18. Apr 201918. Apr 2019

Using millis() instead of delay

millis() function returns the number of milliseconds the current sketch has been running since the last reset.

millis() returns an unsigned long.

#define MEASURE_INTERVAL 1000   // 
#define SEND_INTERVAL 16000   // 

unsigned long previous_millis_measure = 0;
unsigned long previous_millis_send = 0;

boolean measure_state = false;
boolean send_state = false;

void loop(void) 
{
  unsigned long current_millis = millis();
  
  if ((unsigned long)(current_millis - previous_millis_measure) >= MEASURE_INTERVAL)
  {
    measure_state = true;
    previous_millis_measure = current_millis;
  }

  if ((unsigned long)(current_millis - previous_millis_send) >= SEND_INTERVAL)
  {
    send_state = true;
    previous_millis_send = current_millis;
  }

  if (measure_state){ // == if true
    // measure something
    measure_state = false;
  }

 
  if (send_state){ // == if true
    // send something
    send_state = false;
  }

}