Replacing old LCD

Hi guys, this topic isn’t about Arduino, but I think you guys have the most experience with LCD Displays.

I have a farming machine where the LCD stopped working. It is a 16x1 Display and on the Backside “cmc116l01” is written on it. Can I replace it with any other LCD Display which has 16x1 and the same inputs or is this a waste of time?

I added a Picture of the LCD Display and one of a description on a cmc116l01 Display.

I really hope you guys can help me
best regards

It looks like it uses the typical/standard 5v hd44780 pinout.
That said, there are two types of 16x1 displays and they internally address memory/characters on the display differently so while they both work the same electrically, they don't address the characters on the display the same way.

1 type is an actual 16x1 display and the other actually a 8x2 with the 2nd line or 8 characters butted up to the first to form a single 16 character line on the LCD display.
This makes addressing the characters for the right 8 characters work differently on the two displays.

You want to wait for Don "Floresta" to chime in as he has the most knowledge on the 16x1 vs 8x2 displays and how to identify them.

You also may want to verify the voltage. Look at the voltage on pins 1 & 2 and verify that it is around 5v.


Out of curiosity, what is the equipment?

If you think you might need to replace it again, then you may want consider using a header on it depending on the physical room you have.
This would keep from having to disturb and resolder the wires.
You would solder the wires to a 16 pin female header and then solder a 16 pin male header or 90 degree header to the LCD.
Then you just slide on the female header.
To replace in the future just solder on a 16 pin male header and connect the female header - no having to solder or mess with the potential delicate wires.

--- bill

I'm here.

It looks like your display uses only one HD44780 chip (epoxy blob) so it is the type that performs like an 8x2.

You can replace it with another 16x1 that has only one chip but not with the kind that has two.

A 16x2 display should also function without any smoke but your messages will be split in half - with the 8 characters that should be on the right hand side positioned underneath the 8 characters on the left side.

Don

floresta:
A 16x2 display should also function without any smoke but your messages will be split in half - with the 8 characters that should be on the right hand side positioned underneath the 8 characters on the left side.

That is what I was thinking.

Under the circumstances, that sounds perfectly adequate to me! :grinning:

Paul__B:
That is what I was thinking.

Under the circumstances, that sounds perfectly adequate to me! :grinning:

I wouldn't use a 16x2, even if it fits in the original device, the information on the display would not be correctly formatted as it would split across the two lines rather than being all on one line.

I'd look for a 16x1 display. Depending on how fast it was needed might determine the source.

The other thing we don't know is the font size on that display.
Most of the displays I see use 5x8 dot font size vs the larger 5x10 font.

Assuming it was a 5x8 dot display and there was time, I'd just order one/some from Ebay.
Several of the vendors on Ebay show the back of the LCD module so you can verify the type of display.

--- bill

Thank you guys for the fast response.

So this LCD from Amazon should work?

best regards

More than likely that would work.
Not sure which type of LCD you wanting.
Are you looking for dark blue with white text LCD?
That type of LCD is not very readable outdoors in sunlight.
For outdoor use, the type with black pixels on a greenish/yellow background can be seen in direct sunlight.

--- bill

When "White on Blue" LCDs arrived on the hobbyist market I thought they looked cool.

In hindsight, the "Black on greenish-yellow" type are more practical.

  1. you do not need backlight except at night.
  2. you can read in daytime or even direct sunlight.
  3. they are available with backlights in other colours than greenish-yellow.
  4. contrast is less critical for readability. It is still worth adjusting for optimum.
  5. they are readable at a wider angle.
  6. when backlight is off, they take very little current e.g. for battery apps.

David.

david_prentice:
6. when backlight is off, they take very little current e.g. for battery apps.

Only half as much current again if you correct the near-universal published design foul-up of connecting the contrast pot to Vcc. It should connect only to “Vo” - pin 3 - and ground.

Go on. Do the maths. Yes, we all understand that a pot is unnecessary and unwise.

As I understand, there is an internal 10k pullup to VCC on VO pin. So a single external resistor from VO to GND is all that is required. e.g. 470R

This means that approx 500uA is drawn from a 5V supply. (5.0V / 10470R)

If a 10k pot is wired to VCC, VO, GND you will have an additional parallel load on VCC of approx 500uA.
And the same contrast will be be set when the pot is about 235R / 10K.

Yes, the adjustment range is only a fraction of the pot.
If you use a 1k variable resistance instead of a 10k pot you can adjust over the full range of 0 - 1k. Easily setting the 470R typical value.

Compare this "extra 500uA" with the typical 5mA operating current of the LCD module.

Now compare 500uA or 1000uA to the typical 20mA - 50mA drawn by the backlight.

People have been using 3-terminal pots for the last 30 years.
However many times you repeat the mantra they are unlikely to change.

David.

david_prentice:
Compare this "extra 500uA" with the typical 5mA operating current of the LCD module.

What is it that draws 5 mA? The specification for the HD44780 is 600 μA. Are the "clone" chips in these modules now, massively inefficient?

david_prentice:
Now compare 500uA or 1000uA to the typical 20mA - 50mA drawn by the backlight.

That is of course, always the point. :grinning: But that is why on battery power, you wish to turn off the backlight. No problem there. :roll_eyes:

david_prentice:
People have been using 3-terminal pots for the last 30 years.
However many times you repeat the mantra they are unlikely to change.

And yes, people have been using Windoze for almost as long! :astonished: