1.查詢uart配置過程
文件路徑: /drivers/board.h

使能RTT uart驅動

2.使能usart3總線
打開 /drivers/board.h
#define BSP_UART3_RX_USING_DMA
#define BSP_USING_UART3
#define BSP_UART1_TX_PIN "PB10"
#define BSP_UART1_RX_PIN "PB11"
3.使能HAL庫相應模塊
打開 /drivers/ stm32f7xx_hal_conf.h
使能 #define HAL_UART_MODULE_ENABLED
4.添加硬件初始化代碼
通過 stm32cubemx工具使能uart2硬件,在一下路徑
\Core\Src\stm32f7xx_hal_msp.c中將HAL_UART_MspInit拷貝到 /drivers/board.c中
void HAL_UART_MspInit(UART_HandleTypeDef* uartHandle) { GPIO_InitTypeDef GPIO_InitStruct = {0}; if(uartHandle->Instance==USART3) { /* USART3 clock enable */ __HAL_RCC_USART3_CLK_ENABLE(); __HAL_RCC_GPIOB_CLK_ENABLE(); /**USART3 GPIO Configuration PB10 ------> USART3_TX PB11 ------> USART3_RX */ GPIO_InitStruct.Pin = GPIO_PIN_10; GPIO_InitStruct.Mode = GPIO_MODE_AF_PP; GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_HIGH; HAL_GPIO_Init(GPIOB, &GPIO_InitStruct); GPIO_InitStruct.Pin = GPIO_PIN_11; GPIO_InitStruct.Mode = GPIO_MODE_INPUT; GPIO_InitStruct.Pull = GPIO_NOPULL; HAL_GPIO_Init(GPIOB, &GPIO_InitStruct); } }
5.驗證

6.測試代碼
#include <rtthread.h> #define SAMPLE_UART_NAME "uart3" /* 用於接收消息的信號量 */ static struct rt_semaphore rx_sem; static rt_device_t serial; /* 接收數據回調函數 */ static rt_err_t uart_input(rt_device_t dev, rt_size_t size) { /* 串口接收到數據后產生中斷,調用此回調函數,然后發送接收信號量 */ rt_sem_release(&rx_sem); return RT_EOK; } /** * 串口接受線程 * @param parameter */ static void serial_thread_entry(void *parameter) { char ch; while (1) { /* 從串口讀取一個字節的數據,沒有讀取到則等待接收信號量 */ while (rt_device_read(serial, -1, &ch, 1) != 1) { /* 阻塞等待接收信號量,等到信號量后再次讀取數據 */ rt_sem_take(&rx_sem, RT_WAITING_FOREVER); } /* 讀取到的數據通過串口錯位輸出 */ ch = ch + 1; rt_device_write(serial, 0, &ch, 1); } } static int uart_sample(int argc, char *argv[]) { rt_err_t ret = RT_EOK; char uart_name[RT_NAME_MAX]; char str[] = "hello RT-Thread!\r\n"; if (argc == 2) { rt_strncpy(uart_name, argv[1], RT_NAME_MAX); } else { rt_strncpy(uart_name, SAMPLE_UART_NAME, RT_NAME_MAX); } /* 查找系統中的串口設備 */ serial = rt_device_find(uart_name); if (!serial) { rt_kprintf("find %s failed!\n", uart_name); return RT_ERROR; } /* 初始化信號量 */ rt_sem_init(&rx_sem, "rx_sem", 0, RT_IPC_FLAG_FIFO); /* 以中斷接收及輪詢發送模式打開串口設備 */ rt_device_open(serial, RT_DEVICE_FLAG_INT_RX); /* 設置接收回調函數 */ rt_device_set_rx_indicate(serial, uart_input); /* 發送字符串 */ rt_device_write(serial, 0, str, (sizeof(str) - 1)); /* 創建 serial 線程 */ rt_thread_t thread = rt_thread_create("serial", serial_thread_entry, RT_NULL, 1024, 25, 10); /* 創建成功則啟動線程 */ if (thread != RT_NULL) { rt_thread_startup(thread); } else { ret = RT_ERROR; } return ret; } /* 導出到 msh 命令列表中 */ MSH_CMD_EXPORT(uart_sample, uart device sample);

