按鍵 連續與不連續

版權聲明：轉載請註明作者和鏈接 https://blog.csdn.net/Hola_ya/article/details/81204012

int key_scan(mode);

int main()
{
    int key = 0;
    while(1)
    {
        while((key = key_scan(x)))  //掃描按鍵。x爲0或者1
        {
            switch(key)
            {
                case 1:
                    //to do something
                    break;
                case 2:
                    //to do something
                    break;
                .....
            }
        }
    }
}
/* @func  掃描按鍵
 * @param mode 1:支持連按  0:不支持連按
 * @ret   0:未有按鍵按下  其他值表示按鍵的代碼
 */
int key_scan(mode)
{
    static unsigned char key_up = 1;
    if(mode) key_up = 1;//支持連按

    if(key_up && KEY1 == 0)//KEY1爲讀取按鍵爲上拉GPIO口的值，按下時爲0
    {
        delay_ms(5);
        key_up = 0;
        if(KEY1 == 0)
        {
            return 1;//按鍵的編號
        }
    }
    else if(KEY0 == 1)//KEY0未按下
        key_up = 1; 
    return 0;
}