Traffic light system on BKIT PIC

This is my project for HCMUT Computer Engineering course CO2021 - Logic Design Project: Simulating a 4-way intersection traffic light system on the BKIT PIC development board. More details are in the report file (written in Vietnamese).

Introduction

Traffic light system is a common application of an embedded system. In this project, I will simulating such a system using the BKIT PIC development board, which is based on the PIC18F4620 microcontroller and developed by BKIT Hardware Club.

Features

• The system that can work in 3 different mode: automatic countdown, manual, and standby.
• In automatic countdown mode, the lights will change its state when the countdown reaches zero.
• In manual mode, the lights' state can only be changed manually using the B button.
• Switch between these 2 modes using button A.
• In standby mode, only yellow lights will blink, switch to this mode using button #.
• Next 2 features are about the countdown timer. A special condition feature is simulated using 2 buttons C and D which stands for "entering special condition" and "leaving special condition", which will change the timer accordingly using 2 sets of predefined timers. In the real world, special conditions can be something like rush hour, or the state of the traffic.
• In addition to those 2 predefined timers, you can set it manually using the * and the number buttons.
• The last feature is force switching: the lights can go immediately from red to green and green to red using button 0. This is to simulate the case when there is a prioritized vehicle like an ambulance or a fire truck approaching the intersection. In the real application, the button can be replaced by something like a camera or a sensor.
• The output signals are simulated on a traffic light demonstration board, the design of that board on Altium Designer can be found in this repository.

Program structure

The program uses 4 modules: lcd, button, interrupt and timer. Its structure is shown in the diagram below:

Implementation

The system is designed using a state diagram based design with 14 states in total. The state diagram is shown below:

Demonstration

The video where I demonstrate the product in details can be accessed at this link: https://youtu.be/UaOuD4EGTHY

Contributors

DangLKM: https://github.com/LKMDang