UTRA Robotics Control System

A modular robot control system built with Arduino framework and PlatformIO for autonomous navigation and task execution across multiple stations.

Overview

This project provides a software control hub for a mobile robot platform designed to execute various station-based tasks. The architecture emphasizes clean separation of concerns, software-driven configuration, and deterministic behavior execution.

Hardware Requirements

• Microcontroller: Arduino UNO R4 Minima
• Motor Driver: L298N dual H-bridge motor controller
• Sensors:
  • Ultrasonic distance sensor (HC-SR04 or compatible)
  • Color sensor (optional, library included)
• Actuators:
  • Servo motor
  • DC motors for drivetrain

Pin Configuration

Motor Driver (L298N)

• EN_A: Pin 9
• IN1_A: Pin 2
• IN2_A: Pin 3
• EN_B: Pin 10
• IN1_B: Pin 4
• IN2_B: Pin 5

Sensors

• Ultrasonic TRIG: Pin 11
• Ultrasonic ECHO: Pin 12

Project Structure

UTRA-main/
├── src/
│   ├── main.cpp              # Main program dispatcher
│   ├── movements.cpp/h       # Robot movement control
│   ├── robot_mode.h          # Mode enumeration
│   ├── ultrasonic.h          # Ultrasonic sensor wrapper
│   ├── StationA/             # Station A task logic
│   ├── StationB/             # Station B task logic
│   ├── StationC/             # Station C task logic
│   └── StationTest/          # Testing routines
├── lib/                      # Custom color sensor library
├── include/
│   └── constants.hpp         # Hardware pin definitions
└── platformio.ini            # Build configuration

Dependencies

The following libraries are automatically managed by PlatformIO:

• L298N (v2.0.3) - Motor driver control
• Servo (v1.1.8) - Servo motor control
• NewPing (v1.9.7) - Ultrasonic sensor interface

Building and Uploading

Prerequisites

• PlatformIO installed (via VSCode extension or CLI)

Build

pio run

Upload to Robot

pio run --target upload

Monitor Serial Output

pio device monitor

Usage

Selecting a Station

To change which station the robot executes:

1. Open src/main.cpp
2. Modify the START_MODE constant:

   constexpr RobotMode START_MODE = RobotMode::STATION_A;

3. Available modes:
   • RobotMode::STATION_A
   • RobotMode::STATION_B
   • RobotMode::STATION_C
   • RobotMode::TEST
   • RobotMode::IDLE
4. Re-upload the code to the robot

No other code changes are required.

Implementing New Station Logic

Each station has its own subdirectory with implementation and header files:

// Example: StationA/Station_A.h
#pragma once
void runStationA();

// Example: StationA/station_A.cpp
#include "Station_A.h"
#include "movements.h"

void runStationA() {
  moveForward(1000);
  turnLeft(500);
  // Add your station logic here
}

Available Movement Functions

void moveForward(int duration);    // Drive forward (ms)
void turnLeft(int duration);       // Rotate left (ms)
void turnRight(int duration);      // Rotate right (ms)
void raiseArm();                   // Raise servo arm
void lowerArm();                   // Lower servo arm
int checkDistance();               // Get ultrasonic reading (cm)

Design Philosophy

• Software-Driven Configuration: Change behavior by modifying a single constant
• Modular Architecture: Each station is self-contained and isolated
• Deterministic Execution: All logic runs once in setup(), not in loop()
• Clean Separation: Hardware pins centralized in constants.hpp

Development

Adding a New Station

1. Create a new directory: src/StationD/
2. Add header file: Station_D.h with function declaration
3. Add implementation: station_D.cpp with logic
4. Add enum value to robot_mode.h: STATION_D
5. Update switch statement in main.cpp

Debugging

The robot waits 2 seconds after setup() begins, allowing time for:

• Serial connection establishment
• Physical placement and preparation

Monitor serial output at 115200 baud for debugging information.

License

This project is a winning submission of the UTRA (University of Toronto Robotics Association) 2026 hackathon.