使用C语言检测微控制器ATmega328P上的按钮信号

Question

微控制器：ATmega328P

我遇到以下代码的问题。它用于通过连接到PB0的按钮控制LED灯。

有2个州：
 1. state_0 - 所有LED均熄灭  2. state_1 - 所有LED均亮起。

#include <avr/io.h>

int main(void)
{
    DDRB = 0x00;    //set PINB as a input port for receiving PB0 signal
    DDRD = 0xFF;    //set PORTD as a output port for driving the LEDs
    unsigned char state_0 = 0x00;   //all LED bits are off
    unsigned char state_1 = 0xFF;   //all LED bits are on

    PORTD = state_0 //initialize the state  <----Still work here, Not work after this instruction.

    while(1)
    {   
        if(PINB0 == 0 && PORTD == state_0)      //when the button is not pressed and the LEDs are off
        {
            PORTD = state_0;                    //the LED states remain all off 
        }
        else if(PINB0 == 0 && PORTD == state_1) //when the button is not pressed and the LEDs are on
        {
            PORTD = state_1;                    //the LED states remain all on
        }
        else if(PINB0 == 1 && PORTD == state_0) //when the button is pressed and the LEDs are off
        {
            PORTD = state_1;                    //the LED states are turned to all on
        }
        else                                    //when the button is pressed and the LEDs are on
        {
            PORTD = state_0;                    //the LED states are turned to all off
        }
    }
}

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经过一些测试，我发现微控制器无法检测到来自PB0的任何信号。当我直接将Vcc连接到PB0或直接将GND连接到PB0时，我得到相同的结果。当我按下按钮时，没有任何改变。

while(1)
{
    if (PINB0 == 0)
        PORTD = 0x00;
    else
        PORTD = 0xFF;
}

---

以上代码的连接：
不行

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要测试按钮，请尝试以下操作。这是工作，所以botton正常工作

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你知道出了什么问题吗？ 谢谢你的帮助。

Answer 1

问题是你的程序实际上没有检测到状态的变化 - 如果while循环运行得足够快（可能是），即使简短按下按钮也会触发if(PINB0 == 0 && PORTD == state_0)和{{1部分。

考虑添加某种检查状态 - 如下所示：

else

（对于糟糕的缩进感到抱歉，很难在这里得到它）