Hey guys,I am a first time Arduino user and we are using this in our design project. My trouble lies in using the LCD. I got my LCD from modern devices, its the 16X2 blue back ground on white lettering. The LCD worked fine when I loaded the hello world example. When I loaded a different program, the LCD back light turns on and the LCD does not display what it is supposed to. One of the black circles on the back of the LCD got really hot. almost to the point where I cant touch it because of the heat. Did I somehow burned up the chip? My team mates checked the circuit multiple times so I am extremely positive it is connected properly.
is there any way to test the LCD to see if it is functioning properly without connecting it to Arduino
The most reliable way to get a chip as hot as you describe is to get the power leads reversed.
Even if your LCD module was not destroyed it was most likely damaged. In other words it may still seem to function normally under some conditions but some of its characteristics may have changed so that it no longer meets the manufacturer's specifications.
To check it out:
(1) Remove all of your current wiring.
(2) Connect the backlight, power, ground, and the contrast potentiometer but make no connections to the Arduino.
(3) You should be able to adjust the potentiometer to get a blank screen at one extreme setting and a single row of blocks at the other extreme setting. If you can't achieve this then stop here - it's credit card time.
(4) Adjust the potentiometer until the blocks are just visible.
(5) Connect the 6 logic lines between the LCD module and your Arduino and check out a known good sketch such as the 'Hello World' example.
Digimike: I used the examples from the lcd library. the second example was the scroll one
floresta: I am able to control the contrast of the LCD but the chip still gets hot. I checked to make sure the leads are not reversed and none of the pins are connected to the Arduino board. I will change the code a bit so the LCD uses different pins on the Arduino board and I will post teh results later today. Thanks for all your help so far