The 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 popular Microprocessor used in Industries for various applications. Such as traffic light control, temperature control, stepper motor control, etc. In this project, the traffic lights are interfaced to Microprocessor system through buffer and ports of programmable peripheral Interface 8255. So the traffic lights can be automatically switched ON/OFF in desired sequence. The Interface board has been designed to work with parallel port of Microprocessor system.The hardware 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 & Display Controller 8279, Programmable as Peripheral Interface 8255, 26 pin parallel port connector, 21 keys Hexa key pad and six number of seven segment LED's.The second part is the traffic light controller interface board, which consist of 36 LED's in which 20 LED's are used for vehicle traffic and they are connected to 20 port lines of 8255 through Buffer. Remaining LED's 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 LED's can be switched ON/OFF in the specified sequence by the Microprocessor. Get Help With Your EssayIf you need assistance with writing your essay, our professional essay writing service is here to help!
Traffic Light Controller Using 8085 Microprocessor Pdf Free 11
The normal function 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 variety 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 minimize delay 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 electrical power in the cabinet; a detector interface panel, to connect to loop detectors and other detectors; detector amplifiers; the controller itself; a conflict monitor unit; 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 timer (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 possible 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 also commonplace to alter the control strategy of a traffic light based on the time of day and day of the week, or for other special 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 give more time to an intersection approach that is experiencing heavy traffic, or shorten or even skip a phase that has little or no traffic waiting 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 should be controlled in the following manner.1) Allow traffic from W to E and E to W transition 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 Program:MVI A, 80H: Initialize 8255, port A and port BOUT 83H (CR): in output modeSTART: 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 count (40ıο) for delayCALL DELAY: Call delay subroutineMVI 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 count (10ıο) 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 (40ıο) 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 (10ıο) for delayCALL DELAY: Call delay subroutineJMP STARTDelay Subroutine:DELAY: 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 programReferenceswww.rbainnovations.com/.../A%208085/H%20Traffic%20light%20controller-n.docwww.freshpatents.com/-dt20090702ptan20090167561.php -programs-for-8085-microprocessor.aspx -Light-Control.aspxU.S.Shah, Microprocessor and its applications, Tech- Max Pulications, Pune. Share this:FacebookFacebook logoTwitterTwitter logoRedditReddit logoLinkedInLinkedIn logoWhatsAppWhatsApp logo Cite This WorkTo export a reference to this article please select a referencing stye below:
Abstract:Vehicular traffic is endlessly increasing everywhere in the world and can cause terrible traffic congestion at intersections. Most of the traffic lights today feature a fixed green light sequence, therefore the green light sequence is determined without taking the presence of the emergency vehicles into account. Therefore, emergency vehicles such as ambulances, police cars, fire engines, etc. stuck in a traffic jam and delayed in reaching their destination can lead to loss of property and valuable lives. This paper presents an approach to schedule emergency vehicles in traffic. The approach combines the measurement of the distance between the emergency vehicle and an intersection using visual sensing methods, vehicle counting and time sensitive alert transmission within the sensor network. The distance between the emergency vehicle and the intersection is calculated for comparison using Euclidean distance, Manhattan distance and Canberra distance techniques. The experimental results have shown that the Euclidean distance outperforms other distance measurement techniques. Along with visual sensing techniques to collect emergency vehicle information, it is very important to have a Medium Access Control (MAC) protocol to deliver the emergency vehicle information to the Traffic Management Center (TMC) with less delay. Then only the emergency vehicle is quickly served and can reach the destination in time. In this paper, we have also investigated the MAC layer in WSNs to prioritize the emergency vehicle data and to reduce the transmission delay for emergency messages. We have modified the medium access procedure used in standard IEEE 802.11p with PE-MAC protocol, which is a new back off selection and contention window adjustment scheme to achieve low broadcast delay for emergency messages. A VANET model for the UTMS is developed and simulated in NS-2. The performance of the standard IEEE 802.11p and the proposed PE-MAC is analysed in detail. The NS-2 simulation results have shown that the PE-MAC outperforms the IEEE 802.11p in terms of average end-to-end delay, throughput and energy consumption. The performance evaluation results have proven that the proposed PE-MAC prioritizes the emergency vehicle data and delivers the emergency messages to the TMC with less delay compared to the IEEE 802.11p. The transmission delay of the proposed PE-MAC is also compared with the standard IEEE 802.15.4, and Enhanced Back-off Selection scheme for IEEE 802.15.4 protocol [EBSS, an existing protocol to ensure fast transmission of the detected events on the road towards the TMC] and the comparative results have proven the effectiveness of the PE-MAC over them. Furthermore, this research work will provide an insight into the design of an intelligent urban traffic management system for the effective management of emergency vehicles and will help to save lives and property.Keywords: VANETs; audio visual sensing; emergency vehicle; traffic lights; traffic monitoring; priority; distance measurement techniques 2ff7e9595c
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