5. Operating the Electric Motors

Transistor-based DC Motor Control

The best way to work with the DC motors is to use a specialized Motor Shield.

At first - we did not have it. But still, we were desperately eager to try our new chassis in action.

We were lucky - while building our starting kit, we took a couple of NPN transistors 2N2222A. Here and here we found a nice and short explanation how to use a transistor to control high currents of the DC motors without the risk to damage the Arduino board.

4. Arduino MEGA 2560

WHY?

The grandiosity of the plans we have for our mighty robot raised some concerns. Can a single Arduino UNO carry on all the tasks we expect? At that time we did not trust much the wires-saving technologies like I2C or SPI. So we thought, first of all, we will quickly run out of available Arduino ports.

3. Chassis Selection

The Plan

Preparation steps may take a lot of time. I and my son spent more than two months learning the basics and running small experiments with Arduino. We used a custom-built starting kit, passed a couple of beginners ramp-up courses, played with Arduino board, sensors, LED and electric motors driven by transistors. Ultimately, we figured out what can we expect from the Arduino-based robot, and what kind of the tasks it can perform.

We decided to build a rather big robot which should be able to wander around the rooms. It needs to be capable going over 5 cm (2 inches)  doorsteps (because that is the height of the doorsteps in our house. Also, the robot must be stable and capable of wearing lots of sensors, a video camera or a cell phone, and/or some small TFT screen. Imagination instantly paints some caterpillar-chassis robot 10 cm high and 20x20 cm long and wide (~4x8x8 inches).

2. Dive into the Arduino Programming

Too many choices - too many decisions

The openness of the Arduino platform gives the unprecedented flexibility. Anyone can find own combination of tools and approaches which fit best his or her level and preferences. This also brings some complexity. Usually, it is hard to find information about all available options in a single place. So, for most of us, it takes many trial and error attempts. If the "errors" path is too long - it gets harder and harder to stay motivated and keep going.


We are not going to provide a training here - there are lots of specialized resources which do this much better. Our goal is to make your learning path as short as possible and gain enough knowledge to understand and enjoy the next steps in our robot building challenge.

1. Dive into Electronics

Required Knowledge

Nowadays the entry barrier for robotics is not high. To start building some simple robots it is sufficient to know the very basic electricity principles, have the preliminary idea about how to use a computer, how to browse the Internet and work with documents.

You won't even need any soldering skills!

Still - any kind of extra knowledge will be extremely helpful for you. If you are keen to take your robotics hobby seriously but feel the lack of the core knowledge - consider participating in the basic online training like this one: Khan Academy: Electrical Engineering. The foundation Programming training can also be helpful.

0. Introductions

A while ago, me and my 10-years old son fell in love with the idea of building robots and implementing some electronics tricks to amuse ourselves and amaze others. Of course, our ambitions did not reach the level of constructing smart and autonomous Boston Dynamics-like beasts. We would like to create something small and friendly which will be wandering around our house and play soccer with our cat.

First, our imagination painted some noble and intelligent robot like the famous R2D2.