stm32f429 tft lcd ili9341 brands

STM32F429 has also LTDC driver for LCD like that, but this driver we will use later. For now we will use SPI for driving in serial mode and some other pins for controlling.

Remember: This library can also be used, if you are not using STM32F429 Discovery. It can be used in previous STM32F4 Discovery board. All pins can be changed in defines.h file which is included in project.

1. use 5v to led pin, 3.3v to vcc and 1k / 1.5k resistor voltage dividers to get it to work. 1k resistor in series from Ar-duino to tft logic pin, 1.5k from tft pin to ground.

The LCD I am using is a 2.8″ TFT LCD with SPI communication. I also have another 16-bit Parallel TFT LCD but it will be another story for another time. For this post, let’s focus on how to display what you want on the 2.8″ LCD. You can find all details about this LCD from this page:http://www.lcdwiki.com/2.8inch_SPI_Module_ILI9341_SKU:MSP2807

First thing first, this LCD use SPI as the main communication protocol with your MCU. For STM32 users, HAL Library has already implemented this protocol which makes this project easier for us. But, a little knowledge about this protocol does not hurt anyone. SPI is short for Serial Peripheral Interface which, aside from two data lines, also has a clock line and select lines to choose between devices you want to communicate with.

This LCD uses ILI9341 as a single-chip SOC driver for a display with a resolution of 240×320. More details can be found in the official document of ILI9341. But the most important thing is that we have to establish astart sequencein order for this LCD to work. The “start sequence” includes many other sequences which are also defined in the datasheet. Each sequence starts when you send a command to ILI9341 and then some parameters to follow up. This sequence is applied for all communication between MCU and ILI9341.

For this project, I recommend using theSystem Workbench for STM32for coding and building the code. After installing and open the program, go to the source code you have just downloaded and double click the.cprojectfile. It will automatically be open in your IDE. Then build the program by right click on the folder you just open (TFTLCD) and chooseBuild Project. Wait for it to finish and upload it to the board by right clicking the folder, choose Run As and then clickAc6 STM32C/C++ Application. And that’s it for running the example.

The most important library for this project is obviously the ILI9341_Driver. This driver is built from the provided source code in the lcdwiki.com page. I only choose the part that we need to use the most in many applications like writing string, displaying image and drawing symbols. Another library from the wiki page is the TOUCH library. Most of the libraries I got from the Internet were not working properly due to some adjustments to the original one.

To draw symbols or even display images, we need a “byte array” of that image or symbol. As an illustration, to display an image from a game called Transistor, I have a “byte array” of that image stored in a file named transistor.h. You can find this file in the link below. Then, I draw each pixel from the image to the LCD by adding the code in the Display_Picture() function in the Display folder.void Display_Picture()

You can refer to the examples under STM32CubeF4 package to see their structure and get inspired from them to configure your files: STM32Cube_FW_F4_V1.21.0\Projects\STM32F429I-Discovery\Applications\STemWin

IMPORTANT The touchscreen has a maximum frequency of 2MHz, which is probably slower than you want your TFT SPI clock. So in the routine that reads touch coordinates (ili9341_touch_pressed_t ili9341_touch_coordinate(ili9341_t *,uint16_t *,uint16_t *) in ILI9341/ili9341.c), make sure to adjust the lines that modify the SPI clock so that your baud rate is less than 2MHz before communicating with the touchscreen (e.g. MODIFY_REG(lcd->spi_hal->Instance->CR1, SPI_CR1_BR, SPI_BAUDRATEPRESCALER_128)), and then restored to whatever setting you use here immedaitely afterwards. See the comments in that source file for both locations.

If using the touchscreen, you will probably want to set Hardware NSSP=Disabled (slave/chip-select) in favor of a software implementation, since you will need one signal for the TFT and a separate one for the touchscreen. Any two unused GPIO digital output pins will work.

If using the touchscreen, override the EXTI callback (void HAL_GPIO_EXTI_Callback(uint16_t)) somewhere in your application code and call ili9341_touch_interrupt(ili9341_t *) from inside that callback.