If you have an interest in robotics, it can be really difficult to know where to start. There are so many designs and kits out there that it becomes overwhelming. But it is best to start with the basics and then expand from there after you learn the ropes. One way to do that is by building MertArduino’s adorable app-controlled robot dog.
This is a little more complex than a typical line-following rover kit, but it is still approachable for beginners. It uses eight inexpensive MG90S hobby servo motors to walk on four legs, plus one more servo to rotate the head. The tutorial explains how to create a smartphone app for controlling the robot and there is an ultrasonic sensor hidden in the dog’s eyes to help it detect obstacles.
To construct this robot, you will first need to 3D print the body, legs, and head. Those parts are small enough to print on almost any model of 3D printer. You’ll then need the custom PCB, onto which all of the electronic components attach. You can order that from any PCB fabrication service. Using basic through-hole soldering techniques, you can populate that PCB with an Arduino Nano board, an HC-05 Bluetooth module (for communication with a smartphone), and various miscellaneous components like resistors and a voltage regulator. Power comes from a pair of 18650 lithium battery cells.
After assembly, you can begin controlling the robot using the provided app. Or you can follow the instructions to make your own app with the help of MIT’s handy block-based Scratch programming tool.