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Benson Hougland

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How to Build a Raspberry Pi with Node-RED and Industrial GPIO

Posted by Benson Hougland on Dec 14, 2016 3:39:17 PM

UPDATE: This post has been updated to reflect changes in the most recent Raspbian Jessie Lite image (no longer includes Node-RED or node.js) and to use the new Digital I/O for Raspberry Pi Starter Kit for I/O hardware (new code, photos, and video).

The Raspberry Pi® is an unquestionably powerful computer for just $35. And it really is just that: a computer. That means the Pi is capable of many tasks and perfect for many automation applications.

Couple the Pi to industrial, solid-state digital inputs and outputs, and you can build compelling and cost-effective solutions for commercial and industrial applications, too.

One of the easiest and fun ways to quickly build software applications is with Node-RED, the free, open-source software tool designed by IBM Emerging Technologies and used for wiring together hardware devices, APIs, and online services in new and interesting ways.

However, Node-RED is only included in the full PIXEL GUI version of the Raspbian Jessie Operating System, available from raspberrypi.org. Their latest 2017-07-05-raspbian-jessie-lite.img build for headless operation (no monitor, keyboard, or mouse required) is no longer bundled with either Node-RED or the required software tools node.js and npm.

The purpose of this post is to guide you through creating a headless Raspberry Pi computer with the latest versions of Node-RED, node.js, and npm, building a Node-RED application, and controlling and sensing GPIO connected to industrial digital I/O, quickly and simply. (For a sneak peek at the result of this build, see the video near the end of this post.)

Image: New Opto 22 Digital I/O for Raspberry Pi Starter Kit with Raspberry Pi 3 Computer

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Topics: Node-RED, GPIO, G4 I/O, Raspberry Pi, Digital I/O for Raspberry Pi

How I upgraded my SNAP PAC controllers to version 9.5 and the RESTful interface

Posted by Benson Hougland on Aug 3, 2016 12:00:16 PM

I'm extremely excited about the new capabilities of the 9.5 firmware and, in particular, the new RESTful interface (REST API and HTTP/S server) for SNAP PAC controllers. I have several PACs throughout my home for various tasks like lighting, A/C, irrigation, energy management, monitoring, and surveillance. The new RESTful interface allows me to take my home automation system to completely new levels, including interacting with my other home automation/IoT products, like my Nest thermostats, smoke alarms, and NestCams; my Philips Hue lighting; my Wemo switches; and much more.

This post isn’t about home automation, however. It’s about getting the firmware upgrade done and configuring the HTTP/S RESTful server. And in doing so, it was important to me (and my application) that I preserved the persistent control system variables used in my control strategies. So...the following are the steps I took to upgrade my firmware while preserving important data and getting started with REST.

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Topics: PACs, Firmware, PAC Control, API, REST API, RESTful server, PAC Manager, OptoTagPreserve, REST

Introducing groov

Posted by Benson Hougland on Jan 24, 2013 12:33:00 AM

Change the way you think about HMIs. Forever.

Now you've got groov—a totally new way to develop and distribute operator interfaces for your machine, plant, or facility.

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Topics: groov

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