Nokia 5110 LCD Problem

Using Arduino Displays
1

Greetings all,

I recently purchased the Nokia 5110 LCD for one of my Arduino projects.

Initially, it works, but as time passes it becomes progressively darker.
To the point where reading the screen becomes impossible.

Removing the LCD from the breadboard, after shutting everything down, resolves the problem for a while.
Simply shutting everything down does nothing though.

I've tried various code solutions to this, like powering off the LCD before shutting down the Arduino, but the problem persists.

I'm not really keen on soldering this LCD to my prototype if I'm going to have this problem with it, so I'm holding off completion, until I have the issue properly identified.

Any advice would be greatly appreciated.

Notes:

  • I am using 3.3v, from the Arduino UNO R3 as power to the LCD. Should I perhaps be using a voltage regulator?
  • I'm using the PCD8544 library with a standard pin setup.
2

I'm currently working with a few similar models of the Nokia 5110 (5120i, 5165, 5190) but since I've pulled these from the actual phone; there is no "carrier" board except the one I'm making. If you could post your sketch and wiring diagram, I can do the same with mine and see if I have a problem also.
One thing to check - are you running on batteries or through the USB for power? Batteries can become weak and tired the older they get. and disconnecting them is kinda like letting them rest and start working normal again for a while.
As for the 3.3v power; if you've got the room for it, I'd put one on board. It wouldn't hurt and it'll also save the atmega.

3

Does it become darker due to an increase of contrast on the screen or a decrease in brightness of the LED backlight?