STM32F103 "Hello World" Part3

Purpose
本篇實際操作STM32CubeMX去生成initialization code
Development board在Part1介紹

預計demo功能為USART, GPIO, HSE
USART dump "Hello World",
GPIO toggle LED,
使用Oscillator -> PLL -> 72MHz, 為system clock

STM32CubeMX Version 4.25

Pin assignment
USART1 : RX(PA_10), TX(PA_9)
LED : PC_13
External Oscillator : OSC_IN(PD_0) & OSC_OUT(PD_1)
2-Wire Serial Debug : SWDIO(PA_13) & SWCLK(PA_14)

Step by step
Step 1. click New Project

Step 2. 選擇MCU型號, 可透過下方Filter Search挑選MCU, 或直接Part Number Search輸入型號, 找到後連點兩次進去主畫面

Step 3. 主畫面
在Pinout分頁中可設定開啟或關閉各項Peripherals, 右邊為Chip View, 檢查Pin使用情況

Step 4. 設定各Peripherals, 如下圖左

• RCC config

選擇High Speed Clock (HSE) 為Crystal/Ceramic Resonator

• SYS config

選擇Debug為 Serial Wire

• USART1 config

選擇Mode為Asynchronous

• GPIO config

於Chip View選擇PC13為GPIO Output

設定好後, 右邊Chip View顯示相對應的Pin assignment
被設定過的Peripherals與Pin會以不同顏色表示
於官方TRM (UM1718)有詳細定義, 下方列出常見define

Step 5. 切換至Clock Configuration可看到Clock Tree
使用外部8MHz Oscillator, 經倍頻到72MHz (SYS_CLK max.), 配置如下圖
以HSE為PLL Source -> PLLMul*9 -> System Clock Mux選擇PLLCLK

如設定出現錯誤, 框底以紅色警示

說明

Step 6. 切換至Configuration頁面, 可詳細設定Periphals

USART1
Baud rate = 115200bps

GPIO
使用自定義名稱(User Label), 於Pinout將顯示自定義接腳名稱

Step 7. Project Setting
Menu -> Project -> Setting
相關設定供參考, 依喜好設定
官方TRM 5.8章Project Settings window

• Project頁面

設定專案名稱, 路徑與Toolchain

• Code Generator頁面

選擇Copy only the necessary library files

只複製有需要的Library, 第一項會將Middleware Level的Library也一併放進Project, 容量過大

Step 8. Generate Code
Menu -> Project -> Generate Code

生成完Initialization code, 跳出一對話框, 如下圖

STM32CubeMX操作流程如上述, 接下來轉至Keil進行coding!


Step 9. Open Project
以Keil開啟後, project tree如下
main.c 位於./Application/User, 主要執行system clock configuration, HAL peripherals initialization, user code
stm32f1xx_it.c 為interrupt handler

在STM32CubeMX產生的專案裡, 可看到許多USER CODE BEGIN & END的註解, 請將code撰寫於BEGIN & END的範圍內, 避免re-generate code時造成竭盡心力撰寫的code遺失

  /* USER CODE BEGIN WHILE */
  while (1)
  {

  /* USER CODE END WHILE */

Step 10. Development code

設計功能為間隔1sec 透過UART 發送"Hello World\r\n", 同時PC13 LED toggle

UART 發送可分為polling, interrupt, DMA, 這裡以polling 為範例
由於選擇的是USART1 - asynchronous mode, 以STM32F103C8T6 為例, PA9 PA10 為USART1 interface, 分別是UART_TX, UART_RX

上述設計功能以下列3個API完成

HAL_UART_Driver operation functions

HAL_GPIO_Driver operation functions

HAL_System_Driver operation functions

• Transmit the string by using HAL_UART_Transmit

int main(void)
{
    /* USER CODE BEGIN 1 */
    char str[] = "Hello World\r\n";
    /* USER CODE END 1 */

    /* MCU Configuration----------------------------------------------------------*/

    /* Reset of all peripherals, Initializes the Flash interface and the Systick. */
    HAL_Init();

    /* USER CODE BEGIN Init */

    /* USER CODE END Init */

    /* Configure the system clock */
    SystemClock_Config();

    /* USER CODE BEGIN SysInit */

    /* USER CODE END SysInit */

    /* Initialize all configured peripherals */
    MX_GPIO_Init();
    MX_USART1_UART_Init();
    /* USER CODE BEGIN 2 */

    /* USER CODE END 2 */

    /* Infinite loop */
    /* USER CODE BEGIN WHILE */
    while (1)
    {
        if (HAL_UART_Transmit(&huart1, (uint8_t *)str, sizeof(str), 0xFFFF) != HAL_OK) {
            Error_Handler();
        }
        HAL_GPIO_Toggle(LED_BUILTIN_GPIO_Port, LED_BUILTIN_Pin);
        HAL_Delay(1000);
        /* USER CODE END WHILE */

        /* USER CODE BEGIN 3 */

    }
    /* USER CODE END 3 */

}

• 以sprintf function增加靈活性, 可快速字串格式設定

int main(void)
{
    /* USER CODE BEGIN 1 */
    char str[100];
    uint32_t i;
    /* USER CODE END 1 */

    /* MCU Configuration----------------------------------------------------------*/

    /* Reset of all peripherals, Initializes the Flash interface and the Systick. */
    HAL_Init();

    /* USER CODE BEGIN Init */

    /* USER CODE END Init */

    /* Configure the system clock */
    SystemClock_Config();

    /* USER CODE BEGIN SysInit */

    /* USER CODE END SysInit */

    /* Initialize all configured peripherals */
    MX_GPIO_Init();
    MX_USART1_UART_Init();
    /* USER CODE BEGIN 2 */

    /* USER CODE END 2 */

    /* Infinite loop */
    /* USER CODE BEGIN WHILE */
    i = 0;
    while (1)
    {
        sprintf(str, "Hello World, CNT: %d\r\n", i++);
        if (HAL_UART_Transmit(&huart1, (uint8_t *)str, sizeof(str), 0xFFFF) != HAL_OK) {
            Error_Handler();
        }
        /* USER CODE END WHILE */

        /* USER CODE BEGIN 3 */
        HAL_GPIO_TogglePin(LED_BUILTIN_GPIO_Port, LED_BUILTIN_Pin);
        HAL_Delay(1000);
    }
    /* USER CODE END 3 */

}

• Implement Print function

參考C:\Users\[User Name]\STM32Cube\Repository\STM32Cube_FW_F1_V1.6.1\Projects\STM32F103RB-Nucleo\Examples\UART\UART_Printf 範例

於USER CODE BEGIN PV & USER CODE END PV貼以下code

/* USER CODE BEGIN PV */
/* Private variables ---------------------------------------------------------*/

#ifdef __GNUC__
/* With GCC, small printf (option LD Linker->Libraries->Small printf
set to 'Yes') calls __io_putchar() */
#define PUTCHAR_PROTOTYPE int __io_putchar(int ch)
#else
#define PUTCHAR_PROTOTYPE int fputc(int ch, FILE *f)
#endif /* __GNUC__ */
PUTCHAR_PROTOTYPE
{
    /* Place your implementation of fputc here */
    /* e.g. write a character to the USART1 and Loop until the end of transmission */
    HAL_UART_Transmit(&huart1, (uint8_t *)&ch, 1, 0xFFFF);

return ch;
}

/* USER CODE END PV */

於while loop 中直接call printf 即可

    /* Infinite loop */
    /* USER CODE BEGIN WHILE */
    i = 0;
    while (1)
    {
        printf("Hello World, CNT: %d\r\n", i++);
        /* USER CODE END WHILE */

        /* USER CODE BEGIN 3 */
        HAL_GPIO_TogglePin(LED_BUILTIN_GPIO_Port, LED_BUILTIN_Pin);
        HAL_Delay(1000);
    }
    /* USER CODE END 3 */

Resources
UM1718
http://www.st.com/resource/en/user_manual/dm00104712.pdf

STM32CubeMX介绍、下载与安装
https://blog.csdn.net/ybhuangfugui/article/details/52225736

STM32CubeMX新建工程+基本IO配置过程
https://blog.csdn.net/ybhuangfugui/article/details/52281260

STM32CubeMX系列教程
http://www.waveshare.net/study/portal.php?mod=list&catid=38