這里提供一種4*4矩陣按鍵掃描方案，供參考。
原理分析：
電路圖：
單片機源碼：
- #include<reg52.h>
- typedef unsigned int u16;
- typedef unsigned char u8;
- //定義鍵盤連接的端口
- #define keyboard_px P2
- u8 code key_tab[]={0xEE,0xDE,0xBE,0x7E,0xED,0xDD,0xBD,0x7D,0xEB,0xDB,0xBB,0x7B,0xE7,0xD7,0xB7,0x77};
- //共陰極數碼管0-f編碼
- u8 code seg_tab[]={0x3F,0x06,0x5B,0x4F,0x66,0x6D,0x7D,0x7,0x7F,0x6F,0x77,0x7C,0x39,0x5E,0x79,0x71,0x40};
- //定義數據輸出端口
- #define seg_px P0
- //延時1ms函數（晶振11.0592MHz）
- void delay(u16 num)
- {
- u16 x,y;
- for(x=num; x>0; x--){for(y=113; y>0; y--);}
- }
- //鍵盤掃描函數，輸出數組索引值
- u8 key_scan(void)
- {
- u8 temp1, temp2;
- keyboard_px = 0xf0;
- delay(5);
- if(keyboard_px != 0xf0)
- {
- delay(5);
- if(keyboard_px != 0xf0)
- {
- temp1 = keyboard_px;
- keyboard_px = 0x0f;
- delay(5);
- temp2 = keyboard_px;
- return (temp1|temp2);
- }
- }
- return 0xf0;
- }
- void show(u8 key_code)
- {
- u8 i;
- if (key_code != 0xf0)
- {
- for (i=0; i<16; i++)
- {
- if (key_tab[i] == key_code)
- {
- seg_px = seg_tab[i];
- break;
- }
- }
- }else{
- seg_px = 0x00;
- }
- }
- void main(void)
- {
- keyboard_px = 0xf0;
- seg_px = 0x00;
- while(1)
- {
- show(key_scan());
- }
- }
矩陣鍵盤.rar
(82.47 KB, 下載次數: 56)
2020-3-2 13:53 上傳
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