Proteus7.7+Keil2 simulation 80C51 control intersection signal light (with left turn signal light)

In order to design a traffic light with a left turn signal at an intersection, one must first thoroughly understand the control logic of the circular traffic light.

In the design process of this example, I designed the signal control logic of this intersection: north-south straight-through release -> east-west straight-through release -> north-south left turn release -> east-west left turn release. If the display problem of the digital tube is not considered, it is only necessary to slightly modify the control program of the circular signal light. However, in actual applications, most intersections are equipped with digital display digital tubes to display the countdown seconds of the red, yellow and green lights in the straight direction to improve traffic efficiency - so it is very necessary to add the countdown display function to the design.

I drew the complete signal control logic as the following diagram.

In actual programming, since I did not fully understand the control logic at the beginning, the control program I wrote was completed by patching up the circular signal control system, which was somewhat accidental. When analyzing this example, I suggest that you first thoroughly understand the control logic, and then ignore the countdown display. After confirming that the design is correct, add the countdown display function. In addition, I have sent all the files of this example design to my resource area, and you are welcome to download and use it.

#include

#include

void delay()//delay 0.5s

{

short i, j;

for(i=0;i<124;i++)

for(j=0;j<500;j++)

;

}

void delay_night()//delay 1s

{

short i, j;

for(i=0;i<248;i++)

for(j=0;j<500;j++)

;

}

void main()

{

short int t=0, t1=0, t2=0; //t1 is responsible for timing the straight signal, t2 is responsible for timing the left turn signal, and t is responsible for the display of the digital tube

   P0=0;

P1=0;

   P2=0;

P3=0;

while(1)

{

//Straight module, in this module, the left turn signals in the north-south and east-west directions are all red

P0=0x12;

//Green light cycle in north-south direction

P2=0x14; //Green light on in north-south direction + red light on in east-west direction

t1=35;

while(t1>=0)

{

P1=t1/2/10*pow(2,4)+t1/2%10; //North-South direction digital tube setting

P3=(t1/2+3)/10*pow(2,4)+(t1/2+3)%10; //Set the digital tube in the east-west direction

if(t1<=5) //The green light in the north-south direction lasts for 3 seconds

{

if(t1%2!=0)

{

P2=0x10; //Green light in north-south direction is off + red light in east-west direction is on

}

else

{

P2=0x14; //Green light on in north-south direction + red light on in east-west direction

}

}

delay();

t1--;

}

// Yellow light cycle in north-south direction

P2=0x12; // Yellow light on in north-south direction + red light on in east-west direction

t1=5;

while(t1>=0)

{

P1=t1/2/10*pow(2,4)+t1/2%10; //North-South direction digital tube setting

P3=t1/2/10*pow(2,4)+t1/2%10; //Set the digital tube in the east-west direction

delay();

t1--;

}

//Red light cycle in north-south direction (need to add the time for turning left in both directions)

P2=0x41; //Red light on in the north-south direction + green light on in the east-west direction

t1=77;

t=t1+88; //The north-south digital tube displays 88=41+5+39+3

while(t1>=0)

{

if(t1/2>2)

{

P1=t/2/10*pow(2,4)+t/2%10; //North-South direction digital tube setting

P3=(t1/2-3)/10*pow(2,4)+(t1/2-3)%10; //Set the digital tube in the east-west direction

if(t1/2<=5) //The green light in the east-west direction lasts for 3 seconds

{

if(t1%2!=0)

{

P2=0x01; //Red light on in the north-south direction + green light off in the east-west direction

}

else

{

P2=0x41; //Red light on in the north-south direction + green light on in the east-west direction

}

}

}

else //Red light on in north-south direction + yellow light on in east-west direction

{

P2=0x21; //Red light on in the north-south direction + yellow light on in the east-west direction

P1=t/2/10*pow(2,4)+t/2%10; //North-South direction digital tube setting

P3=t1/2/10*pow(2,4)+t1/2%10; //Set the digital tube in the east-west direction

}

delay();

t1--;

t--;

}

//Left turn module, during which the lights for north-south and east-west directions are all red

P2=0x11; //Change the light for driving in the east-west direction to red P24=1, and change the light for driving in the north-south direction to red P20=1

//Green light cycle in north-south direction

P0=0x18; //Green light on in north-south direction + red light on in east-west direction P03=1, P04=1

t2=41;

while(t2>=0)

{

if(t2<=5) //The green light in the north-south direction lasts for 3 seconds

{

if(t2%2!=0)

{

P0=0x10; //Green light in north-south direction is off + red light in east-west direction is on

}

else

{

P0=0x18; //Green light on in north-south direction + red light on in east-west direction

}

}

P1=t/2/10*pow(2,4)+t/2%10; //North-South direction digital tube setting

P3=(t+46)/2/10*pow(2,4)+(t+46)/2%10; //Set the digital tube in the east-west direction

delay();

t2--;

t--;

}

// Yellow light cycle in north-south direction

P0=0x14; // Yellow light on in north-south direction + red light on in east-west direction P02=1, P04=1

t2=5;

while(t2>=0)

{

P1=t/2/10*pow(2,4)+t/2%10; //North-South direction digital tube setting

P3=(t+46)/2/10*pow(2,4)+(t+46)/2%10;;//Set the digital tube in the east-west direction 46=41+5

delay();

t2--;

t--;

}

//Red light cycle in north-south direction

P0=0x42; //Red light on in north-south direction + green light on in east-west direction P01=1, P06=1

t2=39;

while(t2>=0)

{

if(t2/2>2)

{

if(t2/2<=5) //The green light in the east-west direction lasts for 3 seconds

{

if(t2%2!=0)

{

P0=0x02; //Red light on in the north-south direction + green light off in the east-west direction

}

else

{

P0=0x42; //Red light on in the north-south direction + green light on in the east-west direction

}

}

}

else //Red light in north-south direction is on + yellow light in east-west direction is on P01=1, P05=1

{

P0=0x22; //Red light on in north-south direction + yellow light on in east-west direction

}

P1=t/2/10*pow(2,4)+t/2%10; //North-South direction digital tube setting

P3=(t+46)/2/10*pow(2,4)+(t+46)/2%10; //Set the digital tube in the east-west direction

delay();

t2--;

t--;

}

}

}