Protues仿真C51单片机串口通信，发送信息无响应
Protues仿真C51单片机串口通信，发送信息无响应
#include<reg52.h>
#include <math.h>
#define uchar unsigned char
#define uint unsigned int
#define PI 3.14
sbit ADD_A = P1^0;//channel selection signal
sbit ADD_B = P1^1;
sbit ADD_C = P1^2;
sbit START = P1^4;//start signal. When start:0-1, register clear; when start:1-0, AD convertion starts; when AD converting, start remain 0
sbit EOC = P1^5;//EOC=1, convertion is over; EOC=0, convertion is in progress
sbit OE = P1^6;//OE=1, output is available; OE=0, output is disavailable
sbit CLK = P1^7;
sbit C_A = P0^0;
sbit C_B = P0^1;
sbit C_C = P0^2;
sbit C_D = P0^3;
sbit EN = P1^3;
uchar getdata;
uchar test = 1;
uchar flag_serial,temp;
//time delay
void delay_ms(uint t)
{
uint x,y;
for(x = t;x > 0;x--)
for(y = 110;y > 0;y--);
}
//AD channel selection
void AD_Channel_Select(uchar channel)
{
switch(channel)
{
case 0:
ADD_A = 0;
ADD_B = 0;
ADD_C = 0;
break;
case 1:
ADD_A = 1;
ADD_B = 0;
ADD_C = 0;
break;
case 2:
ADD_A = 0;
ADD_B = 1;
ADD_C = 0;
break;
case 3:
ADD_A = 1;
ADD_B = 1;
ADD_C = 0;
break;
case 4:
ADD_A = 0;
ADD_B = 0;
ADD_C = 1;
break;
case 5:
ADD_A = 1;
ADD_B = 0;
ADD_C = 1;
break;
case 6:
ADD_A = 0;
ADD_B = 1;
ADD_C = 1;
break;
case 7:
ADD_A = 1;
ADD_B = 1;
ADD_C = 1;
break;
default:
break;
}
}
void CD_Channel_Select(uchar C_channel)
{
switch(C_channel)
{
case 0:
C_A = 0;
C_B = 0;
C_C = 0;
C_D = 0;
break;
case 1:
C_A = 1;
C_B = 0;
C_C = 0;
C_D = 0;
break;
case 2:
C_A = 0;
C_B = 1;
C_C = 0;
C_D = 0;
break;
case 3:
C_A = 1;
C_B = 1;
C_C = 0;
C_D = 0;
break;
case 4:
C_A = 0;
C_B = 0;
C_C = 1;
C_D = 0;
break;
case 5:
C_A = 1;
C_B = 0;
C_C = 1;
C_D = 0;
break;
case 6:
C_A = 0;
C_B = 1;
C_C = 1;
C_D = 0;
break;
case 7:
C_A = 1;
C_B = 1;
C_C = 1;
C_D = 0;
break;
case 8:
C_A = 0;
C_B = 0;
C_C = 0;
C_D = 1;
break;
case 9:
C_A = 1;
C_B = 0;
C_C = 0;
C_D = 1;
break;
case 10:
C_A = 0;
C_B = 1;
C_C = 0;
C_D = 1;
break;
case 11:
C_A = 1;
C_B = 1;
C_C = 0;
C_D = 1;
break;
case 12:
C_A = 0;
C_B = 0;
C_C = 1;
C_D = 1;
break;
case 13:
C_A = 1;
C_B = 0;
C_C = 1;
C_D = 1;
break;
case 14:
C_A = 0;
C_B = 1;
C_C = 1;
C_D = 1;
break;
case 15:
C_A = 1;
C_B = 1;
C_C = 1;
C_D = 1;
break;
default:
break;
}
}
void ad0809()
{
OE = 1;
START = 0;//start 0809
START = 1;
START = 0;
delay_ms(1);
while(!EOC);//wait for end of convertion
OE = 1;
getdata = P2;//read data from p2
OE = 0;
}
void Timer_Init()
{
TMOD = 0x22;
TH0 = (256-40);
TL0 = (256-40);
ET0 = 1;
TR0 = 1;
}
void Chuankou_Init()
{
TH1 = 0xfd;
TL1 = 0xfd;
TR1 = 1;
EA = 1;
ES = 1;
REN = 1;
SM0 = 0;
SM1 = 1;
}
void T0_CLK() interrupt 1
{
CLK =~ CLK;
}
void ser() interrupt 4
{
RI = 0;
temp = SBUF;
flag_serial = 1;
}
void main()
{
Timer_Init();//timer and SCON initialization
Chuankou_Init();
EN = 0;//make 4067 work
AD_Channel_Select(0);//choose channel of 0809
delay_ms(10);
flag_serial=1;
while(1)
{
uchar i=0;
for(i=0;i<16;i++)
{
CD_Channel_Select(i);
delay_ms(10);
ad0809();
if(flag_serial==1)
{
ES=0;
SBUF=getdata;
while(!TI);
TI=0;
ES=1;
}
}
delay_ms(800);
}
}
仿真接线如下，0809和4067是进行AD转换的
将示波器接到单片机P3.1口，仿真结果如下
请问问题出在哪里？
中断里改变的全局变量，定义的时候加上volatile以防止优化。比如程序里的flag_serial
下面这个
uchar flag_serial,temp;
在前面加上 volatile 试下
volatile uchar flag_serial,temp;
因为取数据的问题，经常碰到变量被莫名优化了，造成变量或者标志位明明置位，但判断条件不成立的问题
```
max232的收发没接到单片机上，不行你就在线仿真，单步运行程序，看是否执行发送那儿，proteus8以下版本支持和keil在线联调
我按你的代码和原理图仿了一下，串口是可以正常发送的。你示波器那个波形可能是发送的0x00?UART发送0x00的波形就是这样的。发个别的数据试试？
双击AT89C52（我使用的芯片）芯片，把下方附加层次模块的勾勾去掉就可以了。