Danois90:
Hard to help when you post partial code that does not work.
Here the complete code:
#include <LiquidCrystal.h> // initialize the library with the numbers of the interface pins
LiquidCrystal lcd(7, 8, 9, 10, 11, 12);
int sensorInterrupt = 0; // 0 = digital pin 2
int sensorPin = 2;
// The hall-effect flow sensor outputs approximately 4.5 pulses per second per
// litre/minute of flow.
float calibrationFactor = 6;
volatile byte pulseCount;
float flowRate;
unsigned int flowMilliLitres;
unsigned long totalMilliLitres;
unsigned long oldTime;
int sensorValue = 0;
//Stopuhrkram
int ledPin = 13; // LED connected to digital pin 13
int buttonPin = 5; // button on pin 5 (Only needed when button is used)
int value = LOW; // previous value of the LED
int buttonState; // variable to store button state (Only needed when button is used)
int lastButtonState; // variable to store last button state (Only needed when button is used)
int blinking; // condition for blinking - timer is timing
int frameRate = 10; // the frame rate (frames per second) at which the stopwatch runs - Change to suit
long interval = (1000 / frameRate); // blink interval
long previousMillis = 0; // variable to store last time LED was updated
long startTime ; // start time for stop watch
long elapsedTime ; // elapsed time for stop watch
int fractional; // variable used to store fractional part of time
int fractionalSecs; // variable used to store fractional part of Seconds
int fractionalMins; // variable used to store fractional part of Minutes
int elapsedFrames; // elapsed frames for stop watch
int elapsedSeconds; // elapsed seconds for stop watch
int elapsedMinutes; // elapsed Minutes for stop watch
char buf[10]; // string buffer for itoa function