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Using MCU Xpress to develop rt1060 (1) -- drive RGB interface LCD

2022-04-21 19:11:00 【EEHAHA】

One 、 development environment

1.TencentOS Internet of things development kit ,MCU by RT1060

2.IDE：MCUXpresso v11.4.1

3. The screen is light snow 4.3 " IPS The screen ,RGB888 Interface

Two 、 Use MCUXpreso Configuration tools

1. utilize IDE The function of , from SDK Import routines from hello_world, As the basic framework of the program .

2. open IDE Peripheral page in the configuration tool .

3. Add... In the left peripheral LCDIF, Turn on the peripherals LCDIF Set up .

RGB mode initialization Part is configured by the user according to the parameters of the screen , Including screen pixel frame rate and other parameters .

You can see it on the way IDE Reported a warning. Because it is calculated according to parameters such as pixel points and frame rate LCD The controller clock is different from the actual clock , The actual clock is determined by the hardware , Cannot be configured as like as two peas designed. , therefore IDE A warning message is generated . This warning message does not affect the normal operation of the screen . As can also be seen in the figure, the frame rate we designed is 60Hz, But according to the current clock configuration , The actual frame rate should be 64Hz.

Lower part Signals polarity yes LCD Polarity of control signal , Set according to the interface of the screen .

It is worth noting that ,LCD data bus namely LCD In the format of data bus ,RGB888 There are two formats , One is unpackaged , Occupy 32bits The format of , The other is to abandon the highest 8 Bit 24bits Format . This format must correspond to the program written by yourself , Otherwise, an error will appear on the screen .

LCDIF_Buffer Is a video memory variable , The tool will open up a memory space with this name . Users can modify LCDIF_Buffer To display what you want .

Remember to check that start RGB mode, Otherwise, you need to add open in the user program RGB The code for the pattern .

The configuration content at the bottom is the same as LCD Related to the interruption of the controller . In this program , I turned on the interrupt of frame transmission completion .LCDIF_IRQn Is the interrupt function we need to rewrite .

After the above configuration , Click update code , It will be added in the project directory peripheral.c and .h file , In which LCD Initialization work .

3、 ... and 、 Program code

open peripheral Source files and header files , Let's see what the official configuration tool has done for us .（ Only part of the code is shown in the article ）

//peripheral.c

const elcdif_rgb_mode_config_t LCDIF_rgbConfig = {
  .panelWidth = LCDIF_PANEL_WIDTH,
  .panelHeight = LCDIF_PANEL_HEIGHT,
  .hsw = 30U,
  .hfp = 210U,
  .hbp = 30U,
  .vsw = 4U,
  .vfp = 4U,
  .vbp = 4U,
  .polarityFlags = (kELCDIF_VsyncActiveLow | kELCDIF_HsyncActiveLow | kELCDIF_DataEnableActiveHigh | kELCDIF_DriveDataOnRisingClkEdge),
  .bufferAddr = (uint32_t) LCDIF_Buffer[0],
  .pixelFormat = kELCDIF_PixelFormatXRGB8888,
  .dataBus = kELCDIF_DataBus24Bit
};
/* RGB buffer */
AT_NONCACHEABLE_SECTION_ALIGN(uint32_t LCDIF_Buffer[2][LCDIF_PANEL_HEIGHT][LCDIF_PANEL_WIDTH], LCDIF_RGB_BUFFER_ALIGN);

This part is to build LCD Setting parameters of controller , Is the pixel we filled in the configuration tool before 、 Frame rate and other settings .

The bottom line of code is to apply for a section of memory space LCDIF_Buffer, For video storage . For the specific implementation method, please refer to the wild fire in the resources of this article RT1052 Development board tutorial .

//peripheral.c


static void LCDIF_init(void) {
  /* RGB mode initialization */
  ELCDIF_RgbModeInit(LCDIF_PERIPHERAL, &LCDIF_rgbConfig);
  /* Enable interrupts */
  ELCDIF_EnableInterrupts(LCDIF_PERIPHERAL, (kELCDIF_CurFrameDoneInterruptEnable));
  /* Enable interrupt LCDIF_IRQn request in the NVIC. */
  EnableIRQ(LCDIF_LCDIF_IRQN);
  /* RGB mode start */
  ELCDIF_RgbModeStart(LCDIF_PERIPHERAL);
}

/***********************************************************************************************************************
 * Initialization functions
 **********************************************************************************************************************/
void BOARD_InitPeripherals(void)
{
  /* Initialize components */
  LCDIF_init();
}

/***********************************************************************************************************************
 * BOARD_InitBootPeripherals function
 **********************************************************************************************************************/
void BOARD_InitBootPeripherals(void)
{
  BOARD_InitPeripherals();
}

Just look at the names of these functions , This code is for peripherals LCD Initialization and interrupt configuration of controller , And layers of packaging . We are main The last middle note in the function is called. BOARD_InitBootPeripheraals Function to complete the initialization of peripherals .

From the above code analysis , The configuration tool has helped us LCD The controller is set , The user only needs to call one function , Reduced code development . After that, the user can choose according to their own needs , Just design the code at the application level .

I wrote a piece of code , Let the screen alternate between blue and white . It mainly refers to the wild fire RT1052 The program in the tutorial .

//mylcd.c

#include "my_rd_lcd.h"
#include "fsl_common.h"
#include "stdint.h"
#include "fsl_debug_console.h"
#define MY_RD_LCD_TEST 1
// Create video memory space 
// It has also passed IDE The built-in design tools are set up 
//AT_NONCACHEABLE_SECTION_ALIGN(pixel_t
//s_psBufferLcd[2][LCD_PIXEL_HEIGHT][LCD_PIXEL_WIDTH], FRAME_BUFFER_ALIGN);

static uint32_t current_frame_buff = (uint32_t)LCDIF_Buffer[0];

static pixel_t current_text_color = CL_WHITE;
static pixel_t current_back_color = CL_BLUE;

static uint8_t s_frameDone = 1;
static uint8_t frameBufferIndex = 0;
/*  Frame counter  */
static volatile uint32_t s_frame_count = 0;
static void put_pixel(uint16_t x, uint16_t y, pixel_t color)
{
	if((x < LCDIF_PANEL_WIDTH) && (y < LCDIF_PANEL_HEIGHT))
	{
		//LCDIF_Buffer[0][y][x] = color;
		*(pixel_t*)(current_frame_buff + LCD_BPP*(x + (LCDIF_PANEL_WIDTH * y))) = color;
	}
}

void LCDIF_LCDIF_IRQHANDLER(void)
{
	volatile uint32_t intStatus;
	intStatus = ELCDIF_GetInterruptStatus(LCDIF);
	ELCDIF_ClearInterruptStatus(LCDIF, intStatus);
	if (intStatus & kELCDIF_CurFrameDone)
	{
		s_frameDone = 1;
		s_frame_count++;
	}
}

Four 、 Running results

This program allows the screen to display a frame of data , Show next frame now , And pass systick Interrupt timing , Calculate the refresh frame rate of the screen , You can achieve 80 The frame rate of .

There is also a problem here ,LCDIF The default clock source is selected PLL3 Produced , It is found that LCD Your clock frequency is wrong , Change it to PLL2 after , Is the correct clock frequency , Yet to be explored .

utilize MCUXpresso Users can easily develop NXP MCU program , Especially in use RT1060 This kind of cross-border MCU More complex peripherals in . Using the official configuration tool is more helpful for users to understand the functions of peripherals , You don't have to change the code line by line to the official routine , Speed up development , Reduce the probability of error .

Used to KEIL Development ARM after , Use this based on eclipse Of IDE I still feel a little uncomfortable . But because it's NXP Officially designed , More suitable for developing NXP The single chip computer of , And provides a lot of KEIL There is no more convenient tool for development . And this kind of IDE It's completely free , For personal enthusiasts , It is still necessary to learn and use MCUXpresso To develop the single chip microcomputer project .