回顾一下上一篇
简单的实现GD32F150R8 与Labview 之间的通讯，代码如下
switch (cGetChar)
{.......................
}
cGetChar 大小决定任务的复杂性与扩展性。这里意味着最多有且仅有128种的扩展，并且也不利于数据通信。并且在可读性上很差在日后维护性上带来很大的不足。
采用command line 进行扩展。其实很简单，只不过是性字符串的比较
利于命令"set led %d\r\n"，却对led显示的模式进行设置
但串口接收到\r\n时，对command 进行分析，并且与GD32F150R8中注册的command进行寻找配对
当找到时，调用其对应的函数，进行解析。而main函数就变得很简单
关键代码如下：
- int main(void)
- {
- //int i;
- char cGetChar;
- EVB_LEDConfig();
- EVB_Uart2Config();
- PRINTF("\r\nLabview & GD32F150\r\n");
- while(1)
- {
- run_cmd();
- }
- }
- char *
- get_line (char *line)
- {
- int pos;
- int ch;
- pos = 0;
- ch = (int)uif_in_char();
- while ( (ch != 0x0D /* CR */) &&
- (ch != 0x0A /* LF/NL */) &&
- (pos < UIF_MAX_LINE))
- {
- switch (ch)
- {
- case 0x08: /* Backspace */
- case 0x7F: /* Delete */
- if (pos > 0)
- {
- pos -= 1;
- uif_out_char(0x08); /* backspace */
- uif_out_char(' ');
- uif_out_char(0x08); /* backspace */
- }
- break;
- default:
- if ((pos+1) < UIF_MAX_LINE)
- {
- if ((ch > 0x1f) && (ch < 0x80))
- {
- line[pos++] = (char)ch;
- uif_out_char((char)ch);
- }
- }
- break;
- }
- ch = (int)uif_in_char();
- }
- line[pos] = '\0';
- uif_out_char(0x0D); /* CR \r 回车*/
- uif_out_char(0x0A); /* LF \n 换行*/
- return line;
- }
- void
- run_cmd (void)
- {
- /*
- * Global array of pointers to emulate C argc,argv interface
- */
- int argc;
- char *argv[UIF_MAX_ARGS + 1]; /* one extra for null terminator */
- get_line(cmdline1);
- argc = make_argv(cmdline1,argv);
- //if (!(argc = make_argv(cmdline1,argv)))
- if( argc==0 )
- {
- /* no command entered, just a blank line */
- strcpy(cmdline1,cmdline2);
- argc = make_argv(cmdline1,argv);
- }
- cmdline2[0] = '\0';
- if (argc)
- {
- int i;
- for (i = 0; i < UIF_NUM_CMD; i++)
- {
- if (strcasecmp(UIF_CMDTAB.cmd,argv[0]) == 0)
- {
- if (((argc-1) >= UIF_CMDTAB.min_args) &&
- ((argc-1) <= UIF_CMDTAB.max_args))
- {
- if (UIF_CMDTAB.flags & UIF_CMD_FLAG_REPEAT)
- {
- strcpy(cmdline2,argv[0]);
- }
- UIF_CMDTAB.func(argc,argv);
- return;
- }
- else
- {
- uif_printf(SYNTAX,argv[0]);
- return;
- }
- }
- }
- uif_printf(INVCMD,argv[0]);
- uif_printf(HELPMSG);
- }
- }
{"led",0,1,uif_cmd_led,"set led"}
};
进行不断的扩展，就能实现很复杂的响应
- void
- uif_cmd_led (int argc, char **argv)
- {
- int success = false;
- uint32 data =0;
- (void)argc;
- (void)argv;
- data = get_value(argv[2],&success,10);
- switch (data)
- {
- case 0:
- EVB_LEDControl(LED1, LED_OFF);
- EVB_LEDControl(LED2, LED_OFF);
- break;
- case 1:
- EVB_LEDControl(LED1, LED_ON);
- EVB_LEDControl(LED2, LED_OFF);
- break;
- case 2:
- EVB_LEDControl(LED1, LED_OFF);
- EVB_LEDControl(LED2, LED_ON);
- break;
- case 3:
- EVB_LEDControl(LED1, LED_ON);
- EVB_LEDControl(LED2, LED_ON);
- break;
- default:
- break;
- }
- }
- UIF_SETCMD UIF_SETCMDTAB[]={
- {"led",0,1,uif_cmd_led,"set led"}
- };
- const int UIF_NUM_SETCMD = UIF_SETCMDTAB_SIZE;
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