在Atmle Studio6.2的开发环境直接插入开发板。就可直接打开例程。
今天例程简单，通过串口打印一个字符串，然后接收用户的输入字符，每输入一个回显一个
我觉得高难的是初始化函数用了大量的指针：
- */
- static inline void stdio_serial_init(volatile void *usart, const usart_serial_options_t *opt)
- {
- stdio_base = (void *)usart;
- ptr_put = (int (*)(void volatile*,char))&usart_serial_putchar;
- ptr_get = (void (*)(void volatile*,char*))&usart_serial_getchar;
- # if (XMEGA || MEGA_RF)
- usart_serial_init((USART_t *)usart,opt);
- # elif UC3
- usart_serial_init(usart,(usart_serial_options_t *)opt);
- # elif SAM
- usart_serial_init((Usart *)usart,(usart_serial_options_t *)opt);
- # else
- # error Unsupported chip type
- # endif
- # if defined(__GNUC__)
- # if (XMEGA || MEGA_RF)
- // For AVR GCC libc print redirection uses fdevopen.
- fdevopen((int (*)(char, FILE*))(_write),(int (*)(FILE*))(_read));
- # endif
- # if UC3 || SAM
- // For AVR32 and SAM GCC
- // Specify that stdout and stdin should not be buffered.
- setbuf(stdout, NULL);
- setbuf(stdin, NULL);
- // Note: Already the case in IAR's Normal DLIB default configuration
- // and AVR GCC library:
- // - printf() emits one character at a time.
- // - getchar() requests only 1 byte to exit.
- # endif
- # endif
- }
接下来是打印一串字符然后就等待用户输入
- // Print welcome message
- printf("\n\rHello ATMEL World!\n\r");
- // Get and echo a character forever.
- while (true) {
- scanf("%c",(char*)&ch);
- if (ch) {
- printf("%c",(char)ch);
- }
- }
这个例和调用的大量的库函数：
- read.c : System implementation function used by standard library
- * - write.c : System implementation function used by standard library
本例运行如下：
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