WorldWide Rover

WorldWide Rover is an autonomous, globally accessible rover with a web interface for real-time control, maze navigation, and obstacle avoidance. The rover runs on a Raspberry Pi (server + GPIO) and an Arduino (motor control); the web app (React, AWS) talks to the Pi via ngrok so anyone with the link can drive it. My contribution focused on the server and backend: Flask API on the Pi, serial (UART) communication to the Arduino, and command handling so the front-end actions map reliably to rover movement. Demonstrates backend and API design, serial/hardware integration, and full-stack coordination in a time-limited hackathon (HackUMass XII — Best Embedded System).

Flask server and /move API The backend exposes a /move endpoint (POST) that accepts a direction (f, b, l, r, s for forward, back, left, right, stop). Request handling uses an action lock and a stop_event: when a new direction is requested, the server signals any in-progress action to stop, briefly waits, then sets the new direction and clears the stop flag. For stop (s), it sends the command once and returns; for move commands, it loops send_command(current_direction) with a 1 s delay until stop_event is set (e.g. user hits another direction). This keeps the rover responsive to new commands from the web UI.

Serial and Arduino The Pi sends commands to the Arduino over UART/serial (e.g. 9600 baud). The Arduino reads a character (f/b/l/r/s), drives motor pins (IN1–IN4 via an H-bridge or motor driver), and the rover moves. Serial connection is opened at server startup and closed on shutdown (e.g. atexit). Python uses a serial library (e.g. pyserial); the Pi also uses RPi.GPIO where needed for local signals.

Integration and deployment The web frontend (React) calls the Flask server; the server was exposed via ngrok so users worldwide could reach the Pi without port-forwarding. AWS hosted the frontend. Challenges the team tackled included latency for real-time feel, power management (12 V for motors), and reliable maze/obstacle avoidance with sensor calibration.