Sample High Pass Filter in Arduino

high-pass-filter.ino

float alpha = 0.1; // Filter constant, lower value means more filtering
float prevValue = 0.0; // Previous filtered value
float filteredValue;

void setup() {
  Serial.begin(9600);
}

void loop() {
  float rawValue = analogRead(A0); // Read the raw analog input

  // Apply the high-pass filter
  filteredValue = rawValue - (prevValue * alpha);
  prevValue = rawValue;

  // Print the filtered value
  Serial.println(filteredValue);

  delay(10); // Delay to control the sampling rate
}