Building the HUB-ee Buggy
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The Best Laid Plans
To understand how the HUB-ee Buggy works, it's probably best to start by breaking it down one component at a time:
The wheels, motors and drivers are built into the HUB-ee wheels so it's pretty obvious what function those serve. Without wheels and motors, this robot isn't going anywhere.
The wheels won't know where to go if there's no brain, and that's where the Redboard comes in! The Redboard is an Arduino-compatible development board based on the ATmega328 microcontroller. It'll take input from the Sharp IR sensor and give output to the HUB-ee wheels.
Speaking of the IR sensor, the Sharp GP2Y0A21YK is one of my favorite sensors for simple object detection and avoidance. It's an infrared sensor that detects objects by shining an infrared source and detecting the reflected light. Reading the output is really simple with a microcontroller like the ATmega328 that has a built in ADC because it outputs a voltage. This is how the HUB-ee Buggy will keep from bumping into things and getting stuck.
With only two wheels, the HUB-ee Buggy would tip over if there wasn't some support under it to keep it upright. The simple way to solve that problem is just to add a few stand-offs to prop it up as it scoots around.
The Protoshield PCB is really nice for small projects like this which are basically built on top of a development board. Not only will it allow us to wire things to the Redboard, but it will also serve as a base to which we can attach the wheels.
Finally, we need power to get this whole production moving. Originally, I thought that the LiPo Shield might be a good solution for this, but it just couldn't drive the wheels to my satisfaction. Thus, decided to keep it simple and pop on a AA battery holder.