Traffic light controller using microprocessor

Traffic light dominance using microprocessorTraffic Light Controller Using 8085 MicroprocessorintentionThe main aim of this project is to design a Traffic light controller using 8085 microprocessor, interfacing with peripheral device 8085, and program implementing the process.IntroductionThe 8085 Microprocessor is a touristy Microprocessor used in Industries for various applications. Such as duty light control, temperature control, stepper motor control, etc. In this project, the work lights be interfaced to Microprocessor system with buffer and styles of programmable peripheral Interface 8255. So the traffic lights can be automatically switched ON/OFF in desired sequence. The Interface get along with has been knowing to work with parallel port of Microprocessor system.The hardwargon of the system consists of two parts. The first part is Microprocessor based system with 8085. Microprocessor as CPU and the peripheral devices like EPROM, RAM, Keyboard reveal Controller 8279, Programmable as Peripheral Interface 8255, 26 pin parallel port connector, 21 keys Hexa key pad and six number of seven plane section LEDs.The second part is the traffic light controller interface board, which consist of 36 LEDs in which 20 LEDs be used for vehicle traffic and they are connected to 20 port lines of 8255 through Buffer. Remaining LEDs are used for pedestrian traffic. The traffic light interface board is connected to Main board using 26 core flat cables to 26-pin Port connector. The LEDs can be switched ON/OFF in the specified sequence by the Microprocessor.The normal drop dead of traffic lights requires sophisticated control and coordination to ensure that traffic moves as smoothly and safely as possible and that pedestrians are protected when they cross the roads. A vicissitude of different control systems are used to accomplish this, ranging from simple clockwork mechanisms to sophisticated computerized control and coordination systems that self-adjust to mini mize hamper to people using the road.Traffic Controller SystemsA traffic signal is typically controlled by a controller inside a cabinet mounted on a concrete pad. Although some electro-mechanical controllers are still in use (New York City still has 4,800), modern traffic controllers are solid state. The cabinet typically contains a power panel, to distribute galvanising power in the cabinet a detector interface panel, to connect to loop detectors and other detectors detector amplifiers the controller itself a conflict monitor building block flash transfer relays a police panel, to allow the police to disable the signal and other components.Fixed Time ControlThe simplest control system uses a durationr (fixed-time) each phase of the signal lasts for a specific duration before the next phase occurs this pattern repeats itself regardless of traffic. Many older traffic light installations still use these, and timer-based signals are effective in one way grids where it is often pos sible to coordinate the traffic lights to the posted speed limit. They are however disadvantageous when the signal timing of an intersection would profit from being adapted to the dominant flows changing over the time of the day.Dynamic ControlDynamic, or actuated, signals are programmed to adjust their timing and phasing to meet changing traffic conditions. The system adjusts signal phasing and timing to minimize the delay of people going through the intersection. It is overly commonplace to alter the control strategy of a traffic light based on the time of day and day of the week, or for other particular(prenominal) circumstances such as a major event causing unusual demand at an intersection.The controller uses input from detectors, which are sensors that inform the controller processor whether vehicles or other road users are present, to adjust signal timing and phasing within the limits set by the controllersprogramming. It can deem more time to an intersection approach that is experiencing heavy traffic, or shorten or even skip a phase that has little or no traffic hold for a green light. Detectors can be grouped into three classes in-pavement detectors, non-intrusive detectors, and detection for non-motorized road users.Working ProgramDesign of a microprocessor system to control traffic lights. The traffic light arrangement is as shown in Fig. The traffic should be controlled in the following manner.1) Allow traffic from W to E and E to W alteration for 20 seconds. 2) Give transition period of 5 seconds (Yellow bulbs ON) 3) Allow traffic from N to 5 and 5 to N for 20 seconds 4) Give transition period of 5 seconds (Yellow bulbs ON) 5) Repeat the process.Source ProgramMVI A, 80H Initialize 8255, port A and port B forbidden 83H (CR) in output mode seize on MVI A, 09HOUT 80H (PA) Send data on PA to glow R1 and R2MVI A, 24HOUT 81H (PB) Send data on PB to glow G3 and G4MVI C, 28H Load multiplier numeration (40) for delayCALL DELAY Call delay subroutine MVI A, 12HOUT (81H) PA Send data on Port A to glow Y1 and Y2OUT (81H) PB Send data on port B to glow Y3 and Y4MVI C, 0AH Load multiplier compute (10) for delayCALL DELAY Call delay subroutineMVI A, 24HOUT (80H) PA Send data on port A to glow G1 and G2MVI A, 09HOUT (81H) PB Send data on port B to glow R3 and R4MVI C, 28H Load multiplier count (40) for delayCALL DELAY Call delay subroutineMVI A, 12HOUT PA Send data on port A to glow Y1 and Y2OUT PB Send data on port B to glow Y3 and Y4MVI C, 0AH Load multiplier count (10) for delayCALL DELAY Call delay subroutineJMP STARTDelay SubroutineDELAY LXI D, Count Load count to give 0.5 sec delayBACK DCX D Decrement counterMOV A, DORA E Check whether count is 0JNZ BACK If not zero, repeatDCR C Check if multiplier zero, otherwise repeatJNZ DELAYRET Return to main programReferencesv www.rbainnovations.com//A%208085/H%20Traffic%20light%20controller-n.docv www.freshpatents.com/-dt20090702ptan20090167561.phpv http//www.8085projects.info/ scalawag/ free-programs-for-8085-microprocessor.aspxv http//www.8085projects.info/post/Traffic-Light-Control.aspxv U.S.Shah, Microprocessor and its applications, Tech- Max Pulications, Pune.