/*
  AnalogReadSerial
  WOKWI-Simulation: https://wokwi.com/projects/360903822433974273
  Discussion: https://forum.arduino.cc/t/millis-instead-of-delay-and-loop-instead-of-for-loop/1110044/2  
  
  Reads an analog input on pin 0, prints the result to the Serial Monitor.
  reading is done very often. Additionally a variable is counted up very fast
  incremented by 1 with each iteration of loop
  printing the value to the serial monitor is done only once per second
  the delay is realised WITHOUT function delay() with non-blocking timing
  Graphical representation is available using Serial Plotter (Tools > Serial Plotter menu).
  Attach the center pin of a potentiometer to pin A0, and the outside pins to +5V and ground.

  This example code is in the public domain.
*/

unsigned long fastCounter = 0; // variable fastCounter does demonstrate the fast looping of function loop()
unsigned long countSeconds = 0;

// the setup routine runs once when you press reset:
void setup() {
  // initialize serial communication at 115200 bits per second:
  // make sure to adjust the serial monitor to 115200 baud
  Serial.begin(115200);
  Serial.println( F("Setup-Start") );
}


// the loop routine runs over and over again forever:
void loop() {
  // increment variable fastCounter with every iteration of loop
  // for demonstration of how fast loop is looping
  fastCounter++;  

  doMeasuringPrintFromTimeToTime(); // call this function 
}


void doMeasuringPrintFromTimeToTime() {
  static unsigned long timeStamp;  // attribute static makes the variable persistant
  int sensorValue;

  sensorValue = analogRead(A0); // read the input on analog pin 0:

  // check if 1001 milliseconds have passed by since last measuring
  if (millis() - timeStamp >= 1001) {
    // when 1001 milliseconds REALLY have passed by
    timeStamp = millis(); // store actual time as new timestamp

    countSeconds++;       // increment variable countSeconds

    Serial.print( F("sec:") );    
    Serial.print(countSeconds);   
    Serial.print( F(" Value=") ); // print out the value you read:
    Serial.print(sensorValue);
    Serial.print( F(" counter counts up very fast=") );
    Serial.println(fastCounter);
  }
}