Is it possible to adjust I2C LCD with code If so how
What exactly do you want to adjust ?
contrast
It's usually accomplished with an external potentiometer; I've seen somewhere circuits to use an electronic potentiometer to do the same thing, but I'd question my sanity unless I had a darn good reason to go down that rabbit hole.
I note that you have revised the title of the topic to explain what you want to adjust thus making my question in post #2 look silly
This is very bad manners
@UKHeliBob
IMHO he's too newbie to indict, maybe cut him some slack. Doesn't know forum etiquette, may not have read "how to" yet...
Posted 3 hours ago
Joined 2 days ago
Read 29m
Which exact I2C LCD? There is more than one kind.
Please read the how to get the most from the forum post. The post contains information on what we need to know in order to help you.
He has visited for 3 days, viewed 12 topics and read 80 posts, will have been directed to the advice on how to use the forum when he joined and has had plenty of time to read it and see examples of it in practice
Even without any of that what he did was still bad manners and it should have been obvious that it could cause confusion
sorry about that I was unaware that it is bad manners
128x64 graphical lcd
Have you tried attaching pot and controlling the contrast like is shown on this page? >> A Tutorial on Interfacing 128x64 Graphical LCD with Arduino | Tutorial
yes but how would I do it with I2C
That I do not know.
What library are you using to control the LCD?
Can you post a data sheet or other documentation for your LCD? The 128x64 monochrome graphical LCD that I am familiar with has an SPI or parallel interface, not I2C.
I am using the library I2C_LCD12864 and I am using a 12864B V2.0 LCD with a 1602/12864/2004 I2C expander
You would need to set up a digitally controlled pot of the same value, wired in place of the existing I2C backpack pot. Then the digital pot can be controlled separately from the LCD.
per post #4. Forgive me for being ahead of my time! 
1 Like
Got lost amongst the nagging to the OP.
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