#define PROCESSING_VISUALIZER 1
#define SERIAL_PLOTTER  2
#include <SoftwareSerial.h>
//  Variables
int pulsePin = 0;                 // Pulse Sensor purple wire connected to analog pin 0
 
// 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.
SoftwareSerial BTSerial(2, 3);
 
// SET THE SERIAL OUTPUT TYPE TO YOUR NEEDS
// PROCESSING_VISUALIZER works with Pulse Sensor Processing Visualizer
//      https://github.com/WorldFamousElectronics/PulseSensor_Amped_Processing_Visualizer
// SERIAL_PLOTTER outputs sensor data for viewing with the Arduino Serial Plotter
//      run the Serial Plotter at 115200 baud: Tools/Serial Plotter or Command+L
static int outputType = SERIAL_PLOTTER;
 
 
void setup(){
  BTSerial.begin(9600); 
  Serial.begin(9600);             // 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(){
 
    serialOutput() ;
    BTSerial.print(BPM );
    delay(1000);
  if (QS == true){     // A Heartbeat Was Found
                       // BPM and IBI have been Determined
                       // Quantified Self "QS" true when arduino finds a heartbeat
                                // 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
  }
}
 
위처럼 심박 측정 코드를 작성하고 앱인벤터로 앱을 만들어 실행시켜 보았는데 측정된 심박수가 일정하게 한개 씩 나오다가(ex: BPM:90) 갑자기 두개가 겹쳐서 나오는 현상이 발생합니다.(ex: BPM:9091) 원인이 무엇인지 알 수 있을까요?