Nokia LCD - random dots at bottom - why?


Sorry for it, if it is a dumb question :slight_smile:
I had to build a sample circuit for Nokia 3310 LCD, to see how it works. I haven't got any level shifters, so i used voltage divider resistors.
It is working, but at the bottom of the LCD, there is a sort of random dots, as you can see on this picture :

There is a capacitor between VOUT and ground, as recommended. I used the most common "Hello World" program :slight_smile:

Thanks for and ideas, why it happens :slight_smile:

PLEASE dont use rude pop-up sites like that on these forums, its very annoying.

You are experimenting with the stuff you have laying around, which can be lots of fun.
You're using a PC power supply and a veroboard Arduino.
So recycling is your thing, that's OK.
But you are also using the wires you have available, and apparently because you like to re-use those, you didn't cut them.
That's the most probable cause for your problem.
Those wires are much too long, and now also act as antennae.
They don't only send the data you want to send, they also pick up static and serve that to your display as data to be displayed.

Answer in short:
Don't use wires longer than they absolutely need to be.

Thanks, i will try with shorter wires.
(I haven't got much time for this project, and completely forgot this stream... :frowning: )

@MarkT : Sry, in the future i will use another.

You can upload photo’s directly to your post.
They will appear beneath your post as a thumbnail and blow up when clicked.
To do that, click on “Additional Options” and click the “browse” button next to the “Attach” field.
Follow the instructions and you’re done.

Yes, i noticed this right after that is sent that post... :smiley: