mcufriend 2.8 tft lcd shield library brands

I have bought "MCUFRIEND" 2.8 tft touch lcd and controller printed on it shows "ILI9338". Example given in this library are not working except for the basic one and it don"t even work with touch examples. After searching on google found out that "MCUFRIEND_kbv" library for debug. When i run "diagnose_tft_support" it shows following output. Also added "Read reg" after first output. Please Help !!!

This note introduces a low-cost Thin Film Transistor (TFT) display to enhance the operation and usefulness of Liquid Crystal Display(LCD) devices. TFT technology controls the pixel element on the glass surface thereby greatly reducing image blurring and improving viewing angles.

The test board chosen for this exercise is the Elegoo Arduino UNO board from the corresponding Super Starter Kit. The kit already has several simple numeric and text displays. The TFT display may perhaps provide better ways to interact in applications.

The controller for the illustrated model of the TFT display is SSD1297.This information is important because the display (owing to its low cost and high popularity) has many different manufacturers who may not leverage the same controller instruction set. The specification of the controller in the coding exercises is examined in the Appendix section of this note.

Of course, the display can be mounted elsewhere and the pins connected to the Arduino directly or indirectly using, for example, a breadboard. Other components can then use the breadboard in lieu of a shield with custom connectors. Of course, without access to such anon-standard or readily available breadboard, it is impossible to illustrate this arrangement in this note.

The Examples folder for the library provides the starter files for the tests. If you are using a newer display you will need the updated libraries from the GitHub repository (see link in References below)and using the#definestatement to identify the display model.

The output from the diagnostic program, LCD_ID_reading.ino, is shown below:Read Registers on MCUFRIEND UNO shieldcontrollers either read as single 16-bite.g. the ID is at readReg(0)or as a sequence of 8-bit valuesin special locations (first is dummy)reg(0x0000) 97 97ID: ILI9320, ILI9325, ILI9335, ...reg(0x0004) 97 97 97 97Manufacturer IDreg(0x0009) 97 97 97 97 97Status Registerreg(0x000A) 97 97Get Power Modereg(0x000C) 97 97Get Pixel Formatreg(0x0061) 97 97RDID1 HX8347-Greg(0x0062) 97 97RDID2 HX8347-Greg(0x0063) 97 97RDID3 HX8347-Greg(0x0064) 97 97RDID1 HX8347-Areg(0x0065) 97 97RDID2 HX8347-Areg(0x0066) 97 97RDID3 HX8347-Areg(0x0067) 97 97RDID Himax HX8347-Areg(0x0070) 97 97Panel Himax HX8347-Areg(0x00A1) 97 97 97 97 97RD_DDB SSD1963reg(0x00B0) 97 97RGB Interface Signal Controlreg(0x00B4) 97 97Inversion Controlreg(0x00B6) 97 97 97 97 97Display Controlreg(0x00B7) 97 97Entry Mode Setreg(0x00BF) 97 97 97 97 97 97ILI9481, HX8357-Breg(0x00C0) 97 97 97 97 97 97 97 97 97Panel Controlreg(0x00C8) 97 97 97 97 97 97 97 97 97 97 97 97 97GAMMAreg(0x00CC) 97 97Panel Controlreg(0x00D0) 97 97 97Power Controlreg(0x00D2) 97 97 97 97 97NVM Readreg(0x00D3) 97 97 97 97ILI9341, ILI9488reg(0x00D4) 97 97 97 97Novatek IDreg(0x00DA) 97 97RDID1reg(0x00DB) 97 97RDID2reg(0x00DC) 97 97RDID3reg(0x00E0) 97 97 97 97 97 97 97 97 97 97 97 97 97 97 97 97GAMMA-Preg(0x00E1) 97 97 97 97 97 97 97 97 97 97 97 97 97 97 97 97GAMMA-Nreg(0x00EF) 97 97 97 97 97 97ILI9327reg(0x00F2) 97 97 97 97 97 97 97 97 97 97 97 97Adjust Control 2reg(0x00F6) 97 97 97 97Interface Control

Many thanks toDavidPrenticefor the display driver library and the guidance, support and advice during the tests for this display. I would have failed at the starting block without his generous assistance. He is an authority on the drivers for this class of displays.

I bought this to replace a similar 2.8" display which had developed problems with touch. I knew it was probably going to be a different controller so expected some mucking about. The existing setup is driven from an ESP32 board using the Arduino platform and the MCUFRIEND_kbv library. I"ve wired the display to the controller, so I"ve modified the library with my pinout.

First off the library didn"t read anything for the display controller model (0x00 returned). This is expected so relying on what is printed on the display pcb I hardcoded the 0x6809 value for the RM68090 controller. This didn"t work at all. To cut a (very) long story short, I tried every board value supported by the library and none worked perfectly (reversed colour and reversed display were the best I got). I tried rewriting the LM68090 initialisation code - no luck. Eventually I"ve ended up using 9329 code with some custom settings for the capabilities (I"ve called it 0x93FF). My version is on GitHub at jwrw/MCUFRIEND_kbv - at some point I"ll get it pulled into the original repository but didn"t like to as I"ve not really identified what controller this board is actually running.

The demos are developed based on the HAL library. Download the program, find the STM32 program file directory, and open the STM32 with four project folders: DisplayString, DrawGraphic, ShowImage, and Touchscreen.

I bought four MCU Friend 3.5″ TFT shields.  And, unfortunately, they have spiraled me into a deep, dark place trying to figure out how to use them.  The the documentation consists of a sticker on the antistatic bag, a picture of the shield with a list of 5 different possible LCD drivers, a pinout, and a block of code that supposedly represents the startup code.  The unfortunate part is that none of these have been exactly right – they all have errors.  This article is a description of the journey to figuring out how to use them.

It also has a picture which says the LCD has one of several different controllers (and after digging in I know for a fact that two of mine were made by Raydium and are not on the list)

And finally a table of pins.  Which is interesting as it lists 37 pins when the shield has no where near that number.  And it shows the shield as  16-bit interface which it isnt … and it shows some LEDs which aren’t there either.

I bought 4 different shields.  One came broken.  The other three are all different.  When you look at the boards there are two visibly different configurations

The first thing I did was try to use the MCUFRIEND_kbv library to see if the screens worked.  The first board identified as ID=0x9403 and did not work.  Apparently, the tool just spits out the ID if it doesn’t know it, which it did not.

One of the boards identified as ID=0x6814 worked perfectly, and one had a blue cast to all of the screens.  The crazy part is the two boards that identified as ID=0x6814 had different PCBs.  According to the comments in the MCUFRIEND_kbv.cpp ID=0x6814 is an RM68140 and ID=9403 is unknown.

Next, I started down the path of trying to figure out what the controllers were by using register reads.  David Prentice (the guy who wrote/maintains the MCU Friend_kbv Arduino library) has an absolute ton of responses on the Arduino forum trying to help people figure out what their shield is.  He asks them to post the register report from his example program LCD_ID_readnew which is included as an example in the library.

When you look at these LCD controllers they all have some variant of “Read ID” which responds with 1-6 bytes.  The basic idea of this program is to look at what bytes are returned to try to identify the controller.  Here is an example of what I got when I ran the LCD_ID_readnew program on my shields:

The key thing to see in this output is the register 0x04 which says 54,80,66 which identifies this as a Raydium RM68140 LCD controller.  Here is a snapshot from the data sheet.

After digging some more, I decided that it is super ugly out there, as you find that there are a significant number of LCD controllers that are clones, copies, pirated etc… and that they all present themselves differently.  And, in hindsight I think that this is the reason that my ILI9341 from the previous article doesnt quite work correctly.

The next thing that I did was try out the startup code that MCUFriend_kbv generates.  I used the same technique from PSoC 6 + Segger EmWin + MCUFriend 2.4″ Part 1 and spit out the startup bytes.  Here they are:

At this point I have spent a frightening amount of time figuring out how these screens work.  Although it has been a good learning experience, I have generally decided that using unknown displays from China with LCD drivers of questionable origin is not worth the pain of trying to sort out the interface.  Beyond that:

Im new to Arduino myself but i do have the same screen which works perfect,your problem is probably that the TFT shield is shorting off the top off the arduino usb put something non conductive there and reset. if your still having trouble, try removing the shield and watch each pin as you insert it to make sure they are all inserted in the correct pins, LCD_02 should be in Dig pin 2.