Arduino i2c for 16x2 lcd no backlight or text after upload [solved]

Other Hardware Displays
16

Finally i got to test it.

This is what worked for me.

#include <Wire.h> 
#include <LiquidCrystal_I2C.h>


LiquidCrystal_I2C lcd(0x27, 2, 1, 0, 4, 5, 6, 7, 3, POSITIVE);

void setup()
{
  lcd.begin(16,2);                
  lcd.home ();                   
  lcd.print("Arduino i2c ");  
  lcd.setCursor ( 0, 1 );        
  lcd.print (" Test lcd!   ");
  delay ( 1000 );
  lcd.clear();
}

void loop()
{

  lcd.home ();
  lcd.print("testtest");
  lcd.setCursor(3,1);
  lcd.print("more test");
  delay (200);
}

But what about that "POSITIVE"? I I think i cannot control the backlight with arduino or can i? Without soldering an output to jumper.

If i only use this: LiquidCrystal_I2C lcd(0x38);  // Set the LCD I2C address
I get a blinky LCD.