[Wio Terminal开发板测评]+RTOS操作系统测试

jinglixixi

Wio终端不但支持裸机运行，还为其配置了RTOS操作系统。

利用所提供的例程可测试其性能，并可学习其编程思想并加以应用。

该例程含有2个线程，即线程A和线程B，相应的程序内容如下：

1. //*****************************************************************
   
2. // Create a thread that prints out A to the screen every two seconds
   
3. // this task will delete its self after printing out afew messages
   
4. //*****************************************************************
   
5. static void threadA(void* pvParameters) {
   
6. SERIAL.println("Thread A: Started");
   
7. for (int x = 0; x < 20; ++x) {
   
8. SERIAL.print("A");
   
9. delay(500);
   
10. }
    
11. // delete ourselves.
    
12. // Have to call this or the system crashes when you reach the end bracket and then get scheduled.
    
13. SERIAL.println("Thread A: Deleting");
    
14. vTaskDelete(NULL);
    
15. }
    
16. 
    
17. //*****************************************************************
    
18. // Create a thread that prints out B to the screen every second
    
19. // this task will run forever
    
20. //*****************************************************************
    
21. static void threadB(void* pvParameters) {
    
22. SERIAL.println("Thread B: Started");
    
23. while (1) {
    
24. SERIAL.println("B");
    
25. delay(2000);
    
26. }
    
27. }

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其中，线程A的作用是通过延时来打印输出字符“A”，以表示是线程A的处理；而线程B的作用也与其基本相同，所打印输出的是字符“B”，并实行换行。两者最大的区别在于延时值的不同，其中线程A的打印间隔是500毫秒，而线程B的打印间隔是2000毫秒，这样将就导致其输出时出现出交叠的情况。

为监控线程的运行，其任务监视器的程序为:

1. //*****************************************************************
   
2. // Task will periodicallt print out useful information about the tasks running
   
3. // Is a useful tool to help figure out stack sizes being used
   
4. //*****************************************************************
   
5. void taskMonitor(void* pvParameters) {
   
6. int x;
   
7. int measurement;
   
8. SERIAL.println("Task Monitor: Started");
   
9. // run this task afew times before exiting forever
   
10. for (x = 0; x < 10; ++x) {
    
11. SERIAL.println("");
    
12. SERIAL.println("******************************");
    
13. SERIAL.println("[Stacks Free Bytes Remaining] ");
    
14. measurement = uxTaskGetStackHighWaterMark(Handle_aTask);
    
15. SERIAL.print("Thread A: ");
    
16. SERIAL.println(measurement);
    
17. measurement = uxTaskGetStackHighWaterMark(Handle_bTask);
    
18. SERIAL.print("Thread B: ");
    
19. SERIAL.println(measurement);
    
20. measurement = uxTaskGetStackHighWaterMark(Handle_monitorTask);
    
21. SERIAL.print("Monitor Stack: ");
    
22. SERIAL.println(measurement);
    
23. SERIAL.println("******************************");
    
24. delay(10000); // print every 10 seconds
    
25. }
    
26. // delete ourselves.
    
27. // Have to call this or the system crashes when you reach the end bracket and then get scheduled.
    
28. SERIAL.println("Task Monitor: Deleting");
    
29. vTaskDelete(NULL);
    
30. }

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状态配置和循环程序为：

1. void setup() {
   
2. SERIAL.begin(115200);
   
3. vNopDelayMS(1000); // prevents usb driver crash on startup, do not omit this
   
4. while (!SERIAL) ;  // Wait for serial terminal to open port before starting program
   
5. SERIAL.println("");
   
6. SERIAL.println("******************************");
   
7. SERIAL.println("        Program start         ");
   
8. SERIAL.println("******************************");
   
9. // Set the led the rtos will blink when we have a fatal rtos error
   
10. // RTOS also Needs to know if high/low is the state that turns on the led.
    
11. // Error Blink Codes:
    
12. //    3 blinks - Fatal Rtos Error, something bad happened. Think really hard about what you just changed.
    
13. //    2 blinks - Malloc Failed, Happens when you couldn't create a rtos object.
    
14. //               Probably ran out of heap.
    
15. //    1 blink  - Stack overflow, Task needs more bytes defined for its stack!
    
16. //               Use the taskMonitor thread to help gauge how much more you need
    
17. vSetErrorLed(ERROR_LED_PIN, ERROR_LED_LIGHTUP_STATE);
    
18. // Create the threads that will be managed by the rtos
    
19. // Sets the stack size and priority of each task
    
20. // Also initializes a handler pointer to each task, which are important to communicate with and retrieve info from tasks
    
21. xTaskCreate(threadA,     "Task A",       256, NULL, tskIDLE_PRIORITY + 3, &Handle_aTask);
    
22. xTaskCreate(threadB,     "Task B",       256, NULL, tskIDLE_PRIORITY + 2, &Handle_bTask);
    
23. xTaskCreate(taskMonitor, "Task Monitor", 256, NULL, tskIDLE_PRIORITY + 1, &Handle_monitorTask);
    
24. // Start the RTOS, this function will never return and will schedule the tasks.
    
25. vTaskStartScheduler();
    
26. while(1);
    
27. }
    
28. 
    
29. void loop() {
    
30. }

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经程序的编译上传，其结果如图1和图2所示。

由于线程A的打印间隔是500毫秒，而线程B的打印间隔是2000毫秒且换行，故每打印4个字符“A”,打印1个字符“B”,且自动换行（2000/500=4 --> AAAAB）。

仿此，我们可以设计自己的并行程度要求较高的线程任务。

                              

图1 程序编译与上传

图2 运行效果