Why does pulse sensor shows gaps when I move it?

Question

I modified the serial code in this way and I don't think the gap is produced by my edit even because it made it even before:

//////////
///////// 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
 //ASCII Art Madness
 Serial.print(BPM);
 Serial.println("");
 } 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("");
 } 
}
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You can find all the code here: https://github.com/WorldFamousElectronics/PulseSensor_Amped_Arduino

In the code I posted there is some code I don'f find useful but I can't delete it for reason linked to variables used for other functions I don't know I'm using. You can also see huge changes in the heart rate that surely don't reflect the reality.

• RSM: probably because of the badly formatted switch() case: statement. Have a look at what the Serial.println('"");
• Gabriele Giordano: that's where I deleted things
• Gabriele Giordano: ok I deleted the code there and now no problem. Any idea on how to fix the erroneous heart rates?
• RSM: That might be something with the sensor and how it is connected, loose connections possibly.
• sa_leinad: Try using another serial terminal program (such as br@y terminal, Hterm, YAT etc.). In these programs you can control the timeout and also view line breaks.

Answer 1

One of the possibilities is when you move your finger, the sensor grip loosened and doesn't count a "beat". So the sensor emits data = 0, and it will cause

Serial.println(""); 

in your switch-case.

• SDsolar: Upvote because this seems most likely. If changing code doesn't matter, and the wiring is intact, then it must be the movement that is causing it. Like the old joke: "Doctor, it hurts when I lift my arm" and the Doctor says, "Then don't lift your arm"