【STM32F411Nucleo测评】驱动 1.3 寸 LCD 屏幕

pomin

【STM32F411Nucleo测评】驱动 1.3 寸 LCD 屏幕 [复制链接]

<i class="pstatus"> 本帖最后由 pomin 于 2024-2-28 09:09 编辑 </i>

> 这块 Nucleo-F411 板子支持 Arduino 的接口，得益于F411的丰富资源，当然可以跑屏幕应用了，正好手上有块空闲屏幕，F411 板没收到时就画了一个接口拓展板子，外接屏幕、按键、RS485 接口

## 硬件原理图

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## 3D 仿真图

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## 实物图

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## 点屏

### 确定驱动芯片

这块屏幕是中景园的，驱动是 ST7789，下载下来他们提供的资料，其中只需要他们提供的屏幕初始化序列即可，因为例程较多的是标准库，我是使用的 CubeMX 生成的 HAL 来开发，提供的初始化序列如下

```c
//************* Start Initial Sequence **********// 
LCD_WR_REG(0x36);
if(USE_HORIZONTAL==0)LCD_WR_DATA8(0x00);
else if(USE_HORIZONTAL==1)LCD_WR_DATA8(0xC0);
else if(USE_HORIZONTAL==2)LCD_WR_DATA8(0x70);
else LCD_WR_DATA8(0xA0);

LCD_WR_REG(0x3A); 
LCD_WR_DATA8(0x05);

LCD_WR_REG(0xB2);
LCD_WR_DATA8(0x0C);
LCD_WR_DATA8(0x0C);
LCD_WR_DATA8(0x00);
LCD_WR_DATA8(0x33);
LCD_WR_DATA8(0x33);

LCD_WR_REG(0xB7); 
LCD_WR_DATA8(0x35);

LCD_WR_REG(0xBB);
LCD_WR_DATA8(0x37);

LCD_WR_REG(0xC0);
LCD_WR_DATA8(0x2C);

LCD_WR_REG(0xC2);
LCD_WR_DATA8(0x01);

LCD_WR_REG(0xC3);
LCD_WR_DATA8(0x12);

LCD_WR_REG(0xC4);
LCD_WR_DATA8(0x20);

LCD_WR_REG(0xC6); 
LCD_WR_DATA8(0x0F);

LCD_WR_REG(0xD0); 
LCD_WR_DATA8(0xA4);
LCD_WR_DATA8(0xA1);

LCD_WR_REG(0xE0);
LCD_WR_DATA8(0xD0);
LCD_WR_DATA8(0x04);
LCD_WR_DATA8(0x0D);
LCD_WR_DATA8(0x11);
LCD_WR_DATA8(0x13);
LCD_WR_DATA8(0x2B);
LCD_WR_DATA8(0x3F);
LCD_WR_DATA8(0x54);
LCD_WR_DATA8(0x4C);
LCD_WR_DATA8(0x18);
LCD_WR_DATA8(0x0D);
LCD_WR_DATA8(0x0B);
LCD_WR_DATA8(0x1F);
LCD_WR_DATA8(0x23);

LCD_WR_REG(0xE1);
LCD_WR_DATA8(0xD0);
LCD_WR_DATA8(0x04);
LCD_WR_DATA8(0x0C);
LCD_WR_DATA8(0x11);
LCD_WR_DATA8(0x13);
LCD_WR_DATA8(0x2C);
LCD_WR_DATA8(0x3F);
LCD_WR_DATA8(0x44);
LCD_WR_DATA8(0x51);
LCD_WR_DATA8(0x2F);
LCD_WR_DATA8(0x1F);
LCD_WR_DATA8(0x1F);
LCD_WR_DATA8(0x20);
LCD_WR_DATA8(0x23);

LCD_WR_REG(0x21);

LCD_WR_REG(0x11); 
//Delay (120);

LCD_WR_REG(0x29); 
```

### CubeMX 生成初始化代码

驱动一个 SPI 屏幕，当然要确定 MCU 与屏幕的接线定义，查看F411 板的原理图

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可以看到线序如下表

| LCD 信号脚 | MCU 信号脚 |
| ------- | ------- |
| SCLK  | PA5 |
| MOSI  | PA7 |
| DC  | PC7 |
| CS  | PB6 |
| BL  | PA6 |
| RES | PA9 |

然后按照线序用 CubeMX 配置好管脚，并且设置 SPI 为八位，频率为F411的最高速度50MHz

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然后配置 DMA，设置为半字，也就是两字节，至于为什么后面再介绍

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### 添加 LCD 驱动

ST7789 的数据包分为两种，通过 DC 管脚来控制是 data 还是 command。

先写三个函数如下，发送命令和八位&十六位数据

```c
void LCD_WriteByte(uint8_t dat) {
  HAL_GPIO_WritePin(LCD_CS_GPIO_Port, LCD_CS_Pin, 0);
  HAL_GPIO_WritePin(LCD_DC_GPIO_Port, LCD_DC_Pin, 1);
  HAL_SPI_Transmit(&hspi1, &dat, 1, 0xffff);
  HAL_GPIO_WritePin(LCD_CS_GPIO_Port, LCD_CS_Pin, 1);
}

void LCD_WriteCmd(uint8_t cmd) {
  HAL_GPIO_WritePin(LCD_CS_GPIO_Port, LCD_CS_Pin, 0);
  HAL_GPIO_WritePin(LCD_DC_GPIO_Port, LCD_DC_Pin, 0);
  HAL_SPI_Transmit(&hspi1, &cmd, 1, 0xffff);
  HAL_GPIO_WritePin(LCD_CS_GPIO_Port, LCD_CS_Pin, 1);
}

void LCD_WriteWord(uint16_t dat) {
  LCD_WriteByte(dat >> 8);
  LCD_WriteByte(dat);
}
```

LCD 驱动万变不离其宗，我这里是分为四步：
1. 复位屏幕
2. 发送初始化序列（不使用 DMA），设置刷新域为全屏，SPI 修改为 16 位模式
3. 设置全屏缓存全局变量，显示内容写入变量
4. DMA 刷新全屏内容

复位屏幕的话就不多说了，直接 io 翻转即可，初始化序列厂家也有提供，直接发送即可，代码如下

```c
static void LCD_Reset(void)
{
  HAL_GPIO_WritePin(LCD_RES_GPIO_Port, LCD_RES_Pin, 0);
  HAL_Delay(200);
  HAL_GPIO_WritePin(LCD_RES_GPIO_Port, LCD_RES_Pin, 1);
  HAL_Delay(200);
}

void LCD_Init(void)
{
  LCD_Reset();

//************* Start Initial Sequence **********//
  LCD_WriteCmd(0x36);
  if (BOARD_LCD_ROTATION == 0)LCD_WriteByte(0x00);
  else if (BOARD_LCD_ROTATION == 1)LCD_WriteByte(0xC0);
  else if (BOARD_LCD_ROTATION == 2)LCD_WriteByte(0x70);
  else LCD_WriteByte(0xA0);

LCD_WriteCmd(0x3A);
  LCD_WriteByte(0x05);

LCD_WriteCmd(0xB2);
  LCD_WriteByte(0x0C);
  LCD_WriteByte(0x0C);
  LCD_WriteByte(0x00);
  LCD_WriteByte(0x33);
  LCD_WriteByte(0x33);

LCD_WriteCmd(0xB7);
  LCD_WriteByte(0x35);

LCD_WriteCmd(0xBB);
  LCD_WriteByte(0x37);

LCD_WriteCmd(0xC0);
  LCD_WriteByte(0x2C);

LCD_WriteCmd(0xC2);
  LCD_WriteByte(0x01);

LCD_WriteCmd(0xC3);
  LCD_WriteByte(0x12);

LCD_WriteCmd(0xC4);
  LCD_WriteByte(0x20);

LCD_WriteCmd(0xC6);
  LCD_WriteByte(0x0F);

LCD_WriteCmd(0xD0);
  LCD_WriteByte(0xA4);
  LCD_WriteByte(0xA1);

LCD_WriteCmd(0xE0);
  LCD_WriteByte(0xD0);
  LCD_WriteByte(0x04);
  LCD_WriteByte(0x0D);
  LCD_WriteByte(0x11);
  LCD_WriteByte(0x13);
  LCD_WriteByte(0x2B);
  LCD_WriteByte(0x3F);
  LCD_WriteByte(0x54);
  LCD_WriteByte(0x4C);
  LCD_WriteByte(0x18);
  LCD_WriteByte(0x0D);
  LCD_WriteByte(0x0B);
  LCD_WriteByte(0x1F);
  LCD_WriteByte(0x23);

LCD_WriteCmd(0xE1);
  LCD_WriteByte(0xD0);
  LCD_WriteByte(0x04);
  LCD_WriteByte(0x0C);
  LCD_WriteByte(0x11);
  LCD_WriteByte(0x13);
  LCD_WriteByte(0x2C);
  LCD_WriteByte(0x3F);
  LCD_WriteByte(0x44);
  LCD_WriteByte(0x51);
  LCD_WriteByte(0x2F);
  LCD_WriteByte(0x1F);
  LCD_WriteByte(0x1F);
  LCD_WriteByte(0x20);
  LCD_WriteByte(0x23);

LCD_WriteCmd(0x21);

LCD_WriteCmd(0x11);

LCD_WriteCmd(0x29);
  LCD_EnterBrushMode();
}
```

其中，LCD_EnterBrushMode 就是框选整个屏幕，然后后面向屏幕发送数据时都使用 DMA 来发送，且 SPI 更改为 16 位，代码如下

```c
static void LCD_SetFrame(uint16_t x0, uint16_t y0, uint16_t x1, uint16_t y1)
{
#if (BOARD_LCD_ROTATION == 0)
  LCD_WriteCmd(0x2a);
  LCD_WriteWord(x0);
  LCD_WriteWord(x1);
  LCD_WriteCmd(0x2b);
  LCD_WriteWord(y0);
  LCD_WriteWord(y1);
  LCD_WriteCmd(0x2c);
#elif (BOARD_LCD_ROTATION == 1)
  LCD_WriteCmd(0x2a);
  LCD_WriteWord(x0 + 2);
  LCD_WriteWord(x1 + 2);
  LCD_WriteCmd(0x2b);
  LCD_WriteWord(y0 + 1);
  LCD_WriteWord(y1 + 1);
  LCD_WriteCmd(0x2c);
#elif (BOARD_LCD_ROTATION == 2)
  LCD_WriteCmd(0x2a);
  LCD_WriteWord(x0 + 1);
  LCD_WriteWord(x1 + 1);
  LCD_WriteCmd(0x2b);
  LCD_WriteWord(y0 + 2);
  LCD_WriteWord(y1 + 2);
  LCD_WriteCmd(0x2c);
#elif (BOARD_LCD_ROTATION == 3)
  LCD_WriteCmd(0x2a);
  LCD_WriteWord(x0 + 1);
  LCD_WriteWord(x1 + 1);
  LCD_WriteCmd(0x2b);
  LCD_WriteWord(y0 + 2);
  LCD_WriteWord(y1 + 2);
  LCD_WriteCmd(0x2c);
#else
#error "The BOARD_LCD_ROTATION set error!!"
#endif
}

void LCD_EnterBrushMode(void)
{
/* Select full LCD screen */
  LCD_SetFrame(0, 0, BOARD_LCD_WIDTH - 1, BOARD_LCD_HEIGHT - 1);
  /* Set DC and CS state to DMA continuously transmits data to LCD */
  HAL_GPIO_WritePin(LCD_CS_GPIO_Port, LCD_CS_Pin, 0);
  HAL_GPIO_WritePin(LCD_DC_GPIO_Port, LCD_DC_Pin, 1);
  hspi1.Init.DataSize = SPI_DATASIZE_16BIT;
  HAL_SPI_Init(&hspi1);
}
```

为什么改为 16 位呢？是因为这个屏幕是 240\*240 分辨率的，所以像素点有 115200 字节，DMA 发送的函数的参数 Size 是 uint16_t 类型的，最大 65535，虽然可以修改 HAL 库代码，但是为了尽量不动库代码的原则，采取修改 SPI 和 DMA 为 16 位模式来解决，也就是 57600 个两字节，这样就可以正常使用这个库函数了。

再写一个 DMA 刷屏的函数
```c
volatile uint16_t lcd_tx_buf[BOARD_LCD_HEIGHT][BOARD_LCD_WIDTH]; /* LCD tx buffer. */
void LCD_ReflashFrame(void)
{
/* Enable DMA transmission */
  HAL_SPI_Transmit_DMA(&hspi1, (uint8_t *) lcd_tx_buf, BOARD_LCD_HEIGHT * BOARD_LCD_WIDTH);

}

void LCD_ClearWindow(uint16_t x0, uint16_t y0, uint16_t x1, uint16_t y1,
  uint16_t color)
{
  for (uint16_t j = y0; j < y1; j++)
  {
  for (uint16_t i = x0; i < x1; i++)
  {
    lcd_tx_buf[j]<i> = color;
  }
  }
  LCD_ReflashFrame();
}

```

### 点亮屏幕

在 main 函数中添加如下代码，延时是因为没有引出屏幕的 TE 管脚，所以为了避免 DMA 没有发送完的时候缓存区的内容就被修改而导致显示异常的问题就加了延时

```c
LCD_Init();
LCD_ClearWindow(0, 0, 240, 240, LCD_COLOR_RED);
HAL_Delay(50);
LCD_ClearWindow(0, 0, 160, 160, LCD_COLOR_GREEN);
HAL_Delay(50);
LCD_ClearWindow(0, 0, 80, 80, LCD_COLOR_BLUE);
```

最终效果如下

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serialworld

谢谢分享！直接画好扩展板了。

deng0713

请问这个扩展版是嘉立创元件库里的吗还是大佬自己画的(☆▽☆)

pomin

deng0713 发表于 2024-4-14 22:26 请问这个扩展版是嘉立创元件库里的吗还是大佬自己画的(☆▽☆)

自己画的

emma2015

F411 板没收到时就画了一个接口拓展板子，外接屏幕、按键、RS485 接口

【STM32F411Nucleo测评】驱动 1.3 寸 LCD 屏幕 [复制链接]

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