T.A.R. (Tactical Autonomous Rover)

Overview

T.A.R. is an Arduino Uno–based, 4-wheel-drive robot car that supports Manual, Automatic, and Voice-assisted control. The firmware is built around a non-blocking finite state machine (millis-based) so the robot can keep responding to Bluetooth commands while scanning for obstacles.

Operating modes

• Manual: Bluetooth app buttons control direction + speed, with a continuous safety override when driving forward.
• Automatic: Ultrasonic + servo scanning for obstacle avoidance and path selection.
• Voice (via Android app): Speech-to-text happens on the phone; the app sends the same serial commands as Manual mode.

Hardware Architecture

• Microcontroller: Arduino Uno Rev3
• Motor Driver: L298N Dual H-Bridge
• Actuation: 4x DC TT Gear Motors (Configured for Skid-Steering)
• Sensors: HC-SR04 Ultrasonic Sensor mounted on an SG90 Micro Servo
• Communication: HC-05 Bluetooth Module (SPP)
• Power Source: 2x 18650 Li-ion Batteries (7.4V Total)

Software Features

• Non-Blocking Auto Mode: Utilizes millis() instead of delay(), allowing the rover to continuously listen to incoming Bluetooth interrupts even during complex servo sweeping maneuvers.
• Continuous Safety Radar: In Manual Mode, the rover actively pings the ultrasonic sensor while driving forward. If an obstacle appears within 40cm, it automatically cuts power to the motors to prevent a collision.
• Voice-Control Ready: The architecture is decoupled. Voice recognition will be handled by a companion Android application (via Speech-to-Text), which translates spoken words into the standard Manual Mode serial commands below.

Documentation

• Wiring reference (pins + power routing): docs/Wiring_Reference.md
• Circuit diagram (SVG): docs/TAR_Circuit.svg
• Project PDF used as a source: docs/reference/TAR_Doc.pdf

Circuit diagram

Repo structure

• src/: Arduino firmware (TAR_Main.ino)
• docs/: wiring docs + circuit diagram
  • docs/images/: build/demo photos
  • docs/reference/: source material used to build the documentation

Bluetooth Controller Mapping

Use any standard Bluetooth Terminal or Gamepad app (e.g., "Serial Bluetooth Terminal").

Movement Commands (D-Pad)

• Forward: G
• Backward: H
• Left: I
• Right: J
• Stop: K (Set this to the "On Release" action for all D-Pad buttons)

State & Speed Overrides

• Enable Auto Mode: A
• Enable Manual Mode: M
• Emergency Stop / Idle: O
• Speed Fast (200 PWM): X
• Speed Medium (150 PWM): Y
• Speed Slow (100 PWM): Z
• Print System Status: ?

Build & Upload

1. Open src/TAR_Main.ino in Arduino IDE.
2. Select Board: Arduino Uno.
3. Select the correct Port and upload.

Notes

• The firmware uses SoftwareSerial on pins 10 (RX) and 11 (TX) for the HC-05.
• Power the motors from the battery pack through the L298N; distribute 5V/GND to the Arduino + sensors as described in docs/Wiring_Reference.md.

Photos

Project photos are stored in docs/images/.

Team

Spring 2026 (Faculty of Computers & AI, Minia National University)