led_swing.c

ARM入门的好帮手.包含了从简单到相对较复杂的程序.

//*--------------------------------------------------------------------------------------
//*      ATMEL Microcontroller Software Support  -  ROUSSET  -
//*--------------------------------------------------------------------------------------
//* The software is delivered "AS IS" without warranty or condition of any
//* kind, either express, implied or statutory. This includes without
//* limitation any warranty or condition with respect to merchantability or
//* fitness for any particular purpose, or against the infringements of
//* intellectual property rights of others.
//*--------------------------------------------------------------------------------------
//* File Name           : led_swing.c
//* Object              : Led Swing for the AT91EB42
//*
//* 1.0 03/10/01 PFi    : Creation
//*--------------------------------------------------------------------------------------
/****************************************************************************************
* Information : If the "SEMIHOSTING" FLAG is set, when the debugger (ARM SDT or ARM ADS)
* is started * you have to set "$top_of_memory=0x2040000" in the Debugger Internals window
*****************************************************************************************/

#ifdef SEMIHOSTING
#include <stdio.h>
#endif

#include "parts/m42800/lib_m42800.h"
#include "drivers/capture/capture.h"
#include "drivers/wait/wait.h"
#include "targets/eb42/eb42.h"

extern void wake_up_handler (void) ;

/* Global Variable */
WaitDesc wait_desc = { &TC0_DESC, 0, 0, WAIT_DELAY, wake_up_handler } ;
u_int   LedSpeed ;

//*--------------------------------------------------------------------------------------
//* Function Name       : change_speed
//* Object              : Adjust led speed depending on SW1 and SW2
//* Input Parameters    : none
//* Output Parameters   : none
//*--------------------------------------------------------------------------------------
void change_speed ( void )
//* Begin
{
    u_int status = at91_pio_read (&PIOB_DESC) ;
    if (( status & (1<<PIO_SW1) ) == 0 )
    {
        if ( LedSpeed > 10000 ) LedSpeed -=1000 ;
    }
    if (( status & (1<<PIO_SW3) ) == 0 )
    {
        if ( LedSpeed < 2000000 ) LedSpeed +=1000 ;
    }
}
//* End

//*--------------------------------------------------------------------------------------
//* Function Name       : main
//* Object              : Main function of the led swing
//* Input Parameters    : none
//* Output Parameters   : True
//*--------------------------------------------------------------------------------------
int main( void )
//* Begin
{
    u_int   loop_count = 0 ;
    u_int   i ;
    LedSpeed = 80000 ;

    //* -- Set up PIO
    at91_pio_open ( &PIOB_DESC, LED_MASK, PIO_OUTPUT ) ;
    at91_pio_write (&PIOB_DESC, LED_MASK, LED_OFF ) ;


    //* Detect Master Clock
    wait_desc.mcki_khz = 32768 ;

    //* Loop forever
    for (;;)
    {
        //* Once a Shot on each led
        for ( i=LED1 ; i <= LED8 ; i<<=1 )
        {
            change_speed () ;
            at91_pio_write (&PIOB_DESC, i, LED_ON ) ;
            wait_desc.period = LedSpeed ;
            at91_wait_open ( &wait_desc ) ;
            at91_pio_write (&PIOB_DESC, i, LED_OFF ) ;
        }
        //* Once a Shot on each led
        for ( i=LED8 ; i >= LED1 ; i>>=1 )
        {
            change_speed () ;
            at91_pio_write (&PIOB_DESC, i, LED_ON ) ;
            at91_wait_open ( &wait_desc ) ;
            at91_pio_write (&PIOB_DESC, i, LED_OFF ) ;
        }
#ifdef SEMIHOSTING
       printf ( "Loop %d\n", loop_count ) ;
#endif
        loop_count ++ ;

    }
    return(TRUE);
//* End
}