Yes, I also found it difficult to find a suitable supplier for gearbox motors. For my first robot I simply looked around on Amazon until I found one that ships to Ireland. For my second robot, I bought these motors here: http://www.active-robots.com/30-1-metal-gearmotor-37dx52l-mm. They are rather expensive, but they do work well, and they can be delivered to Ireland.

Simon B.

Thank you again for your help.
Regards,
D

You could use any motor shield which supports motor speed control. In reality you could use a H-bridge such as the L293D, but it just requires a number of extra steps to get working. It really depends on your experience of hobby electronics, and the type of micro-controller that you are using. If you are a beginner, I would recommend buying a motor controller shield, such as the Arduino Motor Shield, the Adafruit Motor Shield or the Ardumoto shield.

Simon B.

What could I use instead of arduino motor shield? Thank you so much for your help 🙂

From the info I can find on the internet, the L293D seems to be just a simple H-bridge. For a self-balancing robot you will need to be able to control the output speed of the motors, and the L293D on its own cannot do this. Here is a tutorial I found of how you can use the L293D and and Arduino in order to achieve bi-directional motor and speed control: http://letsmakerobots.com/files/MotorDriverL293Dnet.pdf

Hope this helps!
Simon B.

Hello Angela,
Thanks for your comment! 🙂 I am currently writing up the second post for this series, so hopefully that shall be ready soon. Making a self-balancing robot is really a fun way to learn the basics (and some of the advanced parts) of electronics and control theory…

Simon B.