For those of us old enough to remember the VCR (and the difficulty of programming one), the ubiquitous vacuum fluorescent display, or VFD, is burned into our memories, mostly because of their brightness and contrast when compared to the superficially-similar LCD. These displays are incredibly common even apart from VCRs, though, and it’s easy to find them for next to no cost, but figuring out how to drive one if you just pulled it out of a 30-year-old VCR is going to take some effort. In this build, [mircemk] shows us how he drives unknown VFD displays using an Arduino in order to build his own weather forecasting station.
For this demonstration [mircemk] decided to turn a VFD into a weather forecasting station. First of all, though, he had to get the VFD up and running. For this unit, which came from a point-of-sale (POS) terminal, simply connecting power to the device turned on a demo mode for the display which let him know some information about it. From there, and with the knowledge that most POS terminals use RS232 to communicate, he was able to zero in on the Rx and Tx pins on the on-board microcontroller and interface them with an Arduino. From there it’s a short step to being able to output whatever he wanted to this display.
For this project, [mircemk] wanted the display to output information about weather, but rather than simply pull data from some weather API he is actually using a sensor suite connected to the Arduino to measure things like barometric pressure in order to make a 12-hour forecast. The design is inspired by old Zambretti weather forecasters which used analog wheels to input local weather data. It’s an interesting build not only for the VFD implementation but also for attempting to forecast the weather directly with just a tiny sensor set instead of downloading a forecast to display. To do any better with your own forecasts, you’d likely need your own weather station.
When you have a small stock of vacuum fluorescent displays (VFDs) straight out of the 1976 Radio Shack catalog, you might sit around wondering what to do with them. When [stepawayfromthegirls] found out that his stash of seven DT-1704A tubes may be the last in existence, there was no question. They must be displayed! [stepawayfromthegirls]’ mode of display is this captivating clock build. Four VFDs with their aqua colored elements are set against a black background in a bespoke wooden case. Looking under the hood, the beauty only increases.
Keeping the build organized was not an easy task because the tubes are designed in such a way that each segment must be individually controlled. The needed I/O duties are provided by an Arduino Mega 2560 Pro (Embed). 28 2n3904’s each with their two resistors serve as drivers for each VFD segment.
The output of a 24 V AC transformer left over from the 1980s is rectified to 34 V of DC power which is then regulated to 27 V to power the tubes. Switching power supplies provide 6 V to the Arduino and 1.3 V to the filaments. If you look closely, you’ll also see a GPS module so that the clock doesn’t need to be set. To future-proof the clock against daylight savings time adjustments, a potentiometer on the back of the case allows the user to set custom hour offsets without editing any code.
We think the end result is a remarkably clean, simple, and elegant clock that he will be proud of for many years to come!
A lot of electronics wind up in landfills, and when [Playful Electronics] saw an old cash register heading for the dump, he decided to give its VFD display a new life as an Arduino peripheral. While you might not find the exact same parts, it is still fun to watch him work through the process, and you might find some tips for doing your own upcycle project next time you see some old tech heading out to pasture.
The project was relatively straightforward since data for the display was available. It is meant to connect via RS232 with a point of sale printer, so working with it is pretty straightforward.
In terms of ease of integration and density of the information that can be shown, it’s hard to argue with the fact that modern displays like LCD panels are anything but superior to the character-based displays of yore. Throw one into a project, add a little code from a few off-the-shelf libraries to drive it, and you’re on to the next job.
Efficient, yes, but what does this approach do for the engineer’s soul? What design itch does it scratch; what aesthetic does it celebrate? Nostalgic questions, true, and not every project lends itself to exploring old display technologies. But some still do, thankfully, and when the occasion calls for it, we’re glad that there are those out there who are still actively involved in the retro display community, making sure that what was once state-of-the-art technology is still able to be added to modern projects.
There’s no doubt that Fran Blanche is one of those passing the torch of vintage displays down to the next generation. You’ll certainly know Fran from her popular Fran Lab channel on YouTube, where in addition to about a million other interests, she has explored some really cool vintage displays: the Nimo cathode-ray tube, super-bright incandescent seven-segment displays, the delightfully strange “Bina-View”, and many, many more. Fran will stop by the Hack Chat to talk about all these retro displays, what she’s learned from collecting them, and how they shaped the displays we take so much for granted these days. Oh, and perhaps we’ll also talk about her upcoming ride on “G-Force 1” as well.
The elegance of Power over Ethernet (PoE) is that you can provide network connectivity and power over a single cable. Unfortunately not nearly enough hardware seems to support this capability, forcing intrepid hackers to take matters into their own hands. The latest in this line of single-cable creations is this beautiful Vacuum Fluorescent Display (VFD) clock from [Glen Akins].
One of the key advantages VFDs have over their Nixie predecessors is greatly reduced energy consumption, and after [Glen] ran the numbers, he saw that a display using six VFD tubes could easily be powered with standard PoE hardware. With this information, he started designing the PCB around the early 1990s era IV-12 tube, which has the advantage of being socketed so he could easily remove them later if necessary.
[Glen] first had to create a schematic and PCB footprint for the IV-12 tube that he could import into Eagle, which he was kind enough to share should anyone else be working with these particular tubes down the line. After a test of the newly designed socket was successful, he moved onto the rest of the electronics.
The clock is powered by a Microchip PIC18F67J60, which connects to the Ethernet network and pulls the current time down from NTP. After seeing so many clocks use an ESP to connect to the Internet over WiFi, there’s something refreshing about seeing a wired version. The tube segments are driven by a HV5812, also Microchip branded. Lastly, [Glen] used a number of DC/DC converters to generate the 1.5 V, 3.3 V, 5 V, and 25 V necessary to drive all the electronics and VFDs.
As [sjm4306] says, “You can never have too many clocks based on obsolete display technologies.” We couldn’t agree more, and this single-tube VFD clock is one we haven’t seen before.
The vacuum-fluorescent display that [sjm4306] chose to base this clock on is the IV-21, an eight-digit seven-segment display on the smallish side. The tube is Russian surplus from the ’80s, as all such displays seem to be. The main PCB sports an ATMega328, a boost converter to provide the high voltage needed to run the VFD, a real-time clock, and the driver chip for the tube segments. The tube itself lives on a clever riser card that elevates the display above the main PCB and puts it at the proper angle for reading. [sjm4306] designed it to be modular; should you want to user a bigger VFD you need only make a new riser PCB. Figuring out the proper way to space the through-holes in Eagle proved elusive, but he hacked a solution using a spreadsheet to handle the trigonometry and spit out Cartesian coordinates for each hole. Pretty neat. The video below shows the clock assembly and a test.
The clock employs an IV-27M vacuum fluorescent display, manufactured in the now-defunct USSR. Featuring 13 seven-segment digits, it’s got that charming blue glow that you just don’t get with other technologies. A MAX6921AWI chip is used to drive the VFD, and an Arduino Mega is the brains of the operation. There’s also an HD44780-compliant LCD that can display further alphanumeric information, and a 4×4 keypad for controlling the device.
The best part of the build though is the enclosure. The VFD is encased in a glass tube, and supported at either end by 90-degree copper pipe couplers. These hold the VFD aloft, and also act as a conduit for the wires coming off each end of the tube. It’s all built on top of a wooden base that holds the rest of the electronics.