stm32 tft lcd interface quotation

The STM32 LTDC has a peripheral called LTDC LCD TFT Display Controllerwhichprovides a digital parallel interface(DPI) for a variety of LCD and TFT panels. It sends RGB data in parallel to the display and generates signals for horizontal and vertical synchronization (HSYNC, VSYNC), as well as pixel clock (PCLK) and not data enable (DE) signals:

In this example I use the display on the STM32F429-Discovery board, which is driven by the ILI9341 display controller. The ILI9341 can drive a QVGA (Quarter VGA) 240×320 262,144 colors LCD display. The controller can be configured via SPI (or parallel interface, depending on the panel settings) to use a digital parallel 18 bit RGB interface (since only 6 lines per color channel are wired on the board to the LTDC). Since the display pixel format is less than 8 bit per channel (RGB666 in this case), the RGB display data lines are connected to the most significant bits of the LTDC controller RGB data lines:

Before enabling the LTDC we must configure the clock system. The LTDC uses a specific clock LCD_CLOCK to generate the pixel clock signal and it must be configured and enabled during the system initialization phase:

To display an image we must convert an image file to an array (possibly a const one, so it can be stored in flash memory) of bytes. To do this I used LCD image converter, a simple but powerful application that can convert a file to a variety of different pixel formats:

In this example the framebuffers have a RGB888 color depth and for a 240×320 display that makes 225 KiB of memory for each buffer (3 bytes per pixel x 240 x 320 pixels) so they must be stored in external SRAM (the STM32F429I-DISCOVERY has a 64Mbit external SRAM so we’re good). The FMC Flexible Memory Controller has to be initialized and the address of the two frame buffers has to be configured. Drawing on the framebuffer is a matter of writing the right bytes in order to change the color. Once all pixels are drawn (bytes are written) the buffers are switched and the code can draw the next frame:

According to the Setup, the LCD_D2 is connected to the PA15. So if I want to write the DATA to the LCD_D2 pin, first I will select the 2nd bit of the data (d & (1<<2)), and than shift this by 13 using <<13. This will be like adding 2 with 13 to make a total of 15, and that’s where the LCD_D2 is connected to.

Similarly, LCD_D7 is connected to PA5. So to write the data, first we will select the 7th bit of the data (d & (1<<7)), and this time shift it RIGHT by 2 (>>2). This is like subtracting 7-2=5. And that’s where, the D7 is connected to.

The process here remains the same. Except, we have to first select the GPIO Pin, and than shift it according to the position of the LCD Pin, that it is connected to. In the function above, we are first selecting the PB0 pin, and as it is connected to LCD_D0, we don’t need to shift it anywhere. Same for the PB1 also.

Next, we are selecting PA15, and as this one is connected to the LCD_D2, we need to shift it by 13 to the right ( >>13). This process continues for all other pins too.

After all the Pins work is done, we still need to select the delays according to our clock frequency. As I am using STM32F103C8 at72 MHz, I am going to uncomment the respective code as shown below.

Therefore, it may be more advantageous to use a driver chip, to avoid a lot of setup with external memory. Since it"s not just a software issue, but also the hardware doesn"t have all the support to perform the direct operation with the TFT display (it doesn"t accept STN either).

first thanks for your response..i am new for TFT lcd.I attached my details.If u got any idea tell me.i am facing problem in 10" TFT lcd interfacing.problem is lcd back light is flikering.i attached a file see that.

1)my TFT pannel WY101ML308HS18A is a Active matrix TFT panels and it can support up to 24-bit bus.my controller is lpc1788 so it has inbuild lcd controller and it can support .

2)the controller has a parallel bit interface, the panel has a LVDS interface.But here i am using a SN75LVDS83B to convert the 24 bit parallel data into LVDS format..and sending to TFT lcd pannel via 4 bus.

4)i thought the problem is in lcd initialization.i need the exact value for hsync and vsync front porch,back porch ,horizontal and vertical pulse width value.

lcd_14arial_writestr(a,b,"WELCOME","B",RED,WHITE);// Its a function for displaying 14 Arial font character. a=horizontal location,b=vertical location,welcome =character should display in TFT lcd(accessing from ASCII Library), red=character color,white=screen border color.

I am working on STM32F103ZT6 and with SSD1963. I have connected 480X272 and 320X240 LCD’s. I am initializing SSD1963 with the Init Commands on same pins as you use, but in GPIO mode & not in FSMC mode. The Clock Freq from Crystal is 8MHz and in STM32 acitvating PLL is made to 72MHz. So, Clk Freq for SSD1963 is 8MHz. Hope we should configure the PLL in SSD1963. So below is my Initialisation Sequence details.

3. Onboard level conversion chip, can be applied to cpu such as 5v MCU, also applicable to low voltage cpu such as stm32, no need for external conversion

The ARM® Cortex®-M4-based STM32F4 series of MCUs leverages STMicroelectronics" NVM technology and ST’s ART Accelerator™ to reach the industry’s highest benchmark scores for Cortex-M-based microcontrollers with up to 225 DMIPS / 608 CoreMark executing from Flash memory at up to 180 MHz operating frequency.

he STM32F4 series consists of 7 lines of digital signal controllers (DSC), a perfect symbiosis of the real-time control capabilities of an MCU and the signal processing performance of a DSP:

STM32F411 – 100 MHz CPU/125 DMIPS, outstanding power efficiency with large SRAM and new smart DMA optimizing power consumption for data batching (Dynamic Efficiency Line with Batch Acquisition Mode)

STM32F427/437 – 180 MHz CPU/225 DMIPS, up to 2 Mbytes of dual-bank Flash with SDRAM interface, Chrom-ART Accelerator™, serial audio interface, more performance and lower static power consumption

STM32F469/479 – 180 MHz CPU/225 DMIPS, up to 2 Mbytes of dual-bank Flash with SDRAM and QSPI interface, Chrom-ART Accelerator™, LCD-TFT controller and MPI-DSI interface

EasyTFT board is a perfect choice for users or mikroElektronika boards who want to upgrade their GLCD with TFT display. It features connector compatible with GLCD 128x64 connectors, as well as touch panel connectors. Board also contains TFT Color Display MI0283QT-9A with 320x240px resolution, which is driven by