4 Way Traffic Light Controller using Microcontroller

BLOCK DIAGRAM:

PARTS Needed:

1.MICROCONTROLLER

2.RESISTOR

3.LED

4.BATTERY

1.MICROCONTROLLER:

AT89S52 IS A CONTROLLER WHICH IS USED TO CONTROLL THE LED

2.RESISTOR:

330OHM RESISTOR IS USED TO RESIST THE SUPPLY WHICH WE HAVE GIVEN

3.LED:

led is to visit the output

4.BATTERY:

9v, RECHARGABLE BATTERY

HOW  IT  WORKS:

Microcontroller turns the port on and off with which we connect the LEDs.
Key thing is how the expected time delay is achieved.

CIRCUITDIAGRAM:

CODE:

 org 0x00
 loop:
   mov p2,#0f1h
   clr p1.0
   call delay
   setb p1.0
   call delay
   mov p2,#0e1h
   call delay

   mov p2,#0f2h
   clr p1.1
   call delay
   setb p1.1
   call delay
   mov p2,#0d2h
   call delay
   mov p2,#0f4h
   clr p1.2
   call delay
   setb p1.2
   call delay
   mov p2,#0b4h
   call delay
 mov p2,#0f8h
   clr p1.3
   call delay
   setb p1.3
   call delay
   mov p2,#78h
   call delay

   jmp loop
 delay:
   mov r1,#2
 l1:
   mov r2,#212
 l2:
   mov r3,#255
 l3:
   mov r4,#255
 l4:
   djnz r4,l4
   djnz r3,l3
   djnz r2,l2
   djnz r1,l1
   ret
   end

HEX CODE:

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:1000100012004F75A0F2C29112004FD29112004F00
:1000200075A0D212004F75A0F4C29212004FD29266
:1000300012004F75A0B412004F75A0F8C2931200C1
:010040004F70
:10004100D29312004F75A07812004F02000079027E
:0F0051007AD47BFF7CFFDCFEDBFADAF6D9F222F1
:00000001FF