LCD TFT problem with display

Other Hardware Displays
1

Hey guys

Im very new to arduino stuff, but i bought a set from open smart TFT LCD 3.5

I downloaded the ST7793 library plus extras, but i only get white screen.

On the board says ST7793

i ran diagnose_tft from mcufriend and:

20:27:53.902 -> Diagnose whether this controller is supported
20:27:53.948 -> There are FAQs in extras/mcufriend_how_to.txt
20:27:53.994 ->
20:27:53.994 -> tft.readID() finds: ID = 0x5393
20:27:54.041 ->
20:27:54.041 -> MCUFRIEND_kbv version: 2.9.9
20:27:54.041 ->
20:27:54.278 ->
20:27:54.278 -> This ID is not supported
20:27:54.278 -> look up ID in extras/mcufriend_how_to.txt
20:27:54.322 -> you may need to edit MCUFRIEND_kbv.cpp
20:27:54.369 -> to enable support for this ID
20:27:54.369 -> e.g. #define SUPPORT_8347D
20:27:54.416 ->
20:27:54.416 -> New controllers appear on Ebay often
20:27:54.463 -> If your ID is not supported
20:27:54.510 -> run LCD_ID_readreg.ino from examples/
20:27:54.510 -> Copy-Paste the output from the Serial Terminal
20:27:54.603 -> to a message in Displays topic on Arduino Forum
20:27:54.603 -> or to Issues on GitHub
20:27:54.649 ->
20:27:54.649 -> Note that OPEN-SMART boards have diff pinout
20:27:54.697 -> Edit the pin defines in LCD_ID_readreg to match
20:27:54.743 -> Edit mcufiend_shield.h for USE_SPECIAL
20:27:54.791 -> Edit mcufiend_special.h for USE_OPENSMART_SHIELD_PINOUT

it seems a different id not 7793

any thoughts?
thanks for the help

2

It may be more helpful if you could post a pic of both sides of the LCD or at least a link to the product you purchased.

3

Welcome lipeter

your topic has been moved to a more suitable location on the forum. Installation and Troubleshooting is not for problems with (nor for advice on) your project :wink: See About the Installation & Troubleshooting category.

4

Please post a link to the actual board that you have bought. e.g. Ebay sale page.
Have you bought the red "OPEN-SMART UNO R3 AIR" board to go with it ?

I have the bare 3.3V ST7793 board from Open-Smart.

David.

5

https://www.aliexpress.com/snapshot/0.html?spm=a2g0s.buyer_waiting_review.0.0.651c6c1bbEMk1N&orderId=8151009812106129&productId=32964204802

This is what i bought .

I will upload front and back of lcd

6

Yes i did buy that one, at least, its that description

7

Your link fails. Just click on your order history. Click on the item you bought. Post the URL of the item page.

Otherwise just describe in words.
e.g. red display pcb with 16x1 header.
e.g. red "OPEN-SMART UNO R3 AIR" board

David.

8

image
image1280×768 245 KB

i

9

Here is the link, dam AliExpress APP doesnt like to share HTML.

10

Thanks for the link. That is exactly the same as my display + AIR.

Make sure that you switch GPIO to 3V via toggle next to USB on AIR board.

  1. Install MCUFRIEND_kbv via IDE Library Manager.
  2. Edit utility/mcufriend_shield.h for USE_SPECIAL
  3. Edit utility/mcufriend_special.h for USE_OPENSMART_SHIELD_PINOUT_UNO

You will find that PORTRAIT_REV and LANDSCAPE_REV are wrong in v2.9.9-Release. This is fixed in the current Beta.

12

I will try that kind sir

Thank you

13

I have just released MCUFRIEND_kbv v3.0.0-Release which you should see in the Library Manager later today.

You will still need to edit for the "SPECIAL" to match your AIR board.

14

ok, ive done so far as edit /mcufriend_special.h

couple of doubts here

on the board it says st7793 i assume is 0x7793 as id.
but the id in serial monitor says diferent.
tft.readID() finds: ID = 0x5393

wich and where should i place them in special?

again thanks for your time

15

Read the how_to file. You will find it at
C:\Users\ ... \Documents\Arduino\libraries\Mcufriend_kbv\extras\mcufriend_how_to.txt

You edit library files i.e.
C:\Users\ ... \Documents\Arduino\libraries\Mcufriend_kbv\utility\mcufriend_special.h
from this

//#define USE_OPENSMART_SHIELD_PINOUT_UNO

to this

#define USE_OPENSMART_SHIELD_PINOUT_UNO

and similarly with the first line in
C:\Users\ ... \Documents\Arduino\libraries\Mcufriend_kbv\utility\mcufriend_shield.h

Yes, I know it is a bit fiddly. Hey-ho, the library was designed for regular Uno Shields.

Oh, the updated v3.0.0-Release has appeared on the Library Manager now.

David.

16

i got it to work.

was unware that libraries also went to documents, so had a conflict of mcufriends

So i did a clean slate install on the sellers libs and i got it to work.
all started because i tried adafruit and mcufriend directly from update.
big no no with chinese boards, they seem to like their own code.

i apreciate the help :slight_smile:

17

Chinese companies just hack obsolete libraries.

I would be much happier if they cooperated with library authors.
Then we could publish code that promotes their hardware.

The worst part of the "hacked library" is that they retain the original name.
And since they are not supported by the Library Manager they might get installed anywhere !!

Open-Smart seem to be quite a nice company.
LCDWIKI with their badly spelled libraries are very bad news.

David.

18

Believe me mr David, if i knew, i would have bought a more commun board, like i said, im new to this, and offtopic its for even larger project for hydroponics.

Thanks once again for your time

19

The ST7793 works well with the 3.3V AIR board.

And the AIR board is very useful for controlling 3.3V sensors, displays, ...
Much easier than wiring up external level shifters on a 5V Uno.

David.

20

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