| 再来配置一下debug接口。配置串口位于debug_uart文件中，我把原代码中的DMA相关代码删除，只剩串口初始化和fputc函数。具体的代码如下
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- void
- dbg_setup_uart_default()
- {
- USART_InitTypeDef USART_InitStructure;
- GPIO_InitTypeDef GPIO_InitStructure;
- //使能GPIOA时钟
- RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA\
- | RCC_APB2Periph_USART1 ,ENABLE);
- //PA9 TX1 复用推挽输出
- GPIO_InitStructure.GPIO_Pin= GPIO_Pin_9;
- GPIO_InitStructure.GPIO_Speed= GPIO_Speed_50MHz;
- GPIO_InitStructure.GPIO_Mode= GPIO_Mode_AF_PP;
- GPIO_Init(GPIOA,&GPIO_InitStructure);
- //PA10 RX1 浮动输入
- GPIO_InitStructure.GPIO_Pin= GPIO_Pin_10;
- GPIO_InitStructure.GPIO_Speed= GPIO_Speed_50MHz;
- GPIO_InitStructure.GPIO_Mode= GPIO_Mode_IN_FLOATING;
- GPIO_Init(GPIOA,&GPIO_InitStructure);
- USART_InitStructure.USART_BaudRate= 9600;
- USART_InitStructure.USART_WordLength= USART_WordLength_8b;
- USART_InitStructure.USART_StopBits= USART_StopBits_1;
- USART_InitStructure.USART_Parity= USART_Parity_No;
- USART_InitStructure.USART_HardwareFlowControl= USART_HardwareFlowControl_None;
- USART_InitStructure.USART_Mode= USART_Mode_Rx | USART_Mode_Tx;
- USART_Init(USART1,&USART_InitStructure);
- //使能USART1
- USART_Cmd(USART1,ENABLE);
- }
- int fputc(intch, FILE* f)
- {
- USART_SendData(USART1,(uint8_t)ch);
- while(USART_GetFlagStatus(USART1, USART_FLAG_TXE)== RESET );
- return ch;
- }
5.新建一个任务
通过上网搜索和阅读书籍，我写了以下任务。
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- PROCESS(blink_process, "Blink");
- AUTOSTART_PROCESSES(&blink_process);
- PROCESS_THREAD(blink_process, ev, data)
- {
- PROCESS_BEGIN();
- while(1)
- {
- static structetimer et;
- etimer_set(&et, CLOCK_SECOND);
- PROCESS_WAIT_EVENT_UNTIL(etimer_expired(&et));
- //打开LED
- GPIO_ResetBits(GPIOC,GPIO_Pin_6);
- printf("LEDON\r\n");
- etimer_set(&et, CLOCK_SECOND);
- PROCESS_WAIT_EVENT_UNTIL(etimer_expired(&et));
- //关闭LED
- GPIO_SetBits(GPIOC,GPIO_Pin_6);
- printf("LEDOFF\r\n");
- }
- PROCESS_END();
- }
该任务是从contiki-2.5中例子修改而来的。任务非常的简单，打开LED，通过串口发送提示信息，然后关闭LED，通过串口发送提示信息。 【1】PROCESS(blink_process,"Blink");相关于函数的声明 【2】AUTOSTART_PROCESSES(&blink_process);是指该任务自动启动，也可以调用process_start函数启动任务。 AUTOSTART_PROCESSES其实也是一个宏东定义： [cpp] view plaincopy
- #if ! CC_NO_VA_ARGS
- #if AUTOSTART_ENABLE
- #define AUTOSTART_PROCESSES(...) \
- struct process * const autostart_processes[]= {__VA_ARGS__, NULL}
- #else //AUTOSTART_ENABLE
- #define AUTOSTART_PROCESSES(...) \
- extern
int _dummy - #endif //AUTOSTART_ENABLE
- #else
- #error "C compiler must support __VA_ARGS__ macro"
- #endif
要想使用它的话，还需要添加AUTOSTART_ENABLE定义。#define AUTOSTART_ENABLE 1 最后请大家不要忘记LED相关IO口的初始化操作。请查看前文代码。 | 
