误.
接下来，我使用了 this guide，但同样，它也不起作用，只是打印不断变化的原始信号值 (S1023)。附上代码（2 个标签）：
/* 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
}
*/
串行处理文件：
//////////
///////// 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;
}
}
串口监视器只显示这些不断变化的数字：
S797
S813
S798
S811
S822
S802
S821
S819
S818
S806
S797
S797
S812
S816
S794
S820
S821
S808
S816
S820
S803
S810
S811
S806
S822
S817
S811
S822
S800
S820
S799
S800
S815
S809
S820
S822
S821
S809
S796
S821
S816
S798
S820
总而言之，我希望有人可以帮助我编写代码，以更基本/更简单的方式计算 BPM，而无需处理 BPM 的可视化。
抱歉这么久 post，谢谢！
我使用的传感器是 DFRobot 压电圆盘振动传感器模块。
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.
计算心率并在每次心跳时输出最近 16 次心跳的平均心率的代码：
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，只需将传感器的模拟输出连接到 A2（或更改代码）并连接传感器的 5V 和 GND 线。
我就是这样做的，以克服我的板上没有中断的情况：
#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;
}
tldr；使用脉冲传感器和 mkr1000 计算 BPM 的 easy/logical 方法是什么（对于初学者）？我不想要任何可视化或处理草图，而只是打印 BPM 值
请耐心等待，我是这方面的新手，我已经尽力理解并解决了这个问题，但徒劳无功。
我将脉冲传感器 (SEN-11574) 与 Arduino mkr1000 一起使用来计算 BPM 并将其打印在串行监视器中。我能够使用他们的入门代码
获得原始读数// 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使用他们可用的示例代码计算 BPM on their website here 据我了解，Interrupt.ino 文件中的中断计时器功能与 mkr1000 不兼容。附上此代码供您参考。
// 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
在中断说明文件中，他们提到了与此代码不兼容的处理器的另一种变通方法，但即使按照说明进行了数小时后，代码仍无法正常工作，定时器中断函数再次出现错误.
接下来，我使用了 this guide，但同样，它也不起作用，只是打印不断变化的原始信号值 (S1023)。附上代码（2 个标签）：
/* 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
}
*/
串行处理文件：
//////////
///////// 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;
}
}
串口监视器只显示这些不断变化的数字：
S797
S813
S798
S811
S822
S802
S821
S819
S818
S806
S797
S797
S812
S816
S794
S820
S821
S808
S816
S820
S803
S810
S811
S806
S822
S817
S811
S822
S800
S820
S799
S800
S815
S809
S820
S822
S821
S809
S796
S821
S816
S798
S820
总而言之，我希望有人可以帮助我编写代码，以更基本/更简单的方式计算 BPM，而无需处理 BPM 的可视化。
抱歉这么久 post，谢谢！
我使用的传感器是 DFRobot 压电圆盘振动传感器模块。
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.
计算心率并在每次心跳时输出最近 16 次心跳的平均心率的代码：
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，只需将传感器的模拟输出连接到 A2（或更改代码）并连接传感器的 5V 和 GND 线。
我就是这样做的，以克服我的板上没有中断的情况：
#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;
}