Solved ✔: LCD shows strange cryptical Characters on LCD LiquidCrystal I2C and ESP32 nodeMCU Arduino

Solution on codedocu.de
Include Wire.h
Wire.SetClock(10000);

[@manuelkoch2659]

1000 points for this. Solved my issues after hours of struggling. Unfortunately this problem seams to be common but nobody got this answer like you. Thanks a lot.

[@takevanpopta3892]

to follow up, in a video from the dronebot workshop about i2c i found the advice to use 10k pull up resistors on the SDA and SCL line. This also solved the problem for me.

[@albertomanske7379]

Thanks for that explanation, just one more info, do you also use resistors for pull-up?

[@astrawally8448]

Realise that this is an old video but the issue here is earthing of the LCD causing logic levels to be all over the shop.
At 0:16 the whole LCD momentarily shuts down (back light dims and displayed characters are corrupted) and I can almost guarantee that the LCD and LED board earths (the pad around the screw hole) touch / disconnect and create the earthing issue.
Reducing the clocking speed has likely masked the issue and reduced the likelihood of it happening.
Run proper grounding across all boards and the issue will go away.
I'd love to see the black/white/grey wiring running to the LCD board, from memory if this is a 1602A it will need board power and ground and the LCD back light has its own (current limited) power supply.

[@therealskoodle705]

Holy Crap dude that was super helpful, one piece of code for something i thought was too complex that would take forever to figure out lol Thanks again my guy.

[@chiranthmurthy1164]

Awsome dude implemented it and not found errors and struggled for 4 months to rectify this error thanks in advance.

[@davemartin7374]

Thank you so much!! I had the same problem on an ESP-32 which you solved for me!

[@gabrielgomesdossantos5244]

Mine with a few seconds began to appear strange characters ... 100% solved! Thank you man

[@lucianoalfredo4249]

I have similar problems with my lcd. Hope this work. Thanks alot!

[@DiogoSanti]

Thanks for this, it was driving me crazy... just slow down I2C...:)

[@PFLMCTT]

Thanks!
Just a small correction:
In the video description, the code is Wire.SetClock(10000) the correct is Wire.setClock(10000), not with a capital S on set.
If you just copy paste it won´t work.

[@user-hr5dc4ly3q]

Error not solved when timer runing and relay open and closed 😢

[@marcelogonzalez7132]

Thanks a lot I was struggling for hours with it

[@TheEmperor2052]

For all you working with the Raspberry Pi and experience the issue with the LCD showing strange characters after some time; one workaround is after every time your relay goes to low or high power, reinitialize the LCD. It is not a perfect solution since it does not remove the main issue, but it works.

[@anurajn2616]

Thanks alot buddy. Wire.setClock(10000);// "s" is small letter, do not copy paste what he written

[@belabertalan]

Best solution!

[@takevanpopta3892]

Thanks a lot!

[@washim2323]

It worked. Lot of thanks

[@abdullatifalothman4764]

in my situation, every time I hold the LCD to move it, the strange characters shows up, regardless of adding that line of code, which also slowed down the push button count :(
Anyone with similar issue? I will use another LCD to compare, then edit my comment

[@deeprex8099]

I also have the same issue.
did you compare with another LCD?

[@Enskkc]

I also have the same situation. I tried with a different 16x2 lcd screen and in it worked. But i am trying to find a solution to my lcd screen with the strange chinese character problem.

[@astrawally8448]

See my earlier comment, you have earthing issues and your logic levels are all over the shop, when you touch it, you exaggerate the problem. Even in this video, you can see at 0:16 the LCD board temporarily resets / under volts and dims and he is hanging onto the LED board (which is touching the LCD board).

[@chant2012]

awesome!

[@yashsrivastava81]

what if we are not using the I2C module and using LCD in 4/8bit mode, how to solve the weird characters problem ?

[@astrawally8448]

check your grounds

[@Antobarbunz]

unfortunately on my esp32 the problem is still facing :(

[@plageran]

thanks man

[@electrowashyelect9715]

How do one fix this in a c language programing

[@mumukshuneve180]

I still facing thi problem 😤 any can help me

[@rodolfovargas2621]

is this statment in the setup() zone? thanks.

[@plageran]

yip

[@ultraman9083]

Is it working on arduino uno r3?

[@user-sq4bv2ds3l]

yea I had the same question