Being cautious of LCD burnout?

I've got a newhaven lcd display (https://www.onlinecomponents.com/datasheet/nhd0208azflybw.aspx?p=37682425) that I'm using the LiquidCrystal library with, and I'm wondering how concerned I should be about the display burning out or going bad for some reason after being on for a long time. The application I'm going to be using the display for would pretty much have it turned on 24/7 if I don't put some measures in place to put it into a sleep mode or something until someone interacts with it.

Does having the backlight contrast tied to something slightly higher than 0V affect anything? (right now I've just got it tied to ground but could tie it to a potentiometer instead). Is there a way to turn the display completely off until I give it some sort of wake up command?

I'm actually not programming this on an arduino but a Particle Photon, but I thought I would post this here as well as over on the particle forums to get as good of advice as possible. Here is my current pin configuration:

  • LCD RS (4) pin to photon pin D0
  • LCD EN (6) pin to photon pin A1
  • LCD D4 (11) pin to photon pin D2
  • LCD D5 (12) pin to photon pin D4
  • LCD D6 (13) pin to photon pin A2
  • LCD D7 (14) pin to photon pin A3
  • LCD VO (3) to GND
  • connect R/W (5) to ground

plus the VDD pins to 5V.

I've got the display working just fine, just wondering if anyone knows precautions that I should be taking to extend the lifetime of this display as long as possible, or if I just have nothing to worry about. Thanks!

"Is there a way to turn the display completely off until I give it some sort of wake up command?"

Have you considered using the display() and noDisplay() functions? These affect only the display, not the LCD controller, so whatever was on the screen before you turn it off will reappear when you turn it back on.

These are generally used to keep the display from being a distraction, I doubt they affect the life of the display one way or the other.

Don

I was wondering that.

The big concern about LCDs is that DC will kill them. The display drivers are especially designed to avoid this. The HD44780 and clones presumably shut down all drive to the LCD from the contrast ladder on noDisplay(). The question is, granted current LCDs have a decent life in practice, does driving them eventually cause damage because the AC drive represents a lot of tiny bits of DC - and that beyond the simple course of time?

The LED backlight is the real concern.
The backlight will get dim long before the LCD itself will have issues.
The backlight lifespan is not given in the datasheet you provided, but
many LEDs have usable lifespan rating of about 50,000 hours. If you use that, then you are looking at around 5 years if the backlight is on all the time.
But that depends on how much current is being fed to the LED backlight and the actual rating of the LEDs used.
It could be much shorter.

If you are concerned about it, I'd look at using an I2C backpack.
They have backlight control circuitry so you can turn the off the backlight when the LCD is not in use.

--- bill

carsongmiller:
Does having the backlight contrast tied to something slightly higher than 0V affect anything? (right now I've just got it tied to ground but could tie it to a potentiometer instead).

Noting your comment "backlight contrast".

There is a tendency to confuse two entirely different things. The backlight is the LED connected to pins 15 and 16. On the one you cite this takes an unusually high current (100 mA) and to control it on and off, you would need a transistor to switch it under control from your MCU.

The contrast control on pin 3 controls just that - the black/ yellow contrast on the display. The datasheet shows a stupid blunder mindlessly copied since the early days of these displays, the contrast potentiometer should not connect to Vcc - 5 V - but only one end to ground, and its value should be 1k, not 10 or 20 which would only operate very close to one end of the travel.

In any case there is neither need nor benefit whatsoever to fiddle with the contrast voltage to "reduce stress" on the display. Calling noDisplay() will - if needed - shut off the drive.