Starting from SCRATCH

July 2013
By Bryan Bergeron

“How do I start my students/children down the road of robotics?” is a common question in my inbox. It’s a difficult question to answer. Not for lack of options, but because there are so many options available. As with most things, the ‘best’ solution depends on budget, existing infrastructure, and the overall goal.

For example, let’s say you’re a first grade teacher with a few desktop computers in your classroom. If your goal is to introduce programming concepts and eventually branch out to sensors and hardware control, then you should explore the SCRATCH language. SCRATCH is a graphical programming language that makes it easy for anyone five years and older to create interactive stories, animations, games, music, and art, and then to share their creations on the Web.

Best of all, SCRATCH is free. It was developed at the MIT Media Lab with financial support from the National Science Foundation, Microsoft, Intel Foundation, MacArthur Foundation, Google, Iomega, and the MIT Media Lab research consortia. Check out the site (info.scratch.mit.edu) for more information, including YouTube tutorials, hundreds of examples, books, and hardware. Version 2.0 is currently in beta but the full SCRATCH 2.0 should be available by the time you read this.

If your goals include teaching young children or students how to integrate sensors and effectors in software, then consider the PicoBoard ($45) from SparkFun. The SCRATCH-compatible board — based on an ATmega328 running at 16 MHz — contains a phototransistor, microphone, button, and slider, as well as four additional inputs that can sense electrical resistance. Setup is simple — connect the USB device to your computer, download the drivers, and start programming. Motors, additional sensors, and other hardware add-ons (available from the SCRATCH store) are inexpensive. Another great feature is the PicoBoard Simulator program (http://scratch.mit.edu/projects/chalkmarrow/188919) that allows you to experiment with a simulated board before you actually buy one.

I like the SCRATCH/PicoBoard combination, in part because there’s a natural growth path to the Processing/Arduino combination. Processing shares many attributes with SCRATCH, but is much more powerful. It’s also text based, and so may be more intimidating for novices.

If your students/kids are a little older, then consider the book Python for Kids: A Playful Introduction to Programming. I wish that this book had been available when I first learned the language. Python is free and runs on the most popular operating systems. However, if you or your school don’t have a computer available, then consider investing in a few Raspberry PI microcontrollers ($25). The downside of this combination is that you need to create a desktop environment — that means a mouse, keyboard, and HD monitor. While miniature monitors are available, a decent one will cost $100 and up. Still, it’s hard to beat the Raspberry PI’s mix of affordability and power. I paid over $1,000 for a less capable Linux board to use on one of my robot projects only a few years ago. Unlike that board, there are a variety of shields — including Arduino-compatible shields — available for the Raspberry PI. SV

July 2013
By Bryan Bergeron