Barebones Pulse code.

PulseSensorBasic.pde

/*
THIS PROGRAM WORKS WITH PulseSensorAmped_Arduino-xx ARDUINO CODE
*/

import processing.serial.*;

Serial port;     

int Sensor;      // HOLDS PULSE SENSOR DATA FROM ARDUINO
int IBI;         // HOLDS TIME BETWEN HEARTBEATS FROM ARDUINO
int BPM;         // HOLDS HEART RATE VALUE FROM ARDUINO

void setup() {
  size(700, 600);  // Stage size
  frameRate(60);  
   
// GO FIND THE ARDUINO
  println(Serial.list());    // print a list of available serial ports
  // choose the number between the [] that is connected to the Arduino
  port = new Serial(this, Serial.list()[0], 115200);  // make sure Arduino is talking serial at this baud rate
  port.clear();            // flush buffer
  port.bufferUntil('\n');  // set buffer full flag on receipt of carriage return
}
  
void draw() {
  background(0);
  
  // just print values to the console
  println("BPM=" + BPM);
  println("IBI=" + IBI);
  println("Sensor=" + Sensor);
  println("-----------------");
  
  // TODO: your logical if/then statements would go here
  
  
}  //end of draw loop

void serialEvent(Serial port){ 
   String inData = port.readStringUntil('\n');
   inData = trim(inData);                 // cut off white space (carriage return)
   
   if (inData.charAt(0) == 'S'){          // leading 'S' for sensor data
     inData = inData.substring(1);        // cut off the leading 'S'
     Sensor = int(inData);                // convert the string to usable int
   }
   if (inData.charAt(0) == 'B'){          // leading 'B' for BPM data
     inData = inData.substring(1);        // cut off the leading 'B'
     BPM = int(inData);                   // convert the string to usable int
   }
 if (inData.charAt(0) == 'Q'){            // leading 'Q' means IBI data 
     inData = inData.substring(1);        // cut off the leading 'Q'
     IBI = int(inData);                   // convert the string to usable int
   }
}