| sbit C1 = P3^3; | |
| sbit C2 = P3^2; | |
| sbit C3 = P3^1; | |
| sbit C4 = P3^0; | |
| unsigned char code led[8] = { | |
| 0xFE, 0xFC, 0xF8, 0xF0, | |
| 0xE0, 0xC0, 0x80, 0x00 | |
| }; | |
| void delayMs(unsigned int i) | |
| { | |
| unsigned char t; | |
| while (i--) | |
| { | |
| for (t = 0; t < 120; t++); | |
| } | |
| } | |
| unsigned char scan(void) | |
| { | |
| unsigned char k = 0; | |
| P3 = 0x7F; | |
| if (C1 == 0) k = 1; | |
| else if (C2 == 0) k = 2; | |
| else if (C3 == 0) k = 3; | |
| else if (C4 == 0) k = 4; | |
| if (k == 0) | |
| { | |
| P3 = 0xBF; | |
| if (C1 == 0) k = 5; | |
| else if (C2 == 0) k = 6; | |
| else if (C3 == 0) k = 7; | |
| else if (C4 == 0) k = 8; | |
| } | |
| P3 = 0xFF; | |
| return k; | |
| } | |
| void main(void) | |
| { | |
| unsigned char k; | |
| P2 = 0xFF; | |
| while (1) | |
| { | |
| k = scan(); | |
| if (k != 0) | |
| { | |
| delayMs(10); | |
| if (scan() == k) | |
| P2 = led[k - 1]; | |
| } | |
| } | |
| } | |