请在上述keil代码的基础上添加代码，使得LCD屏幕亮起

为了使LCD屏幕亮起，需要添加一些额外的代码来初始化和配置LCD控制器。具体的实现取决于使用的LCD控制器型号和连接方式。

以下是一个简单的示例代码，用于控制与STM32H7xx单片机相连的基于SPI接口的LCD屏幕：

#include "stm32h7xx_hal.h"
#include "stm32h7xx_hal_gpio.h"
#include "stm32h7xx_hal_spi.h"

#define LCD_CS_PIN      GPIO_PIN_1
#define LCD_CS_PORT     GPIOB
#define LCD_DC_PIN      GPIO_PIN_2
#define LCD_DC_PORT     GPIOB
#define LCD_RST_PIN     GPIO_PIN_3
#define LCD_RST_PORT    GPIOB

SPI_HandleTypeDef hspi;
GPIO_InitTypeDef GPIO_InitStruct;

void LCD_init(void)
{
  /* Initialize SPI */
  hspi.Instance = SPI1;
  hspi.Init.Mode = SPI_MODE_MASTER;
  hspi.Init.Direction = SPI_DIRECTION_2LINES;
  hspi.Init.DataSize = SPI_DATASIZE_8BIT;
  hspi.Init.CLKPolarity = SPI_POLARITY_HIGH;
  hspi.Init.CLKPhase = SPI_PHASE_2EDGE;
  hspi.Init.NSS = SPI_NSS_SOFT;
  hspi.Init.BaudRatePrescaler = SPI_BAUDRATEPRESCALER_2;
  hspi.Init.FirstBit = SPI_FIRSTBIT_MSB;
  hspi.Init.TIMode = SPI_TIMODE_DISABLE;
  hspi.Init.CRCCalculation = SPI_CRCCALCULATION_DISABLE;
  hspi.Init.CRCPolynomial = 7;
  if (HAL_SPI_Init(&hspi) != HAL_OK)
  {
    Error_Handler();
  }

  /* Initialize GPIO pins */
  __HAL_RCC_GPIOB_CLK_ENABLE();
  GPIO_InitStruct.Pin = LCD_CS_PIN | LCD_DC_PIN | LCD_RST_PIN;
  GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_PP;
  GPIO_InitStruct.Pull = GPIO_NOPULL;
  GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_HIGH;
  HAL_GPIO_Init(LCD_CS_PORT, &GPIO_InitStruct);

  /* Reset LCD */
  HAL_GPIO_WritePin(LCD_RST_PORT, LCD_RST_PIN, GPIO_PIN_RESET);
  HAL_Delay(50);
  HAL_GPIO_WritePin(LCD_RST_PORT, LCD_RST_PIN, GPIO_PIN_SET);
  HAL_Delay(50);

  /* Configure LCD */
  LCD_WriteCommand(0x01); // software reset
  HAL_Delay(100);
  LCD_WriteCommand(0x11); // exit sleep
  HAL_Delay(100);
  LCD_WriteCommand(0x36); // memory data access control
  LCD_WriteData(0x08); // RGB
  LCD_WriteCommand(0x3A); // pixel format set
  LCD_WriteData(0x05); // 16-bit color
  LCD_WriteCommand(0x29); // display on
}

void LCD_WriteCommand(uint8_t cmd)
{
  HAL_GPIO_WritePin(LCD_DC_PORT, LCD_DC_PIN, GPIO_PIN_RESET);
  HAL_GPIO_WritePin(LCD_CS_PORT, LCD_CS_PIN, GPIO_PIN_RESET);
  HAL_SPI_Transmit(&hspi, &cmd, 1, HAL_MAX_DELAY);
  HAL_GPIO_WritePin(LCD_CS_PORT, LCD_CS_PIN, GPIO_PIN_SET);
}

void LCD_WriteData(uint8_t data)
{
  HAL_GPIO_WritePin(LCD_DC_PORT, LCD_DC_PIN, GPIO_PIN_SET);
  HAL_GPIO_WritePin(LCD_CS_PORT, LCD_CS_PIN, GPIO_PIN_RESET);
  HAL_SPI_Transmit(&hspi, &data, 1, HAL_MAX_DELAY);
  HAL_GPIO_WritePin(LCD_CS_PORT, LCD_CS_PIN, GPIO_PIN_SET);
}

int main(void)
{
  /* Initialize LCD */
  LCD_init();

  /* Infinite loop */
  while (1)
  {
    // Add your code here to control the LCD screen
  }
}

在这个例子中，我们使用了SPI接口来控制LCD屏幕，并初始化了SPI和GPIO外设。需要注意的是，这个例子中的LCD控制器型号和连接方式是未知的，因此需要根据实际情况进行修改。

在main函数中，我们只需要调用`LCD_init()`函数来初始化LCD控制器，然后在无限循环中添加代码来控制LCD屏幕即可。