Self-balancing robots look simple, but are difficult to build. The following video shows us how Hippodevices make self-balancing robots using Lego NXT and an Android device.
The Lego NXT motors you use must be strong enough to make the desired shaped robots easy to balance. Also, you need an Android ADK board to create communication between the Lego motors and your Android device. Hippodevices is using their own design, called the Hippo ADK which is currently available on Kickstarter.
This allows your Android device to read the status and control the Lego Motors. The last thing is programming it to balance according to the device’s gyroscope.
And since you already have a smart device on your robot, you can control it with another Android device!
Via : hackaday