| unsigned char i = 0; | |
| void timer(void) interrupt 1 | |
| { | |
| TH0 = 0x3C; | |
| TL0 = 0xB0; | |
| i++; | |
| if (i == 20) | |
| { | |
| i = 0; | |
| if (P2 == 0xF0) | |
| P2 = 0x0F; | |
| else | |
| P2 = 0xF0; | |
| } | |
| } | |
| void main(void) | |
| { | |
| P2 = 0xF0; | |
| TMOD = 0x01; | |
| TH0 = 0x3C; | |
| TL0 = 0xB0; | |
| ET0 = 1; | |
| EA = 1; | |
| TR0 = 1; | |
| while (1); | |
| } | |