To calculate rpm in arduino

 To calculate RPM (Revolutions Per Minute) based on a continuous input signal in Arduino, you can use the following code:

const int inputPin = 2;    // Input pin for the continuous signal

unsigned long prevTime = 0;  // Previous time for calculating time difference

volatile unsigned int pulseCount = 0;  // Counter for the number of pulses

void setup() {

  Serial.begin(9600);

  pinMode(inputPin, INPUT_PULLUP);

  attachInterrupt(digitalPinToInterrupt(inputPin), countPulse, RISING);

}

void loop() {

  if (millis() - prevTime >= 1000) {

    // Calculate RPM

    float rpm = pulseCount * 60.0 / (millis() - prevTime);

    // Reset pulse count and update previous time

    pulseCount = 0;

    prevTime = millis();

    // Output RPM

    Serial.print("RPM: ");

    Serial.println(rpm);

  }

}

void countPulse() {

  pulseCount++;

}

In this code, we declare the input pin for the continuous signal as inputPin. We also declare a variable prevTime to store the previous time and pulseCount to keep track of the number of pulses.

In the setup() function, we initialize the serial communication, set the input pin as an INPUT_PULLUP, and attach an interrupt to the rising edge of the input signal using attachInterrupt().

In the loop() function, we check if one second (1000 milliseconds) has passed since the last calculation. If so, we calculate the RPM based on the pulse count and the time difference since the previous calculation. We then reset the pulse count and update the previous time.

The calculated RPM value is printed to the serial monitor using Serial.println(). Adjust the baud rate (Serial.begin()) and the output format according to your needs.

The countPulse() function is the interrupt service routine (ISR) that increments the pulse count variable each time a rising edge is detected on the input pin. The attachInterrupt() function is used to assign the ISR to the input pin.

Upload the code to your Arduino board using the Arduino IDE, and you should see the calculated RPM displayed in the serial monitor. Ensure that the input signal is connected to the specified input pin.