// For: https://forum.arduino.cc/t/read-ac-frequency-with-arduino/1063205

#include <toneAC.h>

// Define the input pin for the pulse signal
// Define the input pin for the pulse signal
#define pulse_ip A1

// Declare variables to store the calculated values
unsigned long ontime, offtime, freq, period;
unsigned long count = 0;

void setup() {
  // Set the input pin to input mode
  pinMode(pulse_ip, INPUT);

  // Initialize the serial monitor
  Serial.begin(9600);

  toneAC( 100000UL);       // output 100kHz at pin 8 and 9
}

void loop() {
  Serial.print( count++);
  Serial.print( ",");

  // Measure the on time and off time of the pulse signal
  ontime = pulseIn(pulse_ip, HIGH);
  offtime = pulseIn(pulse_ip, LOW);
   
  // Calculate the period, frequency
  period = ontime + offtime;
  freq = 1000000.0 / period;
    
  // Print the calculated values to the serial monitor/change to lcd later
  Serial.print("Frequency: ");
  Serial.print(freq);
  Serial.print(" Hz");
  Serial.print(", On time: ");
  Serial.print(ontime);
  Serial.print(" us");
  Serial.print(", Off time: ");
  Serial.print(offtime);
  Serial.println(" us");

  // Wait for half second before repeating the process
  delay(500);
}