11.6：完善多任务和消息队列机制。

STM32/Environment_Node/System/USART3.h

@@ -0,0 +1,31 @@
+#ifndef __USART3_H__
+#define __USART3_H__
+
+#include "stm32f10x.h"                  // Device header
+#include "FreeRTOS.h"
+#include "queue.h"
+// #include "semphr.h"
+#include <stdio.h>
+#include <stdarg.h>
+#include <string.h>
+
+#define USART3_GPIO_PIN_TX                                      GPIO_Pin_10
+#define USART3_GPIO_PIN_RX                                      GPIO_Pin_11
+#define USART3_GPIO_PIN_ATK_AUX                                 GPIO_Pin_4 // PA4
+#define USART3_GPIO_PIN_ATK_MD0                                 GPIO_Pin_3 // PB3
+#define USART3_QUEUE_LENGTH                                     256
+
+typedef struct 
+{
+    /* data */
+    uint8_t *ucRxBuffer;
+    uint8_t ucIndex;
+}Usart3RecBuffer_t;
+
+void vUsart3Init(uint32_t ulUsart3Baudrate);
+void vUsart3SendByte(uint8_t ucByte);
+void vUsart3SendArray(uint8_t *pucArray, uint16_t usLength);
+void vUsart3SendString(char *pcString);
+void vUsart3Printf(char *format, ...);
+
+#endif