The microc don't do anothers tasks

Altera_Forum · ‎03-14-2013

Hi, I was reading the example code "hello_ucosii.c", but when I modify the code he made only the task1. My code modified is:

# include <stdio.h># include "includes.h"# include "system.h"# include <unistd.h># include "altera_avalon_pio_regs.h"# include "alt_types.h"
/* Definition of Task Stacks */# define   TASK_STACKSIZE       2048
OS_STK    task1_stk;
OS_STK    task2_stk;
/* Definition of Task Priorities */
# define TASK1_PRIORITY      1# define TASK2_PRIORITY      2
/*Subroutine for wait a necessary time for each level of PWM signal*/
int count(float n, float f)
{
    int i;
    float a, x;
    x=(1/f)*2000000;
    a=n*x;
        for(i=1; i<=a; i++)
        {
            x=0;
        }
    return n;
}
/* Gerate a PWM Signal */
void task1(void* pdata)
{
    int signal, control;
    float f, n;
    f=100;//22Hz in practice
    while(1)
    {
           control=IORD_ALTERA_AVALON_PIO_DATA(DUTY_PIO_BASE);
           
           if(control==0x0)
           {
                            signal=0x0;
                            IOWR_ALTERA_AVALON_PIO_DATA(PWM_PIO_BASE, signal);
           }
                            
           if(control==0x1)
           {
                            n=0.25*(1/f);
                            signal=0x1;
                            IOWR_ALTERA_AVALON_PIO_DATA(PWM_PIO_BASE, signal);
                            n=count(n,f);
                            n=(1-0.25)*(1/f);
                            signal=0x0;
                            IOWR_ALTERA_AVALON_PIO_DATA(PWM_PIO_BASE, signal);
                            n=count(n,f);
            }
                            
           if(control==0x3)
           {
                            n=0.50*(1/f);
                            signal=0x1;
                            IOWR_ALTERA_AVALON_PIO_DATA(PWM_PIO_BASE, signal);
                            n=count(n,f);
                            n=(1-0.50)*(1/f);
                            signal=0x0;
                            IOWR_ALTERA_AVALON_PIO_DATA(PWM_PIO_BASE, signal);
                            n=count(n,f);
           }
                            
           if(control==0x7)
           {
                            n=0.75*(1/f);
                            signal=0x1;
                            IOWR_ALTERA_AVALON_PIO_DATA(PWM_PIO_BASE, signal);
                            n=count(n,f);
                            n=(1-0.75)*(1/f);
                            signal=0x0;
                            IOWR_ALTERA_AVALON_PIO_DATA(PWM_PIO_BASE, signal);
                            n=count(n,f);
            }
                            
           if(control==0xf)
           {
                            signal=0x1;
                            IOWR_ALTERA_AVALON_PIO_DATA(PWM_PIO_BASE, signal);
           }
                            
     }             
     
}
/* Prints "Hello World" and sleeps for three seconds */
void task2(void* pdata)
{
  while (1)
  { 
    printf("Hello from task2\n");
    OSTimeDlyHMSM(0, 0, 3, 0);
  }
}
/* The main function creates two task and starts multi-tasking */
int main(void)
{
  
  OSTaskCreateExt(task1,
                  NULL,
                  (void *)&task1_stk,
                  TASK1_PRIORITY,
                  TASK1_PRIORITY,
                  task1_stk,
                  TASK_STACKSIZE,
                  NULL,
                  0);
              
               
  OSTaskCreateExt(task2,
                  NULL,
                  (void *)&task2_stk,
                  TASK2_PRIORITY,
                  TASK2_PRIORITY,
                  task2_stk,
                  TASK_STACKSIZE,
                  NULL,
                  0);
  OSStart();
  return 0;
}

I'm use Quartus II 9.1 sp2 web edition, Nios II EDS 9.1 sp2 and the DE2 board series.

Thank you in advance

Altera_Forum · ‎03-14-2013

Your tasks probably need to explicilty sleep, otherwise the current task will run forever.

Even if your tasks had the same priority you'll need to do some call in order to get the other task to run.

Altera_Forum · ‎03-14-2013

The highest priority task runs until it blocks.

In your code snippet, "TASK1" has the highest priority but never blocks, while "TASK2" has lower priority but sleeps for 3 seconds at a time.

Switch the priorities around and try again.

Altera_Forum · ‎03-15-2013

I change the priority of the tasks and worked, but I wish that the two tasks were performed simultaneously. Is that possible?

Altera_Forum · ‎03-15-2013

Well, "simultaneously" is not possible.

If you want round-robin scheduling ("timeslicing"), it is not available in version II of this RTOS, but it is available in version III.

The snippet you posted looks like a simple polling loop. If you are simply saying you have many of such polling loops, just use one task and execute the polling loops one after the other.

e.g.

while(1) {

poll_blockA();

poll_blockB();

poll_blockC();

}

Other than that, you are left to crafting your own application level scheduling using e.g. mutex or messages to get your polling to happen in the order you would like. Or, you could start using interrupts and only run your polling when your inputs change, for example.