Atmega 328 代码问题 | 我正在尝试创建 4 个场景

Question

In the following code I am trying to create 4 scenarios

I) Red Led blinks at the specified rate when button 1 is pressed

II) Green Led blinks at the specified rate when button 2 is pressed

III) Both Led blinks at the specified rate when button 3 is pressed

IV) when more than 1 button is pressed Do nothing.

Scenario I,II,III works but I am having trouble for IV

#include <avr/io.h>
#include <util/delay.h>
#define DURATION 40

int main(void){
    DDRD = 1<<DDD7|1<<DDD6;// D7 as output; other pins input 
    PORTD = 1<<PORTD4|1<<PORTD2|1<<PORTD5;  // Set internal pullup resistor on D4

    while(1){

        if  ((PIND & (1<<PIND2)) == 0){ // PIND4=0 when pressed
            PORTD ^= (1<<PORTD6);
            _delay_ms(DURATION);}
        else{
              PORTD &= ~(1<<PORTD6);
              }
        if  ((PIND & (1<<PIND4)) == 0){ // PIND4=0 when pressed
            PORTD ^= (1<<PORTD7);
            _delay_ms(DURATION);}
        else {
            PORTD &= ~(1<<PORTD7);}// When button isn't pressed
        if ((PIND & (1<<PIND5)) == 0){
           _delay_ms(DURATION);
           PORTD ^= (1<<PORTD6);
           _delay_ms(DURATION);
           PORTD ^= (1<<PORTD7);
           _delay_ms(DURATION);
          }
        else {
            PORTD &= ~(1<<PORTD6)|~(1<<PORTD7);
        }
        if((PIND & (1<<PIND5)|(1<<PIND2)|(1<<PIND4)) == 0){
          PORTD &= ~(1<<PORTD6)|~(1<<PORTD7);
          }
        }
       return(0);
}

Answer 1

change PORTD &= ~(1<<PORTD6)|~(1<<PORTD7); to PORTD &= ~((1<<PORTD6)|(1<<PORTD7)); because result of first expression is 0xFF