程序调试后总出现如下错误，请高手指教

只看该作者 · 2022-2-7 19:00

11-2.C(40): error C231: 'keyscan_num': redefinition
11-2.C(41): error C141: syntax error near 'return'
11-2.C(41): error C231: 'keyscan_num': redefinition
11-2.C(42): error C141: syntax error near '}'
程序如下：
#include<reg52.h>
sbit wr=P3^6;
sbit rd=P3^2;
sbit key0=P1^0; //定义P1.0脚的按键为正弦波键key0
sbit key1=P1^1; //定义P1.1脚的按键为方波键key1
sbit key2=P1^2;          //定义P1.2脚的按键为三角波键key2
sbit key3=P1^3; //定义P1.3脚的按键为梯形波键key3
sbit key4=P1^4; //定义P1.3脚的按键为锯齿波键key4
unsigned char flag;
unsigned char  const code  //以下为正弦波采样点数组256个数据
SIN_code[256]={0x80,0x83,0x86,0x89,0x8c,0x8f,0x92,0x95,0x98,0x9c,0x9f,0xa2,0xa5,0xa8,0xab,0xae,0xb0,0xb3,0xb6,0xb9,0xbc,0xbf,0xc1,0xc4,0xc7,0xc9,0xcc,0xce,0xd1,0xd3,0xd5,0xd8,0xda,0xdc,0xde,0xe0,0xe2,0xe4,0xe6,0xe8,0xea,0xec,0xed,0xef,0xf0,0xf2,0xf3,0xf4,0xf6,0xf7,0xf8,0xf9,0xfa,0xfb,0xfc,0xfc,0xfd,0xfe,0xfe,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xfe,0xfe,0xfd,0xfc,0xfc,0xfb,0xfa,0xf9,0xf8,0xf7,0xf6,0xf5,0xf3,0xf2,0xf0,0xef,0xed,0xec,0xea,0xe8,0xe6,0xe4,0xe3,0xe1,0xde,0xdc,0xda,0xd8,0xd6,0xd3,0xd1,0xce,0xcc,0xc9,0xc7,0xc4,0xc1,0xbf,0xbc,0xb9,0xb6,0xb4,0xb1,0xae,0xab,0xa8,0xa5,0xa2,0x9f,0x9c,0x99,0x96,0x92,0x8f,0x8c,0x89,0x86,0x83,0x80,0x7d,0x79,0x76,0x73,0x70,0x6d,0x6a,0x67,0x64,0x61,0x5e,0x5b,0x58,0x55,0x52,0x4f,0x4c,0x49,0x46,0x43,0x41,0x3e,0x3b,0x39,0x36,0x33,0x31,0x2e,0x2c,0x2a,0x27,0x25,0x23,0x21,0x1f,0x1d,0x1b,0x19,0x17,0x15,0x14,0x12,0x10,0xf,0xd,0xc,0xb,0x9,0x8,0x7,0x6,0x5,0x4,0x3,0x3,0x2,0x1,0x1,0x0,0x0,0x0,0x0,0x0,0x0,0x0,0x0,0x0,0x0,0x0,0x1,0x1,0x2,0x3,0x3,0x4,0x5,0x6,0x7,0x8,0x9,0xa,0xc,0xd,0xe,0x10,0x12,0x13,0x15,0x17,0x18,0x1a,0x1c,0x1e,0x20,0x23,0x25,0x27,0x29,0x2c,0x2e,0x30,0x33,0x35,0x38,0x3b,0x3d,0x40,0x43,0x46,0x48,0x4b,0x4e,0x51,0x54,0x57,0x5a,0x5d,0x60,0x63,0x66,0x69,0x6c,0x6f,0x73,0x76,0x79,0x7c}
unsigned char keyscan()       //键盘扫描函数
{
unsigned char keyscan_num,temp;
P1=0xff; // P1口输入
    temp=P1; //从P1口读入键值，存入temp中
    if(~(temp&0xff))          //判是否有键按下，即键值不为0xff，则有键按下
{
if(key0==0) //产生正弦波的按键按下，
{
keyscan_num=1; //得到的键值为1，表示产生正弦波
     }
   else if(key1==0) //产生方波的按键按下，
     {
keyscan_num=2; //得到键值为2，表示产生方波
      }
else if(key2==0) //产生三角波的按键按下， P1.2=0
{
keyscan_num=3; //得到的键值为3，表示产生三角波
}
else if(key3==0) //产生梯形波的按键按下，P1.3=0
{
keyscan_num=4; //得到的键值为4，表示产生梯形波
}
else if(key4==0)
{
       keyscan_num=5;
}
else
   keyscan_num=0;
return(keyscan_num);
}
}
void init_DA0832()
{
rd=0;
wr=0;
}
void SIN()
{
unsigned int i;
do{
P2=SIN_code[i];
i=i+1;
}while(i<256);
}
void Square()
{
EA=1;
ET0=1;
TMOD=1;
TH0=0xff;
TL0=0x83;
TR0=1;
}
void Triangle()
{
P2=0x00;
do{
P2=P2+1;
}while(P2<0xff);
P2=0xff;
do{
P2=P2-1;
}while(P2>0x00);
P2=0x00;
}
void Sawtooth()
{
P2=0x00;
do{
P2=P2+1;
}while(P2<0xff);
}
void Trapezoidal()
{
unsigned char i;
P2=0x00;
do{
P2=P2+1;
}while(P2<0xff);
P2=0xff;
for(i=255;i>0;i--)
{
P2=0xff;
}
do{
P2=P2-1;
}while(P2>0x00);
P2=0x00;
}
void main() // 主函数
{
init_DA0832(); // DA0832的初始化函数
do
{
flag=keyscan(); //将键盘扫描函数得到的键值赋给flag
}while(!flag);
while(1)
{
   switch(flag)
         {
               case 1:
               do{
               flag=keyscan();
            SIN( );
      }while(flag==1);
      break;
  case 2:
   Square ();
   do{
      flag=keyscan();
   }while(flag==2);
   TR0=0;
   break;
   case 3:
   do{
         flag=keyscan();
      Triangle ();
}while(flag==3);
      break;
   case 4:
         do{
      flag=keyscan();
      Trapezoidal ();
}while(flag==4);
         break;
   case 5:
         do{
      flag=keyscan();
      Sawtooth ();
   }while(flag==5);
         break;
      default:
   flag=keyscan();
      break;
}
  }
}
void timer0(void) interrupt 1 //定时器T0的中断函数
{
  P2=~P2; //方波的输出电平求反
  TH0=0xff; //重装定时时间常数
  TL0=0x83;
  TR0=1; //启动定时器T0
}