Tri-Track Robot using TT-Motors and TV Remote Control

Hardware

• Microcontroller board, like ESP32 / ESP8266 / arduino Nano, etc (ESP32-WROOM-32)
• USB cable for the Microcontroller (Micro / Mini / Type C, to match your board)
• Blank prototype PCB (3 x 7 cm, or other sizes to match your board)
• PCB pin headers (male, female, sizes as needed)
• L298N DC Motor Driver x 1
• IR Receiver module x 1
• IR Remote control (can be a TV remote control)
• TT Motor x 2 (one-sided axis, speed ratio 1:120, the 'slower' type)
• 608Z bearing x 4
• 18650 recharagable batteries x 2
• spring plate set for battery holder x 2 (12 x 12)
• mini ON/OFF switch x 1
• 2 x 10 screws (some)
• 3 x 30 screws (2-4 pcs, with self-locking nuts)
• 2.6 x 8 self-drilling screws x 2
• 3 x 45 screws (2-50 pcs with self-locking nuts, optional)
• bamboo skewers for BBQ (3 mm diameter, to replace 3 x 45 screws)
• Drills (0.8-3 mm, various sizes)
• Dupont Wires
• heat shrink tubing (1-6 mm, various sizes)
• 8 x 124 rod x 2 (of iron/steel/plastic, can be 3D printed)
• 3D printer
• 3D Print filaments (PLA / PET-G / ABS)
• Glue

All needed hardware are available in Amazon, AliExpress, eBay, Walmart, or any online shops convenient to you.

Software

• Arduino IDE
  ESP32 Driver by Espressif Systems (use 2.0.17; 3.0.x is known to clash with other libraries)
• IRremote library
  https://github.com/Arduino-IRremote/Arduino-IRremote
  (download zip and "Add .ZIP Library" in IDE)

Required skills:

• 3D printing
• 3D modelling, if you have to modify the given models
• programming in Arduino IDE
• electronics soldering

No need to reinvent the wheels

• Track_Plate.stl
  https://www.thingiverse.com/thing:14599

• new-608_idler_sprocket.stl
  https://www.thingiverse.com/thing:1209486

• Battery holder with ON/OFF switch
  https://www.thingiverse.com/thing:6675466

Net weight (without battery) of the robot: 450g

This RC model is based on TOM's track links and wheel system which is popular and reliable.

I choose to use TT motors as engines because it is at a lower cost and very flexible in voltage needs. The motors can be powered by a pair of 18650 batteries (in serial connection about 8V) without needing to convert it to 5V or 12V before use. The best companion for TT motors is L298N DC motor driver module. It serves two purposes in one unit. First, it controls two DC motors allowing change of motor speed and direction by the microcontroller. Second, it has a built-in voltage convertion chip to supply a constant 5V output (separated from the motor power supply) which supplies power for itself and can also power up the microcontroller.

L298N is capable of simultaneous control of two DC motors, ideal for this tank project which requires exactly two motors.

A wide variety of microcontrollers are compatible with L298N. To control two motors it needs 4 to 6 digital I/O pins. I used 4 pins only. If you plan to have extra sensors or connectors, you need extra I/O pins for these components. In this project I used an IR receiver occupying one I/O pin, so that I totally need 5 empty pins available on the microcontroller. A low-cost Arduino Nano is great for this purpose. I used ESP32 instead because this bigger chip has built-in wifi and bluetooth connections. It gives a bigger potential for upgrading in the future to include RC through wifi or bluetooth.

An IR Receiver module is added to allow using any IR remote control as the controller.