Traffic lights were first invented in the year 1868 in the House of Commons of London, where the traffic lights were placed at the intersections of George and Bridge Street. Later the traffic lights were developed in the year 1914 by an American traffic sign company, which set the green and red lights at the corners of 105th Street and Euclid Avenue in Cleveland, Ohio. During this period, traffic lights were controlled by timing or by manual change.
Traffic lights are also called traffic lights, traffic lights, traffic lights, stop-and-go lights that are signposts placed at highway crossings, daily pedestrian crossings, and other places to control competitive traffic flows. Semaphores have been set up around the world in many cities. The traffic light control assigns a correct route to road users using normal color lights (red - amber / yellow - green). The traffic light control system uses a global color code (a specific color to allow color recognition for those who are blind).
The main purpose of this traffic light controller is to provide sophisticated control and coordination to confirm that traffic moves with the greatest possible peace of mind and safety. This project makes use of LED lights for display purposes and a microcontroller is used for automatic switching of the signal at the specified interval of time interval. The LED lights automatically turn on and off, causing the corresponding microcontroller port pin to "HIGH".
Operation of the traffic light controller
In the above circuit diagram of the semaphore controller, a seven-segment display is used as a counter display, and three LEDs are used for semaphore control. An 8051 microcontroller is the brain of this whole project and is used to initiate the traffic signal at road intersections. This circuit diagram makes use of a crystal oscillator to generate frequency clock pulses. The LEDs are connected to the zero port of the microcontroller and are powered by a 5v power supply. The seven-segment display is connected to the 8051 microcontroller port 2 pins with a common anode configuration.
The LEDs are automatically switched on and off making the corresponding microcontroller port pins high, based on the 8051 microcontroller and programming using the KEIL software. In a certain period of time, only the green light stays on and the other lights remain off, and after some time, the control of the light from the green to red shift light takes place making the next change to turn on yellow LED . This process continues as a cycle and the time to change the LEDs can be visualized using a seven-segment LED display in this project.
This semaphore control system can be further improved in such a way to control traffic signals automatically based on the density of traffic on roads with the help of IR sensor modules with automatic deviation if there are no vehicles on both sides of the road Which leads to energy consumption.