Signal Generators

# Density Based Traffic Signal System using Microcontroller

In today’s fast-paced world, managing traffic has become a significant challenge due to the surge in vehicle numbers, resulting in substantial delays at traffic signal lights. To address this issue effectively, we are adopting a density-based traffic light system. This article provides a comprehensive explanation of how traffic control can be optimized based on traffic density.

Our approach involves the utilization of infrared sensors to gauge traffic density in this system. For each road, we install an IR sensor that continuously monitors traffic flow on that specific route. All of these sensors are linked to a central microcontroller. The role of the microcontroller is to detect and regulate the traffic system by leveraging data from these sensors.

### Outline

• Density Based Traffic Signal System Circuit Principle:
• Density Based Traffic Signal System Circuit Diagram:
• Circuit Components:
• Density Based Traffic Light Control System Circuit Design:
• Density based Traffic Signal System Circuit Simulation Video:
• How to Operate Density based Traffic Signal System Circuit?
• Density based Traffic Signal System Project Output Video:
• Limitations of this Circuit:

## Density Based Traffic Signal System Circuit Principle:

The microcontroller serves as the central control unit of this traffic management system. It interfaces with IR sensors via its PORT C (PC0, PC1, PC2, and PC3), while PORT B and PORT D are connected to the traffic lights. When traffic is detected on a road, the sensor output switches to logic 0; conversely, it switches to logic 1 in the absence of traffic. Our task is to develop an application that utilizes the IR sensor outputs to govern the traffic system.

Upon receiving a logic 0 signal from any of these sensors, we must authorize the green signal for that specific route while displaying a red signal for all other routes. Continuously, we need to monitor the IR sensors to assess the traffic conditions.

## Density Based Traffic Signal System Circuit Diagram:

### Circuit Components:

• ATmega8 controller
• PCB board
• IR sensors -4
• LED’s-12(4-red,4-green,4-yellow)
• Serial cable
• Connecting wires

## Density Based Traffic Light Control System Circuit Design:

This circuit comprises four infrared sensors, an ATmega8 microcontroller, and four traffic lights.

The IR transmitter bears a resemblance to an LED and consistently emits IR beams. Its operational voltage falls within the 2 to 3 volts range. These infrared (IR) rays are imperceptible to the naked eye but can be visualized using a camera.

On the other hand, the IR receiver is designed to capture the IR rays emitted by the IR transmitter. Ordinarily, an IR receiver exhibits a high resistance in the mega ohm range, which substantially drops when it receives IR photons. The IR receiver’s operational voltage also spans from 2 to 3 volts.

Proper alignment of these IR pairs is crucial to ensure that the IR receiver can receive IR rays even in the presence of an obstacle. When the power is activated, the transmitted IR rays impinge upon an object and subsequently bounce back to be detected by the IR receiver.

Instead of traditional traffic signals (RED, GREEN, YELLOW), LEDs can be employed. In a standard traffic system, LEDs must remain illuminated continuously. If traffic density is high on a specific route, the green LED for that route illuminates, while the red LEDs for other routes remain lit.

In a conventional traffic system, each route is allocated a one-minute time delay.

The above figure shows the IR sensor circuit. Here 330 ohm resistor is used to drop the voltage otherwise IR transmitter may get damaged. To vary the obstacle sensing distance, we have used a potentiometer. We have taken the ouput from transistor collector. This sensor gives the digital output.

## How to Operate Density based Traffic Signal System Circuit?

• Connect 12V battery or adaptor to the development board.
• Switch on the supply.
• Burn the program to the ATmega8 microcontroller by keeping the programming switch sw2 in program mode.
• Connect four IR sensors to PORT C.
• Connect LEDs to PORT B and PORT D.
• Arrange all this LED’s same as like traffic lights.
• Arrange one IR sensor for each road.
• Now you can see the normal traffic system based on time basis.
• Now if you place any obstacle in front of any IR sensor, then the system allows the traffic of that particular path by glowing GREEN light.
• Finally, turn off the board power supply.

## Limitations of this Circuit:

• IR sensors sometimes may absorb normal light also. As a result, traffic system works in improper way.
• IR sensors work only for fewer distances.
• We have to arrange IR sensors in accurate manner otherwise they may not detect the traffic density.

Check Also
Close

Close
Close