A common sight on factory floors, stack lights are used to indicate the status of machinery to anyone within visual range. But hackers have found out you can pick them up fairly cheap online, so we’ve started to see them used as indicators in slightly more mundane situations than they were originally intended for. [Tyler Ward] recently decided he wanted his build own network controlled stack light, and thought it would double as a great opportunity to dive into the world of Power Over Ethernet (PoE).
Now the easy way to do this would be to take the Raspberry Pi, attach the official PoE Hat to it, and toss it into a nice enclosure. Write some code that toggles the GPIO pins attached to the LEDs in the stack light, and call it a day. Would be done in an afternoon and you could be showing it off on Reddit by dinner time. But that’s not exactly what [Tyler] had in mind.
On the software side [Tyler] has developed a firmware for the ESP32 that supports both Art-Net and RDM protocols, which are subsets of the larger DMX protocol. That means the controller should be compatible with existing software designed for controlling theatrical lighting systems. If you’d rather take a more direct approach, the firmware also sports a web interface and simple HTTP API to provide some additional flexibility.
When most people want to keep tabs on what their 3D printer is up to while they’re out and about, they’ll install OctoPrint on a Pi and be done with it. But what if you’re just on the other side of the room? Inspired by the stack lights used on factory floors, [Jeff Glass] decided to add a similar system to his Prusa Mini so he could see what it’s up to at a glance.
It turns out you can get these lights pretty cheaply online from the usual retailers, and as [Jeff] explains in the video after the break, driving them is about as easy as it gets. Rather than being some kind of addressable device, they generally have a single common 12 or 24 volt DC wire and ground lines for each color. With a USB controlled relay board, kicking on the appropriate light is simple from your operating system of choice.
What ended up being a bit harder was finding out what the Prusa Mini was up to. The printer offers up a simple status web page, but it has a few oddball quirks that make it difficult to scrape; such as presenting a little pop-up message that you have to manually close each time you load the page. But after spending some time with the powerful Selenium library for Python, he was able to create a script that worked its way through the UI and pulled the relevant status messages. Obviously the resulting code is Prusa specific, but the general concept would work on other printers assuming you can find a reliable way to pull the device’s current status.
After coming up with a wall mounted enclosure for the electronics that doubles as a mount for the light itself, [Jeff] can now see if his printer needs attention from clear across the room. An especially nice feature when the printer is all buttoned up inside of its enclosure.
When working on software development in a team environment, it’s important to know the status of your build at all times. Jenkins can display build automation info on a screen but where’s the fun in that? A popular office project is to build some kind of visual display of a project’s status, and [dkt01] has done just that with this stack light build monitor.
In this day and age of online shopping, random bits of industrial hardware are just an eBay away, so it’s easy to find some cool lamps or indicators for any project. [dkt01] sourced a standard 24V stack light off the shelf. With its green, red, and yellow indicators, its perfect for showing the current status of their build server.
The project uses an Arduino Pro Micro combined with an ENC28J60 Ethernet adapter. We used to see that chip all the time but in 2017 it’s somewhat of a classic setup with the great unwashed masses largely migrating to the ESP8266. However, for the purposes of this project, it was perfect for connecting to the wired office network (after all, you want to know the status of your build and not of your WiFi). [dkt01] even managed to get a web configuration to work despite the relatively meager resources of the ATmega32u4.
The build is cleanly executed, with the microcontroller and Ethernet hardware tucked into a 3D printed base for the stack light’s enclosure. It’s far more likely to become a permanent office fixture if it’s a tidy build without wires hanging out everywhere so a custom PCB ties everything together neatly. In another nice touch, the stack lights flash on initialization to indicate if the DHCP lease was successful, which makes troubleshooting easier. There’s an overview of all different light combinations and meanings in the video after the break.