If you’ve always dreamed of making your own robot or love the STEMI Hexapod bot but never had the technical know-how to do so, then boy do I have just the robotic dog for you.
The Bittle may not be the giant, Gundam-sized mech of your dreams, but it’ll definitely get you started in the field of robotics. The second project of Petoi, the creators of the open-source robotic cat Nybble, this four-legged robot dog requires you to assemble the body, program its systems, and hopefully share what you have created with other Bittle owners.
Building the Body Frame
Assembling the body requires you to interlock the different 3D printed parts. These symmetrical parts have as little screws as possible and have simple, color coded patterns to make assembling the physical body much easier. Once completed, your robot dog will measure 20cm x 11cm x 11cm and weight less than 280g
I’m sure some of you will ask how much damage this toy can take, and the answer is not much. Though the Bittle’s 3D printed parts have incorporated high strength injection mold plastic to help it with falls, collisions, and allow it to carry up to 450g weights under its belly, it is still a fragile little robot dog and must be treated with care (as you should treat all your robot pets).
The Actuator, The Battery, and The Camera
Nine P1S servos actuate the Bittle and provide its movement capabilities. These small but quick servos have a controllable angle of 270°. Eight of the servos are attached to the Bittle’s legs for walking, while the final servo is located in its neck so it can pan its head in different directions.
To help the Bittle “see”, an intelligent camera running on an ESP32 dual-core processor with visual recognition algorithms is placed on the dog’s face. With it, the robot can recognize patterns, objects, and movement at a rate of 25-50fps. You can even see what it sees by streaming the video feed through WiFi.
Before gettinng to the electronics, take note that the robot runs on a customized Lithium-ion battery located on Bittle’s belly. The power pack has a slide-in installation and anti-reverse plug for easy battery swapping. With the battery installed, the Bittle can walk non-stop for at least an hour before needing a recharge.
The Electronics
The Bittle works on a NyBoard V1, which is a modified Arduino board with extra peripherals attached to it. With it, the Bittle can accomplish complex dog-like motions such as sitting, hopping, and kneeling just to name a few.
The board drives at least 12 PWM servos (which is more than enough to handle the Bittle’s 9 PIS servos) and has an Inertial Measurement Unit (IMU) which has the ability to “store” the robot’s actions and optimize its balance whilst doing tricks.
When you combine the NyBoard V1 with the mounted Raspberry Pi, the Bittle can take in more sensory data, connect to the Internet, and even make certain decisions autonomously. Couple this with Bluetooth support for uploading codes and commands and a WiFi dongle, and you have yourself a robot which you can control wirelessly via your smartphone or computer.
The Software
Bittle runs on the current version of the OpenCat code created by Petoi. It has over 3,000 lines of Arduino code and can be programmed using different coding environments.
To make coding easier for beginners, Petoi collaborated with STEM education company TinkerGen to provide free coding lessons in Codecraft (TinkerGen’s graphical coding environment) specifically for the Bittle.
Petoi heavily encourages the showcase and sharing of owners’ Bittles, so much so that they created a forum on their site to discuss DIY models, different modules, repair tutorials, and updates to the project as it gets more and more advanced. There are even plans to hold contests to see whose Bittle can accomplish certain feats the best (such as who can make the highest jumps or who can race down a track the fastest).
It took over two years to develop the Bittle and soon, the world will now have their own robot dogs to assemble and program. As of now, there are only 7 days left in the Bittle’s Kickstarter campaign. In this time, it has managed to raise over $470,000, more than nine times its initial Kickstarter goal of $50,000. If you would like to own a dog but can’t handle the responsibility of feeding or looking after it, then maybe a miniature robot dog is just what you need.
