Arduinos are cool, but what about Raspberry Pis and BeagleBones? I recently came across the BeagleBone OMAP eval/hobbyist system from TI. With a 1 GHz ARM core, all the ports needed to hook it up quickly and get to work, and a price tag of $45, it’s looking like a pretty nice alternative to the Arduino for folks that already know how to program in a linux environment.
It also looks like a very nice simple data acquisition system for laboratories and hobbyists. The BeagleBone’s ADC has a sample rate of 125 ns which comes out to eight million samples per second. A digital sample rate that engineers at national labs in the ’90s would have killed for or at the very least, spent thousands of dollars for. The Raspberry Pi is cheaper than the BeagleBone, but it doesn’t have a built-in ADC. There are, however, resources available for attaching an auxiliary ADC to the board.
On the hobbyist side of things, a simple somewhat low-bandwidth digital oscilloscope wouldn’t be too much of a stretch project with the board as is. A project is already in the works to press the board into ham radio service as a software defined radio. For excellent information on building a software defined radio from scratch check out this series of videos from Jerri Ellsworth. While availability of an on-board hdmi output port makes the dream of a smart phone display slightly obsolescent, with both host and client USB capability, it should be easier to use a smart phone as a display with a Beagle Bone than it would be with an Arduino system.
The board computers look great for getting to work on a project if you have computing experience, but the Arduino still looks like the best choice for getting your hands dirty at the pin level. Documentation for the board computers was rife with warnings about not exceeding I/O and ADC voltage levels. While this is still a concern with the Arduino, error recovery is much simpler, at least on the plug-board based system I’ve been using.