Checking a TFT lcd driver is very messy thing especially if its a Chinese manufactured TFT. TFT’s that are supplied by Chinese manufactures are cheap and every body loves to purchase them since they are cheap,but people are unaware of the problems that comes in future when finding the datasheet or specs of the particular TFT they purchased. Chinese manufactures did not supply datasheet of TFT or its driver. The only thing they do is writes about the TFT driver their lcd’s are using on their websites. I also get in trouble when i started with TFT’s because i also purchased a cheap one from aliexpress.com. After so many trials i succeeded in identifying the driver and initializing it. Now i though to write a routine that can identify the driver.
I wrote a simple Arduino Sketch that can easily and correctly identify the TFT Lcd driver. I checked it on 2.4, 3.2 and 3.8 inch 8-bit TFT lcd and it is identifying the drivers correctly. The drivers which i successfully recognized are ILI9325, ILI9328, ILI9341, ILI9335, ST7783, ST7781 and ST7787. It can also recognize other drivers such as ML9863A, ML9480 and ML9445 but i don’t have tft’s that are using this drivers.
Basic idea
The basic idea behind reading the driver is reading the device ID. Since all the drivers have their ID’s present in their register no 0x00, so what i do is read this register and identify which driver tft is using. Reading the register is also a complex task, but i have gone through it many times and i am well aware of how to read register. A simple timing diagram from ST7781 driver explains all. I am using tft in 8-bit interface so i uploaded timing diagram of 8-bit parallel interface. The diagram below is taken from datasheet of ST7781 tft lcd driver.
Timing diagrams reading registers
The most complex tft i came across is from a Chinese manufacturer “mcufriend”. mcufriend website says that they use ILI9341 and ILI9325 drivers for their tft’s. But what i found is strange their tft’s are using ST7781 driver(Device ID=7783). This is really a mesh. I have their 2.4 inch tft which according to their website is using ILI9341 driver but i found ST7783 driver(Device ID=7783). The tft i have is shown below.
Arduino code
I am using Arduino uno to read driver. I inserted my lcd on arduino uno and read the driver. After reading driver i am printing its number on Serial Monitor.
Note: On serial monitor driver number will be displayed like if your lcd is using ST7783 controller than on serial monitor 7783 will be displayed or if tft is using ILI9341 than on 9341 will be displayed.
Note: On serial monitor driver number will be displayed like if your lcd is using ST7783 controller than on serial monitor 7783 will be displayed or if tft is using ILI9341 than on 9341 will be displayed.
The code works on Arduino uno perfectly but if you are using any other board, than just change the pin numbers according to the board that you are using also check out for the Ports D and B. TFT Data Pin D0 is connected to Port-B Pin#0 and D1 is connected to Port-B Pin#1. TFT Data Pins D2 to D7 are connected to Port-D Pins 2,3,4,5,6,7. So if you are using Arduino mega than check for the Ports D and B and Make connections according to them. Arduino mega is working on ATmega2560 or ATmega1280 Microcontroller and Arduino uno is working on ATmega328p Microcontroller so both platforms have ports on different locations on arduino board so first check them and then make connections. The same process applies to all Arduino boards.
Future Work:
If any one want to contribute than help me design a universal library for all the arduino boards. Waiting for reply from beneficiaries.
If any one want to contribute than help me design a universal library for all the arduino boards. Waiting for reply from beneficiaries.
Download the project files, folder contains Project .ino file. If you have any questions feel free to ask me. Just write your queries below in the comments section.
Filed Under: Arduino, Microcontroller Projects
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