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Traffic Light Control Application System on STM32F103RB2

This repository hosts a traffic light control application designed for an intersection with adjustable timing in both automatic and manual modes. The system utilizes mechanical buttons with software debouncing to manage the three phases—red, amber, and green. Developed using the STM32F103RB2, it implements a Finite State Machine (FSM) to manage various modes. The system has been validated on real hardware, specifically on an STM32F103RB2 board, and features an LCD 16x2 display for real-time information along with debounced mechanical buttons for mode selection and timing adjustments. This project is an enhanced version of the Traffic-light-STM32F103C6 project.

Table of Contents

1. Project Overview
2. Features
3. Hardware Requirements
4. Languages and Tools
5. Project Structure
6. Mode Descriptions
7. How to Build and Run
8. Implementing on Hardware

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1. Project Overview

This project simulates a traffic light system at a crossroads with the following characteristics:

• 12 LEDs (4 red, 4 amber, 4 green) corresponding to two directions of traffic.
• 4 seven-segment displays (two per road) to show countdown time and mode number.
• 3 buttons:
  1. Mode Selection: Cycles through 4 modes
  2. Time Increase: Increments the time duration in modification modes
  3. Time Set: Confirms and stores the chosen time.

An FSM (Finite State Machine) is used to manage the modes, transitions, and LED blinking behavior. The design also includes software-based button debouncing and a flexible timer configuration to ensure stable performance.

Main Goals

1. Normal Traffic Light Operation (Mode 1).
2. On-the-Fly Modification of Red, Amber and Green Durations (Modes 2, 3, 4).
3. Stable Timer and Debouncing: Changing timer interrupt intervals without affecting the main application logic.

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2. Features

• Operating Modes (4 total):

  1. Normal Mode: Standard traffic light sequence
  2. Modify Red Duration
  3. Modify Amber Duration
  4. Modify Green Duration

• Real-Time Display on LCD 16x2 using I2C protocol showing:

  • Current countdown time for each color.
  • Current mode indication during editing.

• Blinking LEDs in modification modes (2 Hz) to indicate the active editing state and also which color is being edited.

• Button Debouncing using software debouncing method for all 3 push buttons to ensure stable input readings.

• Adjustable Timer Interrupt (10 ms default) that can be configured to 1 ms or 100 ms without impacting the overall system behavior.

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3. Hardware Requirements

• STM32F103RB2 board
• 12 LEDs: 4 red, 4 amber, 4 green
• 16x2 I2C LCD Displays (common anode or cathode, depending on your design)
• 3 Push Buttons for:
  1. Mode Selection: to select modes
  2. Time Increase: to modify the time for each color LED on the fly
  3. Time Set: to set the chosen value

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4. Languages and Tools

Languages

Tools

• STM32CubeIDE: STM32CubeIDE Download

• STM32CubeProgrammer: STM32CubeProgrammer Download

• Proteus Simulation Software: Proteus Information

Ensure your development environment is configured for STM32 microcontrollers.

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5. Project Structure

.
├── stm32_rb/                          # Main source directory for the STM32RB project
│   ├── .settings/                     # Project settings and preferences
│   ├── Core/                          # Core source code and headers
│   │   ├── Inc/                       # Header files
│   │   │   ├── button.h              
│   │   │   ├── fsm_automatic.h       
│   │   │   ├── fsm_manual.h          
│   │   │   ├── global.h              
│   │   │   ├── i2c-lcd.h             
│   │   │   ├── led_7_seg.h             # This file is not used
│   │   │   ├── led_states.h          
│   │   │   ├── main.h          
│   │   │   ├── software_timer.h      
│   │   │   └── ...             
│   │   └── Src/                      # Source code files
│   │       ├── button.c              # Button reading and debouncing logic
│   │       ├── fsm_automatic.c       # FSM implementation for normal mode
│   │       ├── fsm_manual.c          # FSM implementation for the whole system (Mode 1-4)
│   │       ├── global.c              # Global variables and timing settings
│   │       ├── i2c-lcd.c             # LCD display implementation
│   │       ├── led_7_seg.c           # This file is not used
│   │       ├── led_states.c          # Implement all the states of 12 LEDs
│   │       ├── main.c                # Main loop integrating FSM 
│   │       ├── software_timer.c      # Timer configuration and interrupt 
│   │       └──...                 
│       └── Startup
│   ├── Debug/                         # Debug build output (hex file in here)
│   ├── Drivers/                       # STM32 drivers and libraries
│   ├── STM32F103RBTX_FLASH.ld         # Linker script for STM32F103RBT6
│   ├── STM32_RB_Traffic_light_sys.ioc # STM32CubeMX configuration file
│   ├── .cproject                      # Eclipse project configuration
│   ├── .mxproject                     # STM32CubeMX project metadata
│   ├── .project                       # Eclipse project metadata
│   
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├── .project
├── README.md                            # You're reading this file
├── Traffic-light-system-STM32F103RB2-Demo.gif

Notable Files

• main.c: Initializes hardware, put fsm logic in main loop.
• fsm.c / fsm.h: Contains the FSM logic for mode control.
• button.c / button.h: Button reading (press, hold) and software debouncing.
• i2c-lcd.c / i2c-lcd.h: I2C protocol functions to display mode and time on the 16x2 LCD.
• timer.c / timer.h: Timer setup for periodic interrupts (default 10 ms).

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6. Mode Descriptions

1. Mode 1 - Normal Mode

   • Traffic lights operate normally with fixed durations for Red, Amber, and Green.
   • 7-segment displays show the remaining time for the current LED color in each direction.

2. Mode 2 - Modify Red LEDs

   • Red LEDs blink at 2 Hz to indicate we are editing their time duration.
   • Use the second button to increase the time (1–99 seconds).
   • Press the third button to confirm and save the new time.
   • The 7-segment displays show the mode number and the current time for Red.

3. Mode 3 - Modify Amber LEDs

   • Similar behavior to Mode 2, but for the Amber LED duration.

4. Mode 4 - Modify Green LEDs

   • Similar behavior to Mode 2, but for the Green LED duration.

Press the first button at any time to cycle through modes (1 → 2 → 3 → 4 → 1 → ...). Initially, the system runs with 5 seconds for Red, 3 seconds for Amber, and 2 seconds for Green. After that, when it returns to mode 1, the system runs with the new setting time or the same time if the user does not modify anything.

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7. How to Build and Run

1. Clone the Repository

   git clone https://github.com/NgqvngVinh/Traffic-light-system-STM32F103RB2.git
   cd Traffic-light-system-STM32F103RB2

2. Open Project in your preferred STM32 IDE (recommend: STM32CubeIDE).

3. Check Pin Assignments: Ensure the pin assignments in the .ioc file (STM32_RB_Traffic_light_sys.ioc) match your actual hardware connections (LEDs, buttons, LCD).

4. Build the Project

   • Compile the code (Ctrl + B) and generate the .hex file.
   • If the .hex file is not generated, go to C/C++ Build > Settings > MCU Post Build Outputs and enable the Intel Hex file generation.

5. Proteus Simulation (Optional)

   • Open Proteus and configure the necessary hardware components for the simulation.
   • Double-click on the MCU component and load the compiled firmware (.hex file) into the virtual MCU.
   • Run the simulation to verify functionality.
   • Verify Operation
     - Upon start or reset, the system begins in Mode 1 (Normal).
     - Press Button 1 to cycle modes.
     - In Modes 2–4, use Button 2 to increment time, then press Button 3 to set it.

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8. Implementing on Hardware

Here is the demo of the traffic light system, showing real-time operation including mode transitions, time adjustments, and LED control. You can watch the full demo video here: VIDEO

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Thank you for checking out this project!
If you have any questions or suggestions, feel free to open an issue or submit a pull request.

Author