2WD Obstacle Avoiding Robot Kit - DIY Ultrasonic Robotic Project

Technical Details

• Chassis Thickness: ~3mm Acrylic.

• Dimensions: ~200mm x 150mm (Assembled).

• Included Hardware: M3 Screws, Nuts, Spacers, and Motor Brackets.

Prototyping and Engineering Tips from Robogears

• The "Servo Scan" Upgrade: For more advanced navigation, mount the Ultrasonic sensor on a small SG90 Servo Motor. Instead of the whole robot turning to "look" for a path, the servo can sweep the sensor 180 degrees to find the widest opening before the motors even move.

• Power Management: Geared motors can create "noise" in the circuit that causes Arduino resets. Always use two separate power paths if possible: one for the logic (9V battery or Power Bank) and one for the motors (AA batteries). If using a single source, add a large 220uF capacitor across the power rails to smooth out voltage dips.

• Sensor Shielding: The HC-SR04 can sometimes give "false positives" if it's picking up ultrasonic reflections from the robot's own chassis or the floor. Ensure the sensor is mounted at the very front edge and angled slightly upward if operating on thick carpets.

• Coding Logic: Start with a simple "Stop and Turn" logic. Once that works, implement "Proportional Slowdown"—where the robot slows down as it gets closer to an object—to make the movement look more natural and "organic."

• Weight Distribution: Place your heaviest component (the battery pack) in the center or slightly toward the drive wheels. If the robot is too "nose-heavy," the caster wheel will create excessive friction; if it's too "tail-heavy," the drive wheels might lose traction and slip.

Package Includes

• 1 x Transparent Acrylic Chassis Set

• 2 x Geared BO Motors with Wheels

• 1 x Caster Wheel (Universal Wheel)

• 1 x HC-SR04 Ultrasonic Sensor Module

• 1 x HC-SR04 Mounting Bracket

• 1 x Battery Holder + 2 18650 Cells

• Complete Set of Screws, Nuts, and Standoffs

Disclaimer: This is a DIY kit and requires assembly. Soldering may be required for motor leads. The microcontroller (Arduino/Nano) and motor driver (L298N) are often sold separately or as part of an expanded bundle; please verify your specific kit contents. Always double-check wiring polarity to avoid damaging the sensor or controller.