LCD from an old LBP-4 Canon printer?

I have such an LCD with a connection formed as a 10 wire flat cable.

The PCB has a number made in copper:


How can I use this in combination with an Arduino Uno ?

I took these pictures:!Ap0XTBN0ykvEjPU_xWq2wDlPkMAPHw?e=CTm8wK

Perhaps you should first tell us a bit more about the project. And why do you want to use that LCD?

Oh, the project is nothing special, just managing two air pumps for my garden pond - they tend to be too hot on a warm summerday and the project should just turn them on and off one at a time.

The LCD was just laying in the box of reuseable compoments - too, nothing special there !
I want to use the LCD for showing the temperature of each air pump - I have the temp.sensors to work, but feels I need to see the data when the project is running in the garden.

I would check first if it's compatible with written libraries for LCDs. Then you can use this example.

If it's not compatible with standard LCDs, it's a bit more complicated. Then you can try it with registers. By looking in the datasheets of the microcontrollers on the LCD, you can find out how the LCD can be controlled. (reading and writing the correct registers)
Keep in mind that this is not easy and will take a lot of time.
You can always buy a standard LCD, so you can save yourself a lot of time...

I would peel off the white label and see what information you can obtain from the top of the chip as that may guide you more than the writing on the PCB.

Ha, ha, how will you find out if it's compatible when I know NOTHING about it at all ?

The chip is marked:
1J1 8

and I found some videos out there ... I'll try to see what they explain !


The HD44780 is your basic LCD driver chip. There's loads of information out there on how to drive it. You just need to figure out the pinout of the connector and you should be good to go.

Yeah, I've seen the videos I found in the first place, but they all concern the type of board with the 16 pins in the top - and mine have only a 10-wire flat cable as connection !
From the datasheet I can find the GND on the chip but can't trace it to the flat cable because it's running under chip/connector and through-holes ect. :joy:

If you have 10 wires, then it's probably wired for 4-bit mode.

Sparkfun (amongst others) has a datasheet for the HD44780. You should use that (or similar datasheet) to do a continuity check for each of your 10 wires to the chip.

If it is 4-bit mode, then I believe that it's using the RS, R/W, E & DB4-DB7 pins - 7 pins in total. Add in a supply and ground and maybe backlight on/off and that'll make 10 connections.

I have to access each pin you mention on the chip and then the 10-wire flat cable.

Can I do that 'continuity check' with out damaging the HD44780 ? :thinking:

You should be able to check the continuity using a basic multimeter without damaging the chip. Obviously without any power to the board.

OK, I'll try and let you know the result !

BTW, I found a bigger LCD 4 X 20 chars in the drawer with the 16 pinout - I'll try use that in the first place :crazy_face:

I now tried the 'continuity check' and found these pin/connections for the 10 flat wire:

GND / R/W (W is 'over-scored')

That's the 10 wires and R'W' is grounded on the PCB somewhere !
Then I too found 4 un-used solder pads for DB0 .. DB 3 !

How should RS and E be connected to check the LCD ?

That looks good. Here's a link to the Arduino LiquidCrystal library page. It says that the library supports 4-bit mode.

As for the actual wiring, the constructor shows the parameters to the call for 4-bit mode.

LiquidCrystal(rs, enable, d4, d5, d6, d7)

If you look at the Hello World example (previously linked to by @laura2000 above), then it details how to wire up an LCD using 4-bit mode.

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