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events_pend tirtos cc26xx

Siarhei Belafost
Prodigy 200 points
Other Parts Discussed in Thread: SYSBIOS
Hello, i wanna use event in my project and its doesnt work
help me please



#include <xdc/std.h>
#include <xdc/runtime/System.h>

/* BIOS Header files */
#include <ti/sysbios/BIOS.h>
#include <ti/sysbios/knl/Clock.h>
#include <ti/sysbios/knl/Task.h>
#include <ti/sysbios/knl/Event.h>
#include <xdc/cfg/global.h>
#include <xdc/runtime/Error.h>


#include "Board.h"

#define TASKSTACKSIZE   768

Task_Struct task0Struct;
Char task0Stack[TASKSTACKSIZE];
Task_Handle firstTask;
Event_Handle myEvent;


Void firstFxn(UArg a0, UArg a1){
		uint32_t i = 0;
	    while(1){
	    	i++;
	    	System_flush();
	    	System_printf(" %d", i);
	    	if(i==5){
	    		Event_post(myEvent, Event_Id_00);
	    	}
			Task_sleep(1000000 / Clock_tickPeriod);
	    }
}



void secondFxn(void){
	UInt evt;
	while(1){
	evt = Event_pend(myEvent, Event_Id_NONE, Event_Id_00, BIOS_NO_WAIT);
	System_printf("Timeout expired for Event_pend()\n");
	if (evt == 0) {
		 System_flush();
		 System_printf(" 111111111");
	            break;
	        }

	if (evt & Event_Id_00) {
				 System_flush();
				 System_printf(" 22222222222");
		}
	}
}


int main(void)
{

	Error_Block eb;
	Error_init(&eb);
	myEvent = Event_create(NULL, &eb);
    Task_Params taskParams;
    Board_initGeneral();

    	Task_Params_init(&taskParams);
        taskParams.stackSize = TASKSTACKSIZE;
        taskParams.stack = &task0Stack;
        taskParams.priority = 1;
        taskParams.instance->name = "firstFxn";
        Task_construct(&task0Struct, (Task_FuncPtr)firstFxn, &taskParams, NULL);
        firstTask = Task_handle(&task0Struct);

    BIOS_start();
    return (0);
}

  • 0
    TI__Guru* 96960 points
    What exactly is not working? Does it build? Note: you need to add the following into the .cfg file.
    var Event = xdc.useModule('ti.sysbios.knl.Event');

    Also, I don't see where you are calling the secondFxn. If it is being called somewhere else, why are you using BIOS_NO_WAIT. This is basically just polling. Part of the advantage of the Event module is the ability to block on multiple things instead of polling.

    Todd
  • 0 in reply to ToddMullanix
    Prodigy 200 points
    1) - i have no cfg file
    2) i dont wanna calling secondFxn, i want starting it when i post myEvent
    3) i using NO_WAIT because i want 2 tasks at the same time working
  • 0 in reply to Siarhei Belafost
    Mastermind 8415 points

    Actually, you want the secondFxn running and pending (waiting for an event to occur).

    Here's the sequence of events that need to occur for your code to work:

    1. Your firstFxn and secondFxn will start when you create them.
    2. Your secondFxn will stop at Event_pend because no events have been recorded yet (control will be given to firstFxn)
    3. firstFxn will eventually execute Event_post (at this time, secondFxn will go into Ready State)
    4. Depending on the priorities of your task, firstFxn will either release control to secondFxn or continue to Task_sleep. No matter what happens, firstFxn will eventually give up control.
    5. SecondFxn will regain control and exit the Event_pend (since the event it was watiing on occurred). The code below the Event_pend will execute once and stop again when it returns to the same Event_pend.
    6. firstFxn will wake up when the Task_sleep delay has expired.
    7. Go back to step 3

    So you need to create both tasks. And you have to use BIOS_WAIT_FOREVER if you want your secondFxn task to wait until the event occurs. Any other delay parameter that you pass to Event_pend (or any other blocking module with a delay) is normally used for error handling in case your program hangs. If a timeout occurs before the event was triggered, the Event_pend function will return False and

    You can actually use this to check which event caused the Event_pend to exit (the awaited event was posted or timeout) 

    if (Event_pend(... insert parameters and timeout here ... )
{
  // Event occurred
  // Do your stuff here
}
else
{
 // handle timeout here (optional)
}

  • 0 in reply to Michel Solecki
    TI__Guru* 96960 points
    I've marked Michel's response as "Verify Answer". If you feel this did not answer your question, please reject it and post a follow-up reply.

    Todd