Author Topic: Help on making a display to work  (Read 671 times)

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Offline vaualbus

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Help on making a display to work
« on: January 15, 2021, 09:26:26 pm »
For a university project I have to use the following display module: 4DLCD-35480320-CTP. I have already write the code to init it, following the one in the datasheet but I really can't understand why it does not work at all. The only thing I got is a white screen. The screen is wired correctly. I'm using an STM32L496 micro running at 80Mhz.
Below I attach the code I wrote please if any can review and try to figured out the problem I would be so gratefully I really run out of idea and I have already buy a new one in case mine was broke.
Below I attach two version I made both are not working. I'm also attaching  the datasheet
I know it's not good to ask for "code" but this time I really have no idea where to go  |O :-// :-//
This init code will be go into a larger code base but I wanna modularize it into a single header file.
Best regards,
« Last Edit: January 15, 2021, 09:29:32 pm by vaualbus »

Offline zulunation

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Re: Help on making a display to work
« Reply #1 on: January 16, 2021, 08:25:04 am »
You should follow general steps working with any devices connected to microcontrollers.
First check if you can read id of the lcd screen. If so it is likely not broken.
If you can't read id. Check schematics and timing diagram with logic analyzer.
If you able to read id. Read carefully datasheet on initialization sequence. AN check timing diagram again.

Offline madires

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Re: Help on making a display to work
« Reply #2 on: January 16, 2021, 04:45:39 pm »
Several LCD driver libs support the ILI9488. Check out what they do and compare that with your code. Another example is the ILI9488 driver for the Transistortester m-firmware (ATmega) I've written (

Offline vaualbus

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Re: Help on making a display to work
« Reply #3 on: May 01, 2021, 10:44:55 pm »
You wanna now what had happened since?
The datasheet was wrong and the SCK was swapped with the DC pin in the provided schematics so yeah I guess there were reasons for which it won't work....
The story is even silly... Because the original datasheet present on the mouser/digikey/ecc have the pin wrong in all the places.
The updated datasheet that I obtained,  when I ask for support, had in the connector schematics the correct pinout but the default schematics was still wrong.
So basically I was doomed to fail at the start.  |O |O |O |O |O |O  |O |O |O |O |O |O
Once I found the problem, and they update the datasheet than, and a new board was made it worked first try  :-// :-//
At least as I thought the code was right ahah

It's so funny what happens to me  :-DD

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