K1_K4分组控制LED.rar

#include <avr/io.h> #include <util/delay.h> int main(void) { unsigned char k,Recent_Key; PORTB = 0xFF; DDRB = 0x00; PORTC = 0xFF; DDRC = 0xFF; while(1) { Recent_Key = PINB; if(Recent_Key != 0xFF) { _delay_ms(10); if(Recent_Key != PINB) continue; Recent_Key = ~Recent_Key; k = 0; while(Recent_Key != 0) { k++; Recent_Key >>= 1; } switch(k) { case 1:if(PORTC == 0x00) PORTC = 0xFF; PORTC <<= 1; _delay_ms(300); break; case 2:PORTC = 0xF0; break; case 3:PORTC = 0x0F; break; case 4:PORTC = 0xFF; } } } }