Need help with loop time/interrupt programming

Projects Programming
10

Sorry to say but you should not use + addition with millis() compares , it is explained here - http://www.faludi.com/2007/12/18/arduino-millis-rollover-handling/ -

a retry which includes the value of millis(), give it a try

unsigned long T1=1000;
unsigned long T2=250;
unsigned long lastPressureTime=0;
unsigned long lastCalcTime=0;
int counter1=0;
int counter2=0;

void setup()
{
  Serial.begin(115200);
}

void loop()
{
  unsinged long now = millis();
  if (now - T1 >= lastPressureTime)
  {
    lastPressureTime += T1;

    Serial.print(now);
    Serial.print("\t ");
    Serial.println(counter1); // print every second
    counter1++;
  }  
  if (now - T2 >= lastCalcTime)
  {
    lastCalcTime += T2;

    Serial.print("\t\t ");
    Serial.print(now);
    Serial.print("\t ");
    Serial.println(counter2); // 4x /second
    counter2++;
  }  
}