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/relay_control.c

@@ -0,0 +1,102 @@
+/**
+  ******************************************************************************
+  * @file    relay_control.c
+  * @brief   继电器控制模块实现
+  * @author  Application Layer
+  * @version 1.1
+  ******************************************************************************
+  * @attention
+  * 本模块实现继电器的安全控制
+  * 关键特性：
+  * 1. 最小切换间隔保护，防止频繁切换损坏继电器
+  * 2. 状态记录，支持诊断
+  * 3. 调试日志输出
+  * 
+  * 修订历史：
+  * v1.1 - 修复审查报告中危-9/10：对齐RELAY_COUNT与参数校验逻辑
+  ******************************************************************************
+  */
+
+#include "relay_control.h"
+#include "uart2_print.h"
+#include "main.h"
+
+#define DEBUG_RELAY  1
+
+#if DEBUG_RELAY
+#define DEBUG_LOG(fmt, ...)  UART2_Print_Printf("[RELAY] " fmt "\r\n", ##__VA_ARGS__)
+#else
+#define DEBUG_LOG(fmt, ...)
+#endif
+
+#define MAX_RELAY_ID    4
+
+static bool current_states[MAX_RELAY_ID] = {false, false, false, false};
+static uint32_t last_toggle_tick = 0;
+static uint32_t toggle_count = 0;
+
+void Relay_Init(void)
+{
+    HAL_GPIO_WritePin(RL_Control_GPIO_Port, RL_Control_Pin, GPIO_PIN_RESET);
+    
+    for (int i = 0; i < MAX_RELAY_ID; i++) {
+        current_states[i] = false;
+    }
+    last_toggle_tick = 0;
+    toggle_count = 0;
+    
+    DEBUG_LOG("Init OK, state=OFF");
+}
+
+void Relay_SetState(uint8_t relay_id, bool state)
+{
+    if (relay_id < 1 || relay_id > MAX_RELAY_ID) {
+        DEBUG_LOG("Invalid relay ID: %d", relay_id);
+        return;
+    }
+    
+    uint32_t current_tick = HAL_GetTick();
+    if (current_tick - last_toggle_tick < RELAY_MIN_INTERVAL) {
+        DEBUG_LOG("Toggle too fast, ignored");
+        return;
+    }
+    
+    uint8_t idx = relay_id - 1;
+    
+    if (current_states[idx] == state) {
+        DEBUG_LOG("State unchanged: %s", state ? "ON" : "OFF");
+        return;
+    }
+    
+    if (relay_id == 1) {
+        HAL_GPIO_WritePin(RL_Control_GPIO_Port, RL_Control_Pin, 
+                           state ? GPIO_PIN_SET : GPIO_PIN_RESET);
+    }
+    
+    current_states[idx] = state;
+    last_toggle_tick = current_tick;
+    toggle_count++;
+    
+    DEBUG_LOG("Relay %d -> %s (count=%lu)", relay_id, state ? "ON" : "OFF", toggle_count);
+}
+
+bool Relay_GetState(uint8_t relay_id)
+{
+    if (relay_id < 1 || relay_id > MAX_RELAY_ID) {
+        return false;
+    }
+    return current_states[relay_id - 1];
+}
+
+void Relay_Toggle(uint8_t relay_id)
+{
+    if (relay_id < 1 || relay_id > MAX_RELAY_ID) {
+        return;
+    }
+    Relay_SetState(relay_id, !current_states[relay_id - 1]);
+}
+
+uint32_t Relay_GetToggleCount(void)
+{
+    return toggle_count;
+}