Question

如何让单片机随机一个引脚输出高电平

Answer 1

#include<stdlib.h>
#include<reg51.h>
#define uchar unsigned char
uchar rd;
bit flag=0;
void ext0() inerrupt 0
{
rd=(int)24.0*(rand()/(RAND_MAX+1.0))
flag=1;
}
void t0isr() intrrupt 1
{
;
}
main()
{
uchar tmp;
TMOD=0x01;
ET0=1;
TR0=1;
EX0=1;
IT0=1;
EA=1;
srand(TH0*256+TL0);
while(1)
{
if(flag)
{
if(rd<8)P0=0x01<<rd;
if(rd>=8 && rd<16)P1=0x01<<(rd-8);
if(rd>=16)P2=0x01<<(rd-16);
flag=0;
srand(TH0*256+TL0);
}
}
}