When I kicked off ROSbots, I wanted to design a ROS+OpenCV Raspberry Pi robot as cheap as possible — less than $100. You get what you pay for.

The ROSbots version 1.0 kit (still currently listed on our site as of 12/19/2017) had all the necessary components to get the robot to move. But that’s about all it did and bellyflopped on the rest.

ROSbots v1.0 not doing a good job bellyflopping

But before I beat down on the poor robot… (btw — here are the build instructions for the v1.0 kit for reference)

What did I like about 1.0?

Maker Accessible — It was based off a Raspberry Pi 3. Cheap. Wireless. Purchaseable from many sources. Maker Hackable — It used Raspbian Lite. Lightweight. Widely supported. As a matter of fact, you can set up your Raspberry Pi with the Raspbian Lite disk image we built with ROS + OpenCV pre-installed. Maker Budget — Other than a simple laser cut platform for the Raspberry Pi, it used standard chassis parts, hardware, and wires which can be easily sourced by many overseas suppliers. *No* Maker-Oh-Crap-Mods— We didn’t need tape to hold things down (though there is a tiny bit of velcro involved).

What didn’t work about 1.0?

The Raspberry Pi GPIO pins lack hardware interrupts as well as extensive PWM support. This made it very difficult to reliably read the encoder ticks for speed and to pulse the motors without sucking up precious CPU cycles. You have to physically take the 4xAA batteries (which power the ROSbots’ motors) out of the ROSbots battery pack to charge / change. Most standard 5v USB power banks (which powered the Raspberry Pi) don’t allow you to charge and discharge at the same time. So we had to shutdown the Raspberry Pi whenever we wanted to charge up the power bank.

Paving the way for ROSbots version 2.0

Having hardware that couldn’t make it move reliably and having a power system that required human intervention is simply unacceptable for what would be an “autonomously moving” robot.

ROSbots version 2.0 sneak peak!!

I’m in the process of finalizing the parts needed for ROSbots version 2.0 which will address the issues I had with 1.0 while still sticking to the “Maker Mentality” of using accessible components which inevitably results in an affordable kit for those with a “Maker Budget”.

A Pi camera will also be included from the start. Stay tuned for the version 2.0 update post coming shortly.

In the meantime, if you’re a Maker too, have thoughts, comments, or would just like to say hi, please reach out.

Thanks!

Jack “the ROSbots Maker”