This post from system integrator Avanceon's Brian Fenn originally appeared on Monday this week. But in celebration of Pi Day, it seems only appropriate to bring it back up to the top. Learn more about what the Raspberry Pi can do for automation control. Then go grab yourself a piece of the edible pie.
No, Raspberry Pi is not a reference to a waistline-expanding treat, but rather a small, affordable computer that you can use to learn programming. Often thought of as a controller replacement (which it can certainly be), the Raspberry Pi is an interesting tool because it allows for simple connectivity for communication and data collection. Over the past few years, I’ve been having some fun exploring ways to adapt Raspberry Pi for both home and industrial applications.
I purchased an older house several years ago and made a number of “interesting” discoveries. One of the most annoying was that my outdoor lights were controlled by a single light switch located at the far end of my garage. Because I had to walk across the entire house, often down several flights of stairs, in order to turn them on, I was typically coming home in the dark. So I decided to use a Raspberry Pi to allow me both manual and automated control of my outdoor lights.
Stealing a few late-night hours, I found a couple primers online on how to control lights via an infrared sensor, cobbled together some code, and bread boarded up a couple of LEDs to simulate my outdoor lights. It took some thought and tinkering, but I made it work.
It ended up being a really fun project that I got into, and I have a bunch of ideas about how I want to continue to build it out and enhance it. But the reason I bring it up here is that I think it helps to highlight some of the capabilities and applications of unconventional controllers in the manufacturing space.
Certainly, if you’re facing environmental constraints, performance requirements, lots of I/O demands, etc., you are going to want to stick with your traditional controllers. But if you need to pick up a few I/O for data purposes, or interact with the web or data, or develop other small and non-critical types of applications, the Raspberry Pi and other devices of its ilk represent a great alternative. They have a lot of capabilities, they’re easy to use and program, and are easily replaceable from a reliability/maintenance perspective.
I recently spoke with a customer that was looking to do some checking on packaging material to ensure the right product was ending up in the right package. They were looking at some scanner solutions that could handle all detection and signaling of an issue, but they needed to be provided with the proper barcode and other related order information. In the past, we might have used a small programmable logic controller (PLC) to handle the Ethernet communications to and from the scanners and some of the signal processing coming out of them. The scanning devices had on-board relays that could be wired to the existing control system to stop conveyance or annunciate a mismatch, etc., so we only needed to solve for the communication from an existing scanner and some database queries. This was a perfect chance to use a Raspberry Pi to bridge that gap.
A traditional small PLC that would have cost many orders of magnitude more. Other customers have used an inexpensive Raspberry Pi to handle remote sensing of temperature readings or run InTouch HMI Machine Edition for data connectivity. All of these are good reasons to have a Raspberry Pi loaded and ready to go on standby for a simple and cheap business continuity solution.
What about you? Have you used any of these alternative solutions in your environments? Where do you feel they might be most applicable?
Brian Fenn is vice president of operations at Avanceon, a certified member of the Control System Integrators Association (CSIA). For more information about Avanceon, visit its profile on the Industrial Automation Exchange.