This project implements an RTOS-based robotic car controlled via PS4/PS5 controllers over Bluetooth. The main processing is handled by the NXP KL25Z (MKL25Z4) microcontroller, while an ESP module provides Bluetooth connectivity—transmitting controller commands via UART at 9600 baud to the KL25Z. The system integrates real-time control of motors, LEDs, and audio. It features two distinct driving modes and a weight distribution configuration that places most of the mass at the front, significantly enhancing turning performance. Our robot set a run time of 18.49 seconds.
- Edwin Hein Tun - ESP Module (Controller Program and UART Integration)
- Liu Jia Quan - LED Programming
- Low Jun Chen - Motor Control and LED Integration
- Ng Chee Fong - RTOS and UART Communication
- Viswanathan Ravisankar - Buzzer and Main Driver Functions
- Driving Modes:
- Normal Mode:
Allows smooth navigation with curved and single-wheel turns. The forward-weighted design aids in better rotation during one-wheel turns. - Tank Mode:
Enables on-the-spot two-wheel turns for precise maneuvering in tight spaces.
- Normal Mode:
- Supports movement in all four directions (Forward, Backward, Left, and Right).
- Automatically stops if no command is received.
- Front LEDs (8 Green):
- Display a sequential “running” animation while the robot is in motion.
- Remain fully lit when the robot is stationary.
- Rear LEDs (8 Red):
- Flash at a rate of 500 ms ON/500 ms OFF when moving.
- Flash at a faster rate of 250 ms ON/250 ms OFF when stationary.
- Continuous playback of a tune during operation.
- A unique completion tone is played at the end of the challenge run.
The project uses the Bluepad32 library to enable PS4 and PS5 controller support via Bluetooth. The controller allows you to:
- Adjust speed via the D-pad.
- Control movement and turning using joysticks and triggers.
- Toggle between driving modes (Tank Mode and Normal Mode) and change LED/audio states using dedicated buttons.
The system’s architecture is built on FreeRTOS/CMSIS-RTOS2, which manages multiple concurrent tasks:
- Brain Task:
Processes incoming controller commands. - Motor Task:
Manages movement based on commands and drives the motors through the DRV8833 motor driver. - LED Task:
Updates the LED animations according to the robot’s movement and status. - Sound Task:
Handles continuous audio playback, including the finish tone.
Tasks synchronize using semaphores to ensure smooth and conflict-free operation.
- Main Microcontroller: NXP KL25Z (MKL25Z4)
- Communication Module: ESP module (for Bluetooth connectivity, transmitting at 9600 baud via UART)
- Motor Driver: DRV8833
- Motors & Chassis: DC motors with a robust chassis design
- LEDs: 8 Green (front) and 8 Red (rear)
- Controller: PS4/PS5 Bluetooth Controller via the ESP module
- Audio: Piezo Buzzer
- Watch our detailed project walkthrough and demonstration on YouTube!
