SunFounder DIY 4-DOF Sloth Robot Kit

Today we will have a look at a robot kit created by SunFounder. The Sloth is a bi-pedal robot based on the Arduino Nano. It utilises an ultrasonic module for obstacle detection and four servos for movement.

I found the kit to be an easy and fun build that took approximately an hour to complete. SunFounder have uploaded a YouTube video that serves as detailed introductions and assembly tutorial for the robot. It covers the entire assembly process, including the process to test the ultrasonic module as well as all the servos (before assembly), which is a good thing as one of the servos included with my kit turned out to be broken, but luckily I had a replacement servo on hand.

One thing to note is that the robot utilises two 18650 batteries, which after some research turned out to be commonly used in high-end flashlights and e-cigarettes, and are relatively pricey.

The robot can also be powered through the mini USB port on the Arduino (which I did while I waited for the batteries I had ordered to be delivered).

The code for the robot can be downloaded from here on the SunFounder website. Just note that the default code did not work for me as the ultrasound module did not detect obstacles. I rectified this by replacing the following code:

void loop()
{
 	int <span class="mceItemHidden" data-mce-bogus="1"><span class="hiddenSpellError" pre="int " data-mce-bogus="1">tooclose</span></span> = 0; // Define the test times, the initial value is 0
 	for(int a=0; a&lt;5; a++)  //for is a cyclical function and its cyclic times are determined by the second condition in the bracket. Here a&lt;5, a’s initial value is 0. When a&lt;5, run the program in the bracket. After running, a becomes a++ and it means adding 1 to a’s value.
	{
		delay(50); // Delay 50ms
		int din = sonar.ping_in(); // Call the ultrasonic transducer to read the distance that ultrasonic detected.
		if (din &lt; 7 &amp;&amp; din &gt; 0) tooclose++; // The smoothing. The times add 1 when the detect distance less than 7cm and greater than 0cm.
	}

With this:

void loop()
{
	int <span class="mceItemHidden" data-mce-bogus="1"><span class="hiddenSpellError" pre="int " data-mce-bogus="1">tooclose</span></span> = 0; // Define the test times, the initial value is 0
	for(int a=0; a&lt;5; a++)  //for is a cyclical function and its cyclic times are determined by the second condition in the bracket. Here a&lt;5, a’s initial value is 0. When a&lt;5, run the program in the bracket. After running, a becomes a++ and it means adding 1 to a’s value.
	{
		delay(50); // Delay 50ms
		int din = sonar.ping(); // Call the ultrasonic transducer to read the distance that ultrasonic detected.
		if (din &lt; 750 &amp;&amp; din &gt; 0) tooclose++;
	}

I really enjoyed assembling and playing with this little robot and would definitely recommend it to anyone interested in getting started in basic robotics.

SunFounder DIY 4-DOF Sloth Robot Kit

Dev Day 2016

veqjhvgb_400x400

On the Tuesday 27 September 2016 the first Dev Day occurred in Johannesburg South Africa. Dev Day is best described on their twitter page as “A community-owned and driven gathering of technologists, investors, hobbyists, engineers, artists, students and anyone with a strong sense of curiosity”. And I was invited to showcase some of the robots I have been working on. The event was extremely well organised with various people and Maker groups showcasing what they were working on as well as numerous speakers including Uncle Bob (Robert C. Martin). I really enjoyed the event and the experience of showing some of my work and the feedback and questions I received were amazing. It really was a great experience getting to talk and interact with similarly minded people. Many thanks to the organisers for a great event, hopefully one of many to come.

Here are some photos of my stand and the event.

Dev Day 2016

Book Review – Build Your Own Humanoid Robots

Book Cover

The first thing to note is that this book does not cover any Arduino-based robots. All the robots are based on PIC micro-controllers. Also note that this book goes into very low-level detail, even covering the fabrication of your own Printed Circuit Boards.

But even considering the above-mentioned I found this book extremely useful, not because of the electronic sections, but because of the mechanical build sections. 

The book shows exactly what raw materials to buy, what tools you will require and how to assemble the robots chassis and mechanical parts. And all these can easily be incorporated into an Arduino-based robot.

All six projects in the book can also be made to work with an Arduino without too much difficulty, all it will require is a bit of creativity and understanding of Arduino. 

For someone interested in Arduino based robots this book might not be the complete package, but the mechanical sections are some of the best I have ever seen in a book. If you are however interested in PIC-based robotics this book is a must buy.

Book Review – Build Your Own Humanoid Robots

Pololu Zumo 32U4 Robot

zumo32u4

In a previous post I looked at the Pololu Robot shield for Arduino, which was a robot shield on top of which a Arduino UNO R3 plugged into to form a great little autonomous robot.

Today we will be looking at the Pololu Zumo 32U4 Robot, a robot similar in size to the Zumo Robot shield for Arduino, but with quite a few changes. Firstly it no longer requires a separate Arduino board as it has an Arduino compatible micro-controller directly integrated into its main-board. It also has a LCD screen and IR proximity sensors which the previously mentioned robot did not have.

The Zumo Robot shield for Arduino came with 75:1 HP motors which produce average speed and torque. In the new Zumo I am installing 100:1 HP motors which are slower that the 75:1 HP motors but produce a lot more torque (which will be great for pushing in Robot Sumo matches).

Similarly to the Zumo Robot shield for Arduino the robot also has an expansion area that can be used to connect additional sensors and actuators. As with the Zumo Robot shield for Arduino various different operating source code can be downloaded from Pololu website, that changes the robot into anything from a sumo fighter to a line follower or even an auto-balancing robot, to name a few.

I bought the Zumo 32U4 Robot kit, which required assembly (unlike the Zumo Robot shield for Arduino that only required an Arduino to be plugged in). 

Here is a time Lapse of the robots assembly. 

I really like the Pololu Zumo series of robots and find them reliable, easy to develop for and a great deal of fun. There are various options available, from fully assembled to kit form depending what you are interested in.

zumos

And now that I have two, I can finally have some Robot Sumo fights, so expect some videos of that soon.

Pololu Zumo 32U4 Robot

IoT

I am starting an IoT project and wanted to share a little bit.  IoT or the Internet of Things is defined on Wikipedia as “the network of physical objects—devices, vehicles, buildings and other items embedded with electronics, software, sensors and network connectivity—that enables these objects to collect and exchange data. The Internet of Things allows objects to be sensed and controlled remotely across existing network infrastructure, creating opportunities for more direct integration of the physical world into computer-based systems, and resulting in improved efficiency, accuracy and economic benefit;”.  

To learn more I would recommend the book The Internet of Things Do-It-Yourself at Home Projects for Arduino, Raspberry Pi, and BeagleBone Black by Donald Norris. It provides an in-depth technical overview of concepts as well as some projects that can be built. The projects in the book are not particularly exciting but they do a good job at illustrating concepts and methods utilised.

Book

So I am going to be using a Raspberry Pi2 running Windows 10 IoT core, which will be communicating with some Arduino boards.

I am also looking at integrating with Azure Machine Learning to do some interesting things. 

I have not decided on many elements of the final project, but it will involve a robot.

rasp

On a side note, do not try to deploy Windows 10 IoT Core on a SD card using a Mac, it is a huge pain. My main computer I use at home (and for most of my development, blogging, video editing, etc.) is a MacBook Pro and in the end I gave up trying to get the deploy working and used my windows laptop which worked almost instantaneously.

Once I have decided exactly what I want to achieve and made some progress I will post more on this topic.

IoT

Insectbot Mini DIY Kit

InsectMain

I have previously built an Insectbot using instructions from the Internet, but subsequently DFRobot have created a kit that conveniently contains everything you need to build one without the need of finding and buying all the components individually.

InsectBoxOpen

This is a very easy little robot to assemble and is great for beginners, with one exception, the piece of plastic used for the robots head needs to be cut and holes made through, which sounds easy enough…. However do not be fooled, as it is the most brittle and fragile piece of plastic I have ever seen. Not breaking it is nearly impossible. Luckily it can easily be replaced with any other piece of flat plastic, such as a plastic container lid, etc.  

The robot uses a rechargeable battery, which is very convenient and comes with an adapter to charge via USB. 

InsectContent2

Here is a time-lapse video of the robots assembly.

The kit is relatively inexpensive and is a great little kit (with the exception of the plastic used for the robots head) and I would recommend it for anyone interested in getting started. The Beetle board used in the robot is fully Arduino compatible and can be developed for using the Arduino IDE.

A basic version of operating code can be downloaded from the products web page (http://www.dfrobot.com/index.php?route=product/product&product_id=1055#.Vtke2JN97fZ). This can be modified as much as you like to truly make the little robot your own.

Here is a video of the little guy in action. Just take note of one shortcoming, and that is that they really struggle to get traction when walking, so some custom shoes will help (I used some cork from a wine bottle, which I cut into little feet.) 

Insectbot Mini DIY Kit

Book Review – Robot Builder’s Bonanza

Many books have been written on the topic of robot building, ranging from very basic to extremely complex, but I have seldom come across a book that gets the balance right. Robot Builder’s Bonanza by Gordon McComb hits the sweet spot.

robotbook

The book provides a vast amount of detail on the electronics, mechanics and programming required to build a robot. Concepts like movement (for both wheeled and legged robots), sensors (to make your robot perceive its environment and conditions), the pros and cons of different Micro-controllers, as well as many other actuators (that allow the robot to change its environment in some way) are all covered. 

At the start of each section, a brief introduction to the field is given that includes explanations of key concepts (such as resistors and capacitors in the case of the electronics section) to the tools used (such as drills and screws in the case of the mechanical section). The book includes over 100 projects as examples to illustrate the concepts covered.

The book, in both print and content, is of very high quality. It is very clearly written and provides many diagrams, pictures and schematics, making it easy to understand even the more complex topics covered, for example robotic vision, robotic interpretation of sounds or the choice of which micro-controllers to use as your robots’ brain.

I would very highly recommend Robot Builder’s Bonanza to anyone interested in getting started in robot building or even someone who is currently building robots. It is not just a great book for learning the basics and getting started, but it is also a great reference guide to complex topics as well as a source of inspiration.

As far as Robotics books go this is one of the best, do yourself a favour and pick up a copy today.

Book Review – Robot Builder’s Bonanza