3.27_433：添加UART2调试打印、IO监控、指令解析和继电器控制模块。

能够接收UART2指令控制继电器开关，或向UART2发送四路IO输入状态，并使用轮询方式检测IO状态进行及时反馈。

Core/Src/uart2_print.c

@@ -0,0 +1,224 @@
+/**
+  ******************************************************************************
+  * @file    uart2_print.c
+  * @brief   UART2调试打印模块实现
+  * @author  Application Layer
+  * @version 1.1
+  ******************************************************************************
+  * @attention
+  * 本模块实现基于环形缓冲区的非阻塞调试信息输出
+  * 关键特性：
+  * 1. 环形缓冲区避免数据丢失
+  * 2. 中断安全，支持ISR中调用
+  * 3. 非阻塞发送，不影响实时性
+  * 
+  * 修订历史：
+  * v1.1 - 修复审查报告高危-1/2/3，中危-4
+  ******************************************************************************
+  */
+
+#include "uart2_print.h"
+#include "usart.h"
+#include <string.h>
+#include <stdio.h>
+
+#define DEBUG_PRINT_ENABLED  1
+
+#if DEBUG_PRINT_ENABLED
+#define DEBUG_LOG(fmt, ...)  UART2_Print_Printf("[UART2] " fmt "\r\n", ##__VA_ARGS__)
+#else
+#define DEBUG_LOG(fmt, ...)
+#endif
+
+typedef struct {
+    uint8_t  buffer[UART2_TX_BUFFER_SIZE];
+    volatile uint16_t head;
+    volatile uint16_t tail;
+    volatile uint16_t count;
+    volatile bool     is_sending;
+    volatile uint16_t overflow_count;
+} ring_buffer_t;
+
+static ring_buffer_t tx_ring = {0};
+
+void UART2_Print_Init(void)
+{
+    tx_ring.head = 0;
+    tx_ring.tail = 0;
+    tx_ring.count = 0;
+    tx_ring.is_sending = false;
+    tx_ring.overflow_count = 0;
+    
+    DEBUG_LOG("Init OK, buffer size: %d", UART2_TX_BUFFER_SIZE);
+}
+
+void UART2_Print_Send(const uint8_t *data, uint16_t len)
+{
+    if (len == 0 || data == NULL) {
+        return;
+    }
+    
+    uint16_t written = 0;
+    bool needs_kickoff = false;
+    
+    __disable_irq();
+    for (uint16_t i = 0; i < len; i++) {
+        if (tx_ring.count >= UART2_TX_BUFFER_SIZE) {
+            tx_ring.overflow_count++;
+            break;
+        }
+        
+        tx_ring.buffer[tx_ring.head] = data[i];
+        tx_ring.head = (tx_ring.head + 1) % UART2_TX_BUFFER_SIZE;
+        tx_ring.count++;
+        written++;
+    }
+    
+    if (written > 0 && !tx_ring.is_sending) {
+        tx_ring.is_sending = true;
+        needs_kickoff = true;
+    }
+    __enable_irq();
+    
+    if (needs_kickoff) {
+        uint8_t byte;
+        __disable_irq();
+        byte = tx_ring.buffer[tx_ring.tail];
+        __enable_irq();
+        HAL_UART_Transmit_IT(&huart2, &byte, 1);
+    }
+}
+
+void UART2_Print_String(const char *str)
+{
+    if (str == NULL) {
+        return;
+    }
+    UART2_Print_Send((const uint8_t *)str, strlen(str));
+}
+
+void UART2_Print_Printf(const char *fmt, ...)
+{
+    if (fmt == NULL) {
+        return;
+    }
+    
+    char buffer[128];
+    va_list args;
+    
+    va_start(args, fmt);
+    int len = vsnprintf(buffer, sizeof(buffer), fmt, args);
+    va_end(args);
+    
+    if (len >= 0) {
+        if (len >= (int)sizeof(buffer)) {
+            len = sizeof(buffer) - 1;
+        }
+        UART2_Print_Send((const uint8_t *)buffer, len);
+    }
+}
+
+void UART2_Print_Task(void)
+{
+    uint8_t byte;
+    uint16_t current_tail;
+    
+    __disable_irq();
+    if (tx_ring.is_sending || tx_ring.count == 0) {
+        __enable_irq();
+        return;
+    }
+    
+    current_tail = tx_ring.tail;
+    tx_ring.tail = (tx_ring.tail + 1) % UART2_TX_BUFFER_SIZE;
+    tx_ring.count--;
+    tx_ring.is_sending = true;
+    byte = tx_ring.buffer[current_tail];
+    __enable_irq();
+    
+    HAL_UART_Transmit_IT(&huart2, &byte, 1);
+}
+
+void UART2_Print_TxCpltCallback(void)
+{
+    uint8_t byte;
+    uint16_t current_tail;
+    bool has_more = false;
+    
+    __disable_irq();
+    tx_ring.is_sending = false;
+    
+    if (tx_ring.count > 0) {
+        current_tail = tx_ring.tail;
+        tx_ring.tail = (tx_ring.tail + 1) % UART2_TX_BUFFER_SIZE;
+        tx_ring.count--;
+        tx_ring.is_sending = true;
+        byte = tx_ring.buffer[current_tail];
+        has_more = true;
+    }
+    __enable_irq();
+    
+    if (has_more) {
+        HAL_UART_Transmit_IT(&huart2, &byte, 1);
+    }
+}
+
+bool UART2_Print_IsBusy(void)
+{
+    bool busy;
+    __disable_irq();
+    busy = tx_ring.is_sending || (tx_ring.count > 0);
+    __enable_irq();
+    return busy;
+}
+
+uint16_t UART2_Print_Available(void)
+{
+    uint16_t available;
+    __disable_irq();
+    available = UART2_TX_BUFFER_SIZE - tx_ring.count;
+    __enable_irq();
+    return available;
+}
+
+uint16_t UART2_Print_GetOverflowCount(void)
+{
+    return tx_ring.overflow_count;
+}
+
+/**
+  * @brief  printf重定向函数 (Keil MDK)
+  * @note   重定向标准库printf到UART2
+  * @param  ch: 待发送字符
+  * @param  f: 文件指针(未使用)
+  * @retval 发送的字符
+  */
+#if defined(__CC_ARM) || defined(__ARMCC_VERSION)
+int fputc(int ch, FILE *f)
+{
+    (void)f;
+    UART2_Print_Send((uint8_t *)&ch, 1);
+    return ch;
+}
+#endif
+
+/**
+  * @brief  printf重定向函数 (GCC)
+  * @note   重定向标准库printf到UART2
+  * @param  ch: 待发送字符
+  * @retval 发送的字符
+  */
+#if defined(__GNUC__)
+int __io_putchar(int ch)
+{
+    UART2_Print_Send((uint8_t *)&ch, 1);
+    return ch;
+}
+
+int _write(int file, char *ptr, int len)
+{
+    (void)file;
+    UART2_Print_Send((uint8_t *)ptr, len);
+    return len;
+}
+#endif