STM32F4-Base/Drivers/BSP/RS485/rs485.c

/*
 * 模å<C2A1>—å<E28094><C3A5>称：RS-485 å<>Šå<C5A0>Œå·¥é€šä¿¡é©±åŠ¨
 * 模å<C2A1>—功能：RS-485 å<>Šå<C5A0>Œå·¥é€šä¿¡é©±åŠ¨å®žçŽ°ï¼Œæ ¸å¿ƒè¦<C3A8>点：
 *          1. å<>‘é€<C3A9>å‰<C3A5>拉高 DE（切æ<E280A1>¢åˆ°å<C2B0>‘é€<C3A9>æ€<C3A6>）
 *          2. HAL_UART_Transmit 内部已等ï¿?TC（å<CB86>‘é€<C3A9>完æˆ<C3A6>）标志
 *          3. å<>‘é€<C3A9>完毕å<E280A2>Žæ‹‰ä½Ž DE（切回接收æ€<C3A6>）
 *          4. 使用 HAL_UARTEx_ReceiveToIdle_IT 实现å<C2B0>˜é•¿å¸§æŽ¥ï¿? *          å<>‚考：ST AN3070 应用笔记ã€<C3A3>controllerstech.com RS485 教程
 * 适用平å<C2B3>°ï¼šSTM32F4 系列
 * 作者：王建� * 创建日期�026-07-18
 * 修改记录ï¿? *     2026-07-18  王建ï¿? 创建åˆ<C3A5>始版本
 */

#include "rs485.h"

/*
 * 内部辅助ï¿?- æ–¹å<C2B9>‘控制
 */
#define RS485_DIR_TX(h)  HAL_GPIO_WritePin((h)->dir_port, (h)->dir_pin, GPIO_PIN_SET)
#define RS485_DIR_RX(h)  HAL_GPIO_WritePin((h)->dir_port, (h)->dir_pin, GPIO_PIN_RESET)

/*
 * 公共函数实现
 */

/*
 * 函数功能：åˆ<C3A5>始化 RS-485 å<>¥æŸ„
 * å…¥å<C2A5>£å<C2A3>‚数：handle   - RS-485 å<>¥æŸ„指针
 *           huart    - UART 外设å<C2BE>¥æŸ„
 *           dir_port - DE 引脚 GPIO 端å<C2AF>£
 *           dir_pin  - DE 引脚 GPIO ç¼–å<E28093>·
 * 返回值：ï¿? * é™<C3A9>定æ<C5A1>¡ä»¶ï¼šUART ï¿?GPIO 须先ï¿?CubeMX 完æˆ<C3A6>åˆ<C3A5>始ï¿? * 函数说明：åˆ<C3A5>始化å<E28093>Žç«‹å<E280B9>³å°† DE 拉低，使 RS-485 收å<C2B6>‘器处于接收状ï¿? */
void rs485_init(rs485_handle_t *p_handle,
                UART_HandleTypeDef *p_huart,
                GPIO_TypeDef *p_dir_port,
                uint16_t dir_pin) {
    p_handle->huart    = p_huart;
    p_handle->dir_port = p_dir_port;
    p_handle->dir_pin  = dir_pin;
    p_handle->rx_size  = 0;

    /* 默认进入接收状�?*/
    RS485_DIR_RX(p_handle);
}

/*
 * 函数功能：阻塞方å¼<C3A5>å<EFBFBD>‘é€<C3A9>æ•°ï¿? * å…¥å<C2A5>£å<C2A3>‚数：handle  - RS-485 å<>¥æŸ„指针
 *           data    - å¾…å<E280A6>‘é€<C3A9>æ•°æ<C2B0>®ç¼“冲区
 *           len     - å¾…å<E280A6>‘é€<C3A9>字节数
 *           timeout - å<>‘é€<C3A9>超时（ms），ï¿?0 使用默认ï¿? * 返回值：HAL_OK / HAL_TIMEOUT / HAL_ERROR
 * é™<C3A9>定æ<C5A1>¡ä»¶ï¼šé¡»åœ¨ä¸»å¾ªçŽ¯ï¿?RTOS 任务中调用，ä¸<C3A4>å<EFBFBD>¯ï¿?UART 中断中调ï¿? * 函数说明ï¿? *   æ—¶åº<C3A5>：DE=HIGH ï¿?UART å<>‘�?N 字节 ï¿?ï¿?TC ï¿?DE=LOW
 *   HAL_UART_Transmit 内部会等ï¿?TXE（å<CB86>‘é€<C3A9>寄存器空）é€<C3A9>字节æ<E2809A>¬æ•°æ<C2B0>®ï¿? *   最å<E282AC>Žè¿˜ä¼šç­‰ï¿?TC（å<CB86>‘é€<C3A9>完æˆ<C3A6>）标志，确ä¿<C3A4>最å<E282AC>Žä¸€å­—节的å<E2809E>œæ­¢ä½<C3A4>已移出�? *   因此返回å<C5BE>Žå†<C3A5>拉低 DE 是安全的
 */
HAL_StatusTypeDef rs485_transmit(rs485_handle_t *p_handle,
                                  const uint8_t *p_data,
                                  uint16_t len,
                                  uint32_t timeout) {
    HAL_StatusTypeDef status = HAL_OK;

    if (timeout == 0U) {
        timeout = RS485_TIMEOUT_DEFAULT;
    }

    /* 1. 切æ<E280A1>¢åˆ°å<C2B0>‘é€<C3A9>状ï¿?*/
    RS485_DIR_TX(p_handle);

    /* 2. 阻塞å<C5BE>‘é€<C3A9>（内部等待 TCï¿?*/
    status = HAL_UART_Transmit(p_handle->huart,
                                (uint8_t *)p_data,
                                len,
                                timeout);

    /* 3. å<>‘é€<C3A9>完毕或超时，切回接收状ï¿?*/
    RS485_DIR_RX(p_handle);

    return status;
}

/*
 * 函数功能：å<C5A1>¯åŠ¨ä¸­æ–­æ–¹å¼<C3A5>接收（IDLE 空闲帧检测）
 * å…¥å<C2A5>£å<C2A3>‚数：handle    - RS-485 å<>¥æŸ„指针
 *           buf       - 接收缓冲� *           buf_size  - 缓冲区最大容� * 返回值：HAL_OK / HAL_ERROR
 * é™<C3A9>定æ<C5A1>¡ä»¶ï¼šUART 须已开å<E282AC>¯å…¨å±€ä¸­æ–­ï¼ˆNVIC 使能ï¿? * 函数说明ï¿? *   使用 HAL_UARTEx_ReceiveToIdle_IT 实现å<C2B0>˜é•¿å¸§æŽ¥æ”¶ï¿½? *   ï¿?UART 总线空闲超过 1 个字符时间å<C2B4>Žï¼Œç¡¬ä»¶è§¦ï¿?IDLE 中断ï¿? *   HAL 自动调用 HAL_UARTEx_RxEventCallback 并返回已接收字节数�? *   用户须在该回调中é‡<C3A9>新调用本函数é‡<C3A9>æ–°å¼€å<E282AC>¯æŽ¥ï¿? */
HAL_StatusTypeDef rs485_receive_start(rs485_handle_t *p_handle,
                                       uint8_t *p_buf,
                                       uint16_t buf_size) {
    p_handle->rx_size = 0;
    return HAL_UARTEx_ReceiveToIdle_IT(p_handle->huart, p_buf, buf_size);
}

/*
 * 函数功能：缓存最近一次接收的字节ï¿? * å…¥å<C2A5>£å<C2A3>‚数：handle - RS-485 å<>¥æŸ„指针
 *           size   - 本次接收到的字节ï¿? * 返回值：ï¿? * é™<C3A9>定æ<C5A1>¡ä»¶ï¼šé¡»ï¿?HAL_UARTEx_RxEventCallback 中调ï¿? */
void rs485_rx_set_size(rs485_handle_t *p_handle, uint16_t size) {
    p_handle->rx_size = size;
}

/*
 * 函数功能：获å<C2B7>–最近一次接收的字节ï¿? * å…¥å<C2A5>£å<C2A3>‚数：handle - RS-485 å<>¥æŸ„指针
 * 返回值：字节� */
uint16_t rs485_rx_get_size(const rs485_handle_t *p_handle) {
    return p_handle->rx_size;
}