[atomthreads] Atomthreads explained

[Andrzej Telszewski]

Hi,

It would be nice if you put some more examples on how to use 
atomthreads. Let's say it would have 3 or 4 threads and some two 
interrupts and the stack sizes explained. I'm novice in threads, so I 
might be asking for too much, if so, then clarify me;)

Also, I'm very interested in using C++ with atom and it seems that it 
works, so maybe you could give some explanation on how to do it 
properly? I attach my test application that uses one C++ object.

Finally, I suggest that AVR_CPU_HZ in atomport.h was defined as:
#define AVR_CPU_HZ F_CPU
and that "atomport-asm.s" was renamed to "atomport-asm.S". Those two 
changes will allow the atomthreads to integrate nicely with WinAVR (or 
with Makefile from WinAVR, as I use it under Linux).

By the way, as you may notice I'm interested in AVR's, but it might change;)

--
Best regards,
Andrzej Telszewski
#include <avr/io.h>
#include "lcd.h"

extern "C" {
#       include "atom.h"
#       include "atomport.h"
#       include "atomtimer.h"
}

#define IDLE_STACK_SIZE_BYTES           128
#define STARTUP_STACK_SIZE_BYTES        64

static uint8_t idle_thread_stack[IDLE_STACK_SIZE_BYTES];

static ATOM_TCB main_tcb;
static void main_thread_func (uint32_t data);

static ATOM_TCB lcd_tcb;
static void lcd_thread_func (uint32_t data);

int main()
{
        if( ATOM_OK == atomOSInit(&idle_thread_stack[IDLE_STACK_SIZE_BYTES - 
1]) )
        {
                avrInitSystemTickTimer();
                
                if( ATOM_OK != atomThreadCreate( &lcd_tcb, 64, lcd_thread_func, 
0, (POINTER)(RAMEND-STARTUP_STACK_SIZE_BYTES-128) ) )
                {
                        goto _ATOM_FAILED;
                }
                
                if( ATOM_OK == atomThreadCreate( &main_tcb, 64, 
main_thread_func, 0, (POINTER)(RAMEND-STARTUP_STACK_SIZE_BYTES)) )
                {
                        atomOSStart();
                }
        }
        
        _ATOM_FAILED:
        while( 1 );
        
        return 0;
}

static void main_thread_func (uint32_t data)
{
        while( 1 )
        {
                PORTB |= _BV(PB0);
                atomTimerDelay( 20 );
                PORTB &= ~_BV(PB0);
                atomTimerDelay( 20 );
        }
}

static void lcd_thread_func (uint32_t data)
{
        uint8_t sec = 35;
        uint8_t min = 41;
        uint8_t hour = 12;
        
        while( 1 )
        {
                if( ++sec == 60 )
                {
                        sec = 0;
                        if( ++min == 60 )
                        {
                                min = 0;
                                if( ++hour == 24 ) hour = 0;
                        }
                }
                
                lcd.clrscr();
                lcd << pad() << (uint8_t)hour << ':' << (uint8_t)min << ':' << 
(uint8_t)sec;
                atomTimerDelay( SYSTEM_TICKS_PER_SEC );
        }
}