Lcd Backlight question for a newby

Other Hardware Displays
1

Gday all,

I would like to know if i have wired something wrong as i an only just starting out with Arduino so please excuse what some people might find silly question.

i have just read through the getting started with Arduino and done the examples and am starting to understand a very little bit only so i have gone to learning and tried to complete the "hello world" example and i think i have done every thing right but i can see the words hello world but no backlight and in the code i cant see backlight any where.
so my question is is there no backlight suppose to be on now (i am hoping so) or have i done something wrong and if so how do i test it to make sure the backlight is not faulty on the shield?

thanks for any help
Maury

2

Sorry should of added what i have

Arduino Duemilanove
16x2 lcd

3

Hey there,

Two things:

  • We need the model and, if you have it, the datasheet for it
  • Are you using the wiring as in the example, using the same pins, etc?
4

In spite of the reference to a "16-pin interface" in the LiquidCrystal tutorial the Hitachi LCD interface only deals with 14 pins. The backlight circuitry, which is connected to pins 15 and 16, is completely separate from the display circuitry and the LiquidCrystal library only deals with the display portion.

Typically pin 16 is connected to GND and pin 15 is connected to the +5v supply. You will have to consult the data sheet for your particular display to determine if you need to insert a series current limiting resistor in the +5 volt line or if the resistor is already present on the LCD pc board.

Don

5

thanks all for your reply i have got it going now with resistor