LCD Trouble

Forum 2005-2010 (read only) Hardware Troubleshooting
1

I am new to the Arduino community (received it late Friday) and have gone throught the tutorials on Ladyada's site and a few others. I am now working on connecting an LCD, but I am not getting anything at all. No backlight, no Characters nothing. Is there a way to test thesee to see if it is DOA? Or is it possible the contrast is all the way down?? I hoooked up the 5v to the VDD and Gnd to the Vss on the lcd to see if I could get it to power and still couldnt get anything. Here is the LCD that I picked up from NKC Electronics at the same time as the Arduino.

nkcelectronics.com/16x2-lcd-module-while-characters-blue-backli162.html

If I have asked an already answered question, please let me know the correct wording, I did a search for LCD power test, and all posts with LCD and didn't see anything releated.

Thanks

2

The backlight LED is on pins A and K. You need to connect +5V to A and GND
to K to get a backlight.

The other thing to check is the contrast pin (which I believe is V0 on your LCD)
IIRC grounding the contrast pin gives maximum contrast.

A schematic of my LCD board is at Loading...
The pinout of the Optrex 51505 that I use is different than your LCD
so adjust the wiring appropriately.

(* jcl *)

3

jluciani,
Thank you very much for the reply! I got the LCD to display the Boxes across the screen but still haven't gotten the backlight to come up yet. I'll keep messing with it to see what I can do. Although you did help me in that I found that it will at least power and does it's test screen. MUCH APPRECIATED!

Dan

4

Check the polarity of the connections to the diode. A is anode which should have +5V.
K is cathode which should be at GND.

(* jcl *)