Configure STM32 SPI DMA for ILI9341 TFT Display with 16-bit Color Depth

Introduction

The STM32 microcontroller, when paired with a DMA (Direct Memory Access) controller, can efficiently handle SPI communication for driving TFT displays like the ILI9341. This tutorial will guide you through the steps necessary to configure SPI with DMA for rendering 16-bit color depth images on the ILI9341 display.

Prerequisites

• Basic knowledge of C programming
• STM32 development board (e.g., STM32F4, STM32F1)
• ILI9341 TFT display module
• STM32CubeIDE or similar development environment
• Familiarity with SPI and DMA concepts

Parts/Tools

• STM32 Microcontroller
• ILI9341 TFT Display
• Jumper wires
• Breadboard (optional)
• USB to UART converter (for debugging, optional)

Steps

1. Set Up Hardware
   • Connect the ILI9341 display to your STM32 board using the following pin configuration:

     
         STM32 Pin  | ILI9341 Pin
         ------------|-------------
         SPI_SCK    | SCK
         SPI_MOSI   | SDA
         SPI_CS     | CS
         SPI_DC     | DC
         RESET      | RESET
                     

2. Configure STM32CubeMX
   • Open STM32CubeMX and create a new project for your STM32 board.
   • Enable the SPI peripheral:
     1. In the “Pinout & Configuration” tab, select the SPI interface.
     2. Set the mode to “Master” and configure the parameters according to the ILI9341 specifications (e.g., clock polarity and phase).
   • Enable DMA for the SPI:
     1. In the “Configuration” tab, select “DMA Settings” and add a new DMA stream.
     2. Set the direction to “Memory-to-peripheral”.
   • Configure other settings as needed and generate the code.
3. Implement SPI Initialization Code
   • In the generated code, navigate to the `stm32fxxx_hal_msp.c` and implement the following:

     
     void HAL_SPI_MspInit(SPI_HandleTypeDef* hspi) {
         // Enable the SPI clock
         __HAL_RCC_SPI1_CLK_ENABLE();
         
         // Configure SPI GPIO pins
         GPIO_InitTypeDef GPIO_InitStruct = {0};
         GPIO_InitStruct.Pin = GPIO_PIN_5 | GPIO_PIN_6 | GPIO_PIN_7; // SCK, MOSI, MISO
         GPIO_InitStruct.Mode = GPIO_MODE_AF_PP; 
         GPIO_InitStruct.Pull = GPIO_NOPULL;
         GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_VERY_HIGH;
         HAL_GPIO_Init(GPIOA, &GPIO_InitStruct);
     }
                     

4. Initialize the ILI9341 Display
   • Add a function to send commands to the ILI9341:

     
     void ILI9341_SendCommand(uint8_t cmd) {
         HAL_GPIO_WritePin(GPIOA, GPIO_PIN_CS, GPIO_PIN_RESET); // CS Low
         HAL_GPIO_WritePin(GPIOA, GPIO_PIN_DC, GPIO_PIN_RESET); // Command mode
         HAL_SPI_Transmit(&hspi1, &cmd, 1, HAL_MAX_DELAY);
         HAL_GPIO_WritePin(GPIOA, GPIO_PIN_CS, GPIO_PIN_SET); // CS High
     }
                     

   • Initialize the display in your main function:

     
     void ILI9341_Init() {
         ILI9341_SendCommand(0x01); // Software reset
         HAL_Delay(150);
         // Additional initialization commands...
     }
                     

5. Send Data Using SPI with DMA
   • Prepare a buffer for pixel data:

     
     uint16_t buffer[320 * 240]; // Example buffer for 320x240 display
     // Fill buffer with 16-bit color data
                     

   • Implement the DMA transfer function:

     
     void ILI9341_SendData(uint16_t* data, uint16_t size) {
         HAL_SPI_Transmit_DMA(&hspi1, (uint8_t*)data, size * sizeof(uint16_t));
     }
                     

Troubleshooting

• No Display Output:
  • Check the wiring and connections to the ILI9341.
  • Ensure the SPI settings in CubeMX match the display requirements.
• Data Corruption:
  • Verify that the buffer is properly filled with valid color data.
  • Check the DMA configuration and ensure it is properly linked to the SPI peripheral.

Conclusion

By following these steps, you should have successfully configured SPI communication using DMA for your ILI9341 TFT display with 16-bit color depth rendering. This setup allows for more efficient rendering and smoother graphics. Experiment with different images and display settings to fully utilize your TFT display capabilities!