LCD2004 I2C Sunfounder can't display anything

Other Hardware Displays
1

Hi Guys,
I have just acquired a LCD2004 I2C by Sunfounder from here: https://www.amazon.co.uk/gp/product/B01GPUMP9C/ref=oh_aui_detailpage_o01_s00?ie=UTF8&psc=1

I am using the LiquidCrystal_I2C library and have scanned my device to make sure the address is 0x27. I have connected it to the SDA and SCL onto the corresponding pins on the MEGA and I cannot get it to display anything, even when using the library examples. If i turn the potentiometer sufficiently high, all I see is the first and 3rd line with white squares. Any help would be greatly appreciated as I am not sure what I am doing wrong!
Thanks!

2

I am using the LiquidCrystal_I2C library

There is no such thing as 'the' LiquidCrystal_I2C library. There are several of them, many with the same name.

. . . even when using the library examples.

Have you tried the library that is recommended in the majority of the forum posts dealing with this sort of problem? You have looked them over I assume.

. . . all I see is the first and 3rd line with white squares.

For starters leave the potentiometer set to a position that shows those squares.

Don

3

There is a lot of info here for that LCD. All the steps to get it to work.
https://www.sunfounder.com/wiki/index.php?title=I2C_LCD2004

4

@tombauer:

There is a lot of info here for that LCD. All the steps to get it to work.
https://www.sunfounder.com/wiki/index.php?title=I2C_LCD2004

I suspect that the OP used just another library he found somewhere which is not compatible to the constructor he is using.

But you have to make sure that he downloads the "right library" which sunfounder is using in their test sketches:
This is the one they are working with:
http://www.sunfounder.com/wiki/index.php?title=File:LiquidCrystal_I2C.zip

@elt93:
Before you install the above linked library, pls DELETE ALL PREVIOUS lcd libraries from your PC as the Arduino compiler might stumble and choose the wrong one again, when you have installed multiple libraries with the same name.

5

Thank you all so much for your help, I implemented the right library and this now works perfectly.