LOTHYE D2-1 Line Tracking Robot Car DIY Soldering Kit

LOTHYE D2-1 Smart Line-Tracking Robot Car — DIY Soldering Kit

Build your own intelligent line-tracking robot car from scratch! The LOTHYE D2-1 Smart Robot Car Kit is the perfect hands-on project for electronics enthusiasts, hobbyists, students, and anyone who wants to learn real-world circuit assembly through a fun, rewarding build. Powered by an LM393 dual voltage comparator and a pair of photosensitive (light-dependent) resistors, this car autonomously follows a black line on a white surface using closed-loop motor control — all without a microcontroller!

⚠️ Please Note: This kit is designed for buyers who have experience with electronics and soldering. Success after assembly depends on the builder's skill. The kit is verified to be in good condition before shipment, but a 100% post-assembly success rate cannot be guaranteed. Please read all instructions carefully before purchasing.

🔋 Batteries are NOT included. Two (2) AA batteries are required.

Made in Mainland China.

How It Works

Two photosensitive resistors mounted at the front of the car detect light reflected from the surface below. When the car drifts off a black line onto the white background, the difference in light reflectance creates an imbalance in resistance readings. The LM393 comparator IC instantly detects this imbalance and signals the corresponding DC gear-motor to stop while accelerating the opposite motor — steering the car back on course. The entire correction happens in a fast, sensitive closed feedback loop.

Key Features

• LM393 Comparator IC: Dual precision voltage comparator provides rapid, sensitive closed-loop line detection and motor correction.
• Photosensitive Resistors: Detect differences in light reflectance between white and black surfaces — the core sensing element of the tracking system.
• DC Gear-Reduction Motors: Custom-integrated reduction gears deliver optimal torque and speed so the car stays controllable and responsive.
• Acrylic Wheels + Silicone Tires: Three-piece black acrylic wheel assemblies with silicone rubber tires for smooth traction.
• Universal Front Caster Wheel: Enables smooth directional changes during tracking corrections.
• Soldering Practice Included: Hands-on soldering of resistors, capacitors, transistors, LEDs, and the LM393 IC — a fantastic skill-building experience.
• Educational Value: Covers photocells, voltage comparators, motor driver circuits, PCB assembly, and mechanical integration in a single project.
• Runs on 2 × AA Batteries (3V total) — not included.

Assembly Overview (4 Steps)

1. Circuit Soldering: Solder components in order of height — resistors first, then capacitors, transistors, LEDs, and finally the LM393 IC. Verify polarity on all polar components. Use a multimeter to confirm resistance values.
2. Mechanical Assembly: Mount the universal caster wheel to the PCB, attach the battery box with double-sided tape, and wire the power leads (red = 3V+, yellow = GND).
3. Wheel & Motor Assembly: Assemble three-piece acrylic wheels, fit silicone tires, and fix motors to the PCB with adhesive. Solder motor leads with sufficient length for easy rewiring if needed.
4. Opto-Electronic & Debugging: Mount photosensitive resistors and red LEDs ~5mm above the ground. Insert batteries, flip the switch to ON, and test tracking behavior. Swap motor wiring if the car reverses unexpectedly.

What's in the Box

• 1× D2-1 Smart Robot Car Complete Kit (all PCB and mechanical components)
• Batteries NOT included (2 × AA required)

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Frequently Asked Questions

Q: Is this line-tracking robot car kit suitable for beginners?

A: The D2-1 line-tracking robot car kit is best suited for builders who already have basic electronics and soldering experience. You will need to solder resistors, capacitors, transistors, LEDs, and an IC chip, and verify component polarity throughout. Complete beginners may find it challenging without prior circuit knowledge. It is an excellent intermediate-level educational electronics kit.

Q: What batteries does the D2-1 smart robot car require?

A: The D2-1 robot car kit requires two (2) standard AA batteries, which provide approximately 3V of power. Batteries are not included in the package and must be purchased separately.

Q: What electronics concepts will I learn by assembling this DIY robot car?

A: Assembling the D2-1 smart tracking car teaches you how photosensitive (light-dependent) resistors work, how the LM393 dual voltage comparator IC compares two input signals, how DC gear-reduction motors are driven and controlled, how a closed-loop feedback circuit functions in real-time, and fundamental PCB soldering and mechanical assembly techniques.

Q: Does the kit include a track or runway for the line-tracking car?

A: No, a track is not included. You can easily create your own track by drawing or taping a black line on white paper or cardboard. The car's photosensitive sensors are optimized to distinguish between a black line and a white surface for reliable tracking.