Vertically Inclined: UTRA Hacks Closed Challenge Submission

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

Awarded 2nd Place Overall and 1st for Top Track Performance.

Devpost: https://devpost.com/software/vertically-inclined

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

• Microcontroller: Arduino UNO R4 Minima
• Motor Driver: L298N dual H-bridge motor controller
• Sensors:
  • Ultrasonic distance sensor (HC-SR04)
  • Color sensor (TC3200)
• Actuators:
  • Servo motor
  • DC motors

Pin Configuration

Motor Driver (L298N)

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

Sensors

• Ultrasonic TRIG: 11
• Ultrasonic ECHO: 12

Project Structure

UTRA-main/
├── include                 // Non-library header files
│   ├── constants.hpp           // Pins and other constants
│   ├── devices.hpp             // Device constructors
│   ├── README
│   └── stations.hpp
├── lib                     // Custom libraries
│   ├── Arm                     // Servo arm library
│   │   ├── arm.cpp
│   │   └── arm.hpp
│   ├── Chassis                 // Chassis library
│   │   ├── chassis.cpp
│   │   └── chassis.hpp
│   ├── ColorSensor             // Color sensor library
│   │   ├── ColorSensor.cpp
│   │   └── ColorSensor.h
│   └── README
├── platformio.ini              // External dependencies
├── README.md
├── src                     // Source code
│   ├── build
│   │   └── Debug
│   ├── main.cpp                // main.cpp
│   └── stations                // Station autonomous routines
│       ├── station_a.cpp
│       ├── station_b.cpp
│       ├── station_c.cpp
│       └── station_d.cpp
└── test
    └── README

Dependencies

The following libraries are automatically managed by PlatformIO:

• L298N (v2.0.3) - Motor driver control
• DDBot (v1.1.3) - Differential drive control (wrapped by custom chassis class)
• Servo (v1.3.0) - Servo motor control (wrapped by custom arm class)
• 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 currentStation constant:

   constexpr Station currentStation = Station::STATION_A;

3. Available stations:
   • Station::STATION_A
   • Station::STATION_B
   • Station::STATION_C
   • Station::STATION_D
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: stations.hpp
void runStationA();

// Example: stations/station_a.cpp
#include "stations.hpp"

void runStationA() {
  Serial.println("Running Station A");
  // Move to blue tape
  while (chassis.readColor() != ColorName::BLUE) {
    chassis.followLine(ColorName::GREEN, false);
    delay(50);
  }
  // ...
}

Custom Chassis Methods

Full doxygen documentation available for each method

Movement

void moveTank(int leftSpeed, int rightSpeed, int time = 0, bool stopAfter = true);

void stop();

void followLine(ColorName lineColor, bool followLeft, std::pair<int, int> speeds = {170, 255}, bool reverse = false);

Utils

ColorName readColor();
ColorName getBufferedColor();

int readDistance();
std::queue<int> getDistanceReadings();

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, device initialization centralized in devices.hpp

Development

Adding a New Station

1. Forwards declare new method (e.g. runStationE()) in stations.hpp
2. Create new source file (e.g. station_e.cpp) in src/stations/ with source implementation
3. Add enum value to Station in stations.hpp: STATION_E
4. Update switch statement in main.cpp

Debugging

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

• Serial connection establishment
• Drivetrain pinmode setting
• Arm resetting

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.