Arduino Program (The Code) - piezo_sensor_with_graph.ino

Written in C++ on the Arduino IDE

const int knockSensorPin = A3;   // Pin connected to the piezo sensor
const int ledPin = 13;           
// Pin connected to the LED 
//LED Connected on Pin 13 of the PWM - pulse-width modulation on the Arduino

int threshold = 200;             
// Adjust this value to set the knock sensitivity. 

//A higher threshold means that a stronger or more pronounced knock would be required to exceed the threshold and trigger the action. 

//On the other hand, a lower threshold would make the system more sensitive, allowing even weaker knocks to be detected.


void setup() {
  pinMode(ledPin, OUTPUT);     // Set the LED pin as an output
  Serial.begin(9600);          // Initialize the serial communication at a baud rate of 9600. 
}

//Baud rate is the rate at which the number of signal elements or changes to the signal occurs per second when it passes through a transmission medium.

void loop() {
  int sensorValue = analogRead(knockSensorPin);  // Read the sensor value. Reads the voltage level from the analog pin and converts it into a digital value. This digital value represents the sensor reading, which we refer to as the "sensor value" in this code.

 //"Sensor Value" refers to the reading obtained from the piezo sensor connected to the Arduino's analog pin. 

  if (sensorValue >= threshold) {
    digitalWrite(ledPin, HIGH);  // Turn on the LED
    delay(100);                   // Delay for LED visibility
  } else {
    digitalWrite(ledPin, LOW);   // Turn off the LED
  }

  // Send the sensor value to the serial plotter
  Serial.println(sensorValue);
  delay(50);  // Delay between readings for stability
}