参考《51单片机C语言创新教程》温子祺等著。
源码转自：《51单片机C语言创新教程》。
/*实验名称:交通灯实验
*描 述:交通灯实验要求红灯亮15秒，绿灯亮10秒，黄灯亮5秒，
当红灯切换为绿灯或者绿灯切换为红灯，
要实现灯闪烁。红灯、绿灯、黄灯的点亮持续时间可以通过串口来修改，
并在下一个循环中更新数值。
*作 者:温子祺
*修改日期:2010/5/4
*说 明:代码注释与讲解详见《51单片机C语言创新教程》温子祺等著，北京航空航天大学出版社
*/
#include "stc.h"
typedef unsigned char UINT8;
typedef unsigned int UINT16;
typedef unsigned long UINT32;
typedef char INT8;
typedef int INT16;
typedef long INT32;
#define TIMER0_INITIAL_VALUE 5000
#define HIGH 1
#define LOW 0
#define ON 1
#define OFF 0
#define SEG_PORT P0
#define LS164_DATA(x) {if((x))P0_4=1;else P0_4=0;}
#define LS164_CLK(x) {if((x))P0_5=1;else P0_5=0;}
#define NORTH_R_LIGHT(x) {if((x))P2_0=0;else P2_0=1;}
#define NORTH_Y_LIGHT(x) {if((x))P2_1=0;else P2_1=1;}
#define NORTH_G_LIGHT(x) {if((x))P2_2=0;else P2_2=1;}
#define SOUTH_R_LIGHT(x) {if((x))P2_3=0;else P2_3=1;}
#define SOUTH_Y_LIGHT(x) {if((x))P2_4=0;else P2_4=1;}
#define SOUTH_G_LIGHT(x) {if((x))P2_5=0;else P2_5=1;}
#define TRAFFIC_STATUS_1 0
#define TRAFFIC_STATUS_2 1
#define TRAFFIC_STATUS_3 2
#define UART_MARKER 0xEE
UINT8 Timer0IRQEvent=0;
UINT8 Time1SecEvent=0;
UINT8 Time500MsEvent=0;
UINT8 TimeCount=0;
UINT8 SegCurPosition=0;
UINT8 LightOrgCount[4]={15,5,15,5};
UINT8 LightCurCount[4]={15,5,15,5};
UINT8 TrafficLightStatus=0;
code UINT8 SegCode[10] ={0xC0,0xF9,0xA4,0xB0,0x99,0x92,0x82,0xF8,0x80,0x90};
UINT8 SegBuf[4] ={0};
code UINT8 SegPosition[4]={0x07,0x0b,0x0d,0x0e};
typedef struct _LIGHT_VAL
{
UINT8 Head;
UINT8 val[4];
}LIGHT_VAL;
typedef union _LIGHT_VAL_EX
{
LIGHT_VAL lv;
UINT8 p[5];
}LIGHT_VAL_EX;
void LS164Send(UINT8 byte)
{
UINT8 j;
for(j=0;j<=7;j++)
{
if(byte&(1<<(7-j)))
{
LS164_DATA(HIGH);
}
else
{
LS164_DATA(LOW);
}
LS164_CLK(LOW);
LS164_CLK(HIGH);
}
}
void RefreshDisplayBuf(UINT8 s1) //刷新显示缓存
{
SegBuf[0] = s1%10;
SegBuf[1] = s1/10;
SegBuf[2] = s1%10;
SegBuf[3] = s1/10;
}
void SegDisplay(void)
{
UINT8 t;
t = SegCode[SegBuf[SegCurPosition]];
SEG_PORT |= 0x0f;
LS164Send(t);
SEG_PORT = (SEG_PORT|0x0f) & SegPosition[SegCurPosition];
if(++SegCurPosition>=4)
{
SegCurPosition=0;
}
}
void TimerInit(void)
{
TH1 = 0;
TL1 = 0;
TH0 = (65536-TIMER0_INITIAL_VALUE)/256;
TL0 = (65536-TIMER0_INITIAL_VALUE)%256; //定时1MS
TMOD = 0x51; /*01010001 T1计数,T0定时*/
}
void Timer0Start(void)
{
TR0 = 1; //启动计时器1
ET0 = 1;
}
void Timer0Stop(void)
{
TR0 = 0; //启动计时器1
ET0 = 0;
}
void PortInit(void)
{
P0=P1=P2=P3=0xFF;
}
void UartInit(void)
{
SCON=0x40;
T2CON=0x34;
RCAP2L=0xD9;
RCAP2H=0xFF;
REN=1;
ES=1;
}
void UartSendByte(UINT8 byte)
{
SBUF=byte;
while(TI==0);
TI=0;
}
void UartPrintfString(INT8 *str)
{
while(str && *str)
{
UartSendByte(*str++);
}
}
void main(void)
{
UINT8 i=0;
PortInit();
TimerInit();
Timer0Start();
UartInit();
RefreshDisplayBuf(LightCurCount[0]);
EA=1;
NORTH_R_LIGHT(ON);
SOUTH_G_LIGHT(ON);
while(1)
{
if(Timer0IRQEvent)
{
Timer0IRQEvent=0;
TimeCount++;
if(TimeCount>=200)
{
TimeCount=0;
if(LightCurCount[0])
{
TrafficLightStatus=0;
}
else if(LightCurCount[1])
{
TrafficLightStatus=1;
}
else if(LightCurCount[2])
{
TrafficLightStatus=2;
}
else if(LightCurCount[3])
{
TrafficLightStatus=3;
}
else
{
for(i=0;i<4;i++)
{
LightCurCount[i]=LightOrgCount[i];
}
TrafficLightStatus=0;
}
switch(TrafficLightStatus)
{
case 0:
{
NORTH_R_LIGHT(ON);
SOUTH_R_LIGHT(OFF);
NORTH_G_LIGHT(OFF);
SOUTH_G_LIGHT(ON);
NORTH_Y_LIGHT(OFF);
SOUTH_Y_LIGHT(OFF);
}
break;
case 1:
{
if(LightCurCount[1]%2)
{
NORTH_R_LIGHT(ON);
SOUTH_G_LIGHT(ON);
}
else
{
NORTH_R_LIGHT(OFF);
SOUTH_G_LIGHT(OFF);
}
NORTH_Y_LIGHT(ON);
SOUTH_Y_LIGHT(ON);
}
break;
case 2:
{
NORTH_R_LIGHT(OFF);
SOUTH_R_LIGHT(ON);
NORTH_G_LIGHT(ON);
SOUTH_G_LIGHT(OFF);
NORTH_Y_LIGHT(OFF);
SOUTH_Y_LIGHT(OFF);
}
break;
case 3:
{
if(LightCurCount[3]%2)
{
NORTH_G_LIGHT(ON);
SOUTH_R_LIGHT(ON);
}
else
{
NORTH_G_LIGHT(OFF);
SOUTH_R_LIGHT(OFF);
}
NORTH_Y_LIGHT(ON);
SOUTH_Y_LIGHT(ON);
}
break;
default:break;
}
RefreshDisplayBuf(LightCurCount[TrafficLightStatus]);
LightCurCount[TrafficLightStatus]--;
}
SegDisplay();
}
}
}
void UartIRQ(void)interrupt 4
{
static UINT8 cnt=0;
static LIGHT_VAL_EX LightValEx;
if(RI)
{
RI=0;
LightValEx.p[cnt++]=SBUF;
if(LightValEx.lv.Head == UART_MARKER)
{
if(cnt>=5)
{
for(cnt=1;cnt<5;cnt++)
{
LightOrgCount[cnt-1]=LightValEx.lv.val[cnt];
LightCurCount[cnt-1]=LightValEx.lv.val[cnt];
}
cnt=0;
UartPrintfString("设置交通灯完成\r\n");
}
}
else
{
cnt=0;
}
}
}
void Timer0IRQ(void) interrupt 1
{
ET0 = 0;
TH0 = (65536-TIMER0_INITIAL_VALUE)/256;
TL0 = (65536-TIMER0_INITIAL_VALUE)%256; //定时1MS
Timer0IRQEvent=1;
ET0 = 1;
}
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坐等拿分！
where 数码显示 is
