Meaning of threshold value

Using Arduino Sensors
1

Hello everyone , I using this code for my piezo disk sensor.

int led=4;
int sensor=A0;
int threshold=400;
void setup() {
  pinMode(4,OUTPUT);
  pinMode(A0,INPUT);
 Serial.begin(9600);
}

void loop() {
  int value=analogRead(sensor);
  if (value>=threshold)
  {
    digitalWrite(4, HIGH);
    delay(100);
    
  }
  else
  digitalWrite(4, LOW);
  Serial.println(value);
}

Can someone please tell me, what is the significance of threshold value in this code?

2

If the analog value is above or equal to the threshold value then the digital output 4 is set high , else it’s set low ( ie it’s below thaw threshold value) .

3

It is basically to avoid tiny little bumps on the sensor counting as full scale hits. You can adjust the value of threshold to suit your sensor and how you're using it.

Steve

4

I guess it's meant to be a minimum reading, allowing you to ignore small signals (and noise).

5

thanks everyone

6