Thanks, that's exactly where it's going - behind dark tinted 3mm polycarbonate. However I still want to dim the backlight.
But is it pin 15 that should be broken - easy to do before assembly. The pot can be mounted between the screen and I2C pcb as I have lifted the I2C board 3mm using two short pieces of heat shrink at the end terminals before soldering from the center outwards. This also gives a nice space between the two boards.
For anyone there who is interested, I had to stop the annoying update blink screen refresh by this method - if anyone knows of another I would be interested.
In void loop()
lcd.setCursor(0,0); //sets beginning of line 1
lcd.print( your code for line 1);
lcd.setCursor(0,1); //sets beginning of line 2
lcd.print(your code for line 2);
// no more blink
Comment - this causes a refresh of each line without any blinking, giving a nice update of the sensor data.
is used the whole display will blink annoyingly - at least with this 2 line charactor lcd screen.
With my older Freetronics lcd screens that use 6 lines there is no blinking. Different tech.