在純 C 中在 atmega328 上設置中斷

Question

我目前正在開發一個 Arduino Uno 開發板，我試圖在不使用 Arduino 庫的情況下用純C編寫它。

我正在工作的項目應該是這樣的：

• 將 LED PB0至BP7設置為ON和OFF 。

• 在連接到按鈕的 PD2 上設置中斷。

• 按下按鈕時，LED 應停止（暫停）。

• 當再次按下按鈕時，LED 應再次ON
  從最后一個OFF LED 開始。

更准確地說：

• 函數play()被調用
• LED 開始一個接一個地閃爍
• 如果我按下按鈕play()函數應該停止

這意味着，如果連接到PB3的 LED 上次 LED 亮起，當我再次按下按鈕時，函數play()應該從PB4繼續。

這是我到目前為止所擁有的：

#ifndef F_CPU
#define F_CPU 16000000UL
#endif

#include <avr/io.h>
#include <avr/interrupt.h>
#include <util/delay.h>

void play( void );

volatile uint8_t buttonWasPressed = 0;
const unsigned char LEDS[] = { PB0, PB1, PB2, PB3, PB4, PB5 };

int main(void)
{
    DDRB = 0xFF;  /// Set PORTB as OUTPUT

    DDRD  |=  ( 1 << PD7 );     /// Set PIN7 IN DDRD as INPUT
    PORTD &= ~( 1 << PD7 );     /// Set PIN7 on PORTD to LOW
    DDRD  &= ~( 1 << PD2 );     // Clear the PD2 pin and set PD2 (PCINT0 pin) now as input
    PORTD |= (1 << PD2);        // Set PIN PD2 as INPUT with pull-up enabled

    EICRA |= (1 << ISC00);      // set INT0 to trigger on ANY logic change
    EIMSK |= (1 << INT0);       // Turns on INT0
    sei();                      // turn on interrupts

    while(1)
    {
        play();
    }
}

ISR (INT0_vect)
{

    uint8_t buttonState = PIND & ( 1 << PD2 );
    if ( buttonState )
    {
        if ( buttonWasPressed == 0 )
        {
            PORTD ^= ( 1 << PD7 );  /// SET PIN 4 IN PORT B TO LOW
            _delay_ms( 200 );
            buttonWasPressed = 1;   /// update button state
        }
    }
    else                            /// The button is not pressed
    {
        buttonWasPressed = 0;       /// Update the button state
    }
}

void play( void )
{
    for ( uint8_t i = 0 ; i < 6 ; i++ )
    {
        PORTB |= ( 1 << LEDS[i] );  ///Turn LED ON
        _delay_ms( 250 );
        PORTB &= ~( 1 << LEDS[i] ); ///Turn LED OFF
        _delay_ms( 250 );
    }
}

此時，函數play()將永遠運行，如果我按下按鈕，連接到PD7的 LED 會ON和OFF 。

Answer 1

嘗試這樣的事情。

#ifndef F_CPU
#define F_CPU 16000000UL
#endif

#include <avr/io.h>
#include <avr/interrupt.h>
#include <util/delay.h>

void play( unsigned int a );
ISR (INT0_vect);

volatile uint8_t buttonWasPressed = 0;
const unsigned char LEDS[] = { PB0, PB1, PB2, PB3, PB4, PB5 };
unsigned int ledNum = 0;

int main(void)
{
    DDRB = 0xFF;  /// Set PORTD as OUTPUT

    DDRD  |=  ( 1 << PD7 );     /// Set PIN7 IN DDRD as INPUT
    PORTD &= ~( 1 << PD7 );     /// Set PIN7 on PORTD to LOW
    DDRD  &= ~( 1 << PD2 );     // Clear the PD2 pin and set PD2 (PCINT0 pin) now as input
    PORTD |= (1 << PD2);        // Set PIN PD2 as INPUT with pull-up enabled

    EICRA |= (1 << ISC00);      // set INT0 to trigger on ANY logic change
    EIMSK |= (1 << INT0);       // Turns on INT0
    sei();                      // turn on interrupts

    while(1)
    {
        if(buttonWasPressed == 1)
            play(ledNum);

    }
}

ISR (INT0_vect)
{

    uint8_t buttonState = PIND & ( 1 << PD2 );
    if ( buttonState )
    {
        if ( buttonWasPressed == 0 )
        {
            PORTD ^= ( 1 << PD7 );  /// SET PIN 4 IN PORT B TO LOW
            _delay_ms( 200 );
            buttonWasPressed = 1;   /// update button state
        }
    }
    else                            /// The button is not pressed
    {
        buttonWasPressed = 0;       /// Update the button state
    }
}

void play( unsigned int a )
{
    for ( uint8_t i = a ; i < 6 ; i++ )
    {
        PORTB |= ( 1 << LEDS[i] );  ///Turn LED ON
        _delay_ms( 250 );
        PORTB &= ~( 1 << LEDS[i] ); ///Turn LED OFF
        _delay_ms( 250 );
        ledNum=i;
    }
}

通過定義一個變量來保存它所在的 LED，然后每當它恢復時，它將從最后一個點亮的 LED 開始。 一探究竟。 有事就換。 我只是給出了想法。 希望能幫助到你 ：）

Answer 2

我在@Althaf1467 的幫助下設法修復了它。

工作代碼是：

#ifndef F_CPU
#define F_CPU 16000000UL
#endif

#include <avr/io.h>
#include <avr/interrupt.h>
#include <util/delay.h>

#define LEDS_LENGTH 6

void play( void );

volatile uint8_t state = 0 ;
const unsigned char LEDS[] = { PB0, PB1, PB2, PB3, PB4, PB5 };

int main( void )
{
    DDRB = 0xFF;                    /// Set PORTD as OUTPUT

    DDRD  |=  ( 1UL << PD7   );     /// Set PIN7 IN DDRD as INPUT
    PORTD &= ~( 1UL << PD7   );     /// Set PIN7 on PORTD to LOW
    DDRD  &= ~( 1UL << PD2   );     /// Clear the PD2 pin and set PD2 (PCINT0 pin) now as input
    PORTD |=  ( 1UL << PD2   );     /// Set PIN PD2 as INPUT with pull-up enabled

    EICRA |=  ( 1UL << ISC00 );     /// set INT0 to trigger on ANY logic change
    EIMSK |=  ( 1UL << INT0  );     /// Turns on INT0
    sei();                          /// turn on interrupts

    while(1)
    {
        play();
    }
}

ISR ( INT0_vect )
{
    if ( PIND & ( 1UL << PD2 ) )
    {
        PORTD ^= ( 1UL << PD7 );    /// SET PIN 4 IN PORT B TO LOW
        state ^= ( 1 << 0 );        /// Swap the Buton State from 0 to 1 and back to 0 ...
        _delay_ms( 500 );
    }
}

void play( void )
{
    static uint8_t step = 0;
    while( step < LEDS_LENGTH )
    {
        if ( state == 1 )
        {
            break;
        }
        PORTB |=  ( 1UL << LEDS[ step ] );  /// Turn LED ON
        _delay_ms( 250 );

        PORTB &= ~( 1UL << LEDS[ step ] );  /// Turn LED OFF
        _delay_ms( 250 );

        step++;
    }

    if ( step == LEDS_LENGTH )
    {
        step = 0;
    }
}