下面是在P1口接4X3矩陣鍵盤的驅動程序,供妳參考。上拉電阻也可以不用.
code?U8?kcode[]={0xb7,0xbe,0xde,0xee,0xbd,0xdd,0xed,0xbb,0xdb,0xeb,0xd7,0xe7};
//反轉碼對應鍵值? 0 1 2 3 4 5 6 7 8 9 A B
U8?key(void)
{?U8?a,r?=?0xff;
delay_ms(20);?//?延時20毫秒,消除按鍵抖動 if(P1?==?0xf0)?goto?rn; a?=?P1; P1?=?a?|?0x0f; delay_ms(20); a?=?P1; for?(r?=?0;r?<=?11;r++) { if(a?==?kcode[r])?break; };rn:?P1?=?0xf0;
return?r;}