Reddit user [InThePartsBin] found some VFDs (Vacuum Fluorescent Displays) on an old PCB on eBay. The Russian boards date from 1987 and have a bunch of through-hole resistors, transistors and a some mystery ICs, plastic wraps around the legs and the top of the tube is held steady by a rubber grommet (the tip itself goes through a hole in a board mounted perpendicular to the main board.) Being the curious kind of person we like, and seeing the boards weren’t too expensive, he bought some in order to play around with to see if he could bring them back to life.
After getting the VFDs lighting up and figuring out the circuitry on the back, [InThePartsBin] decided that a clock was the best thing to build out of it. It was decided that a specialized VFD driver chip was the easiest way to make the thing work, so a MAX6934 was ordered. To give the clock some brains, an ATmega328 was recruited and to keep time, [InThePartsBin] had some DS3231 real-time clock modules left over from a previous project, so they were recruited as well. A daughterboard was designed to sit on the back of the vintage board and hold the ‘328 and the VFD driver chip.
Once [InThePartsBin] soldered on the components it was time to fire it up and send 1’s to the driver to turn on all the segments on all the tubes. Success! The only thing that [InThePartsBin] has left to do is write the code for the clock, but all the segments and tubes are controllable now, so the hardware part is done. There are other VFD clock projects on the site: Check out this one, or this one, and bask in the beautiful steel-blue glow.
Not just another steampunk fashion statement, [Johngineer’s] ChronodeVFD wristwatch is as intricate as it is beautiful. Sure, we’ve seen our share of VFD builds (and if you want a crash course in vacuum fluorescent displays, check out Fran’s video from earlier this year) but we seldom see them as portable timepieces, much less ones this striking.
The ChronodeVFD uses a IVL2-7/5 display tube, which in addition to being small and low-current is also flat rather than rounded, and features a transparent backing. [Johngineer] made a custom board based around an AtMega88 and a Maxim DS3231 RTC (real time clock): the latter he admits is a bit expensive, but no one complains about left-overs that simplify your design.
The VFD runs off a Maxim MAX6920 12-bit shift register and is powered by a single alkaline AA battery. A rechargable NiMH would have been preferable, but the lower nominal voltage meant lower efficiency for his boost converters and less current for the VFD. [Johngineer] won’t get much more than 6-10 hours of life, but ultimately the ChronodeVFD is a costume piece not meant for daily wear. Swing by his blog for a number of high-res photos and further details on how he built the brass tubing “roll cage” enclosure as well as the mounts for the leather strap.
Sometimes the stars align and we get two somewhat similar builds hitting the Hackaday tip line at the same time. Recently, the build of note was clocks using some sort of display tube, so here we go.
First up is [Pyrofer]’s VFD network time clock (pic, above). The build started as a vacuum flourescent display tube he salvaged from an old fruit machine – whatever that is. The VFD was a 16 character, 14 segment display, all controlled via serial input.
The main control board is, of course, an Arduino with a WizNet 5100 Ethernet board. The clock connects to the Internet via DHCP so there’s no need to set an IP address. Once connected, the clock sets itself via network time and displays the current date, time, and temperature provided by a Dallas 1-wire temperature probe.
Next up is [Andrew]’s beautiful Nixie clock with enough LEDs to satiate the desires of even the most discerning technophile. The board is based on a PIC microcontroller with two switching power supplies – one for the 170VDC for the Nixies, and 5V for the rest of the board.
A battery backed DS1307 is the real-time clock for this board, and two MCP23017 I/O expanders are used to run the old-school Nixie drivers
All this is pretty standard for a Nixie clock build, if a little excessive. It wasn’t enough for [Andrew], though: he used the USB support on his PIC to throw a USB port on his board and wrote an awesome bit of software for his PC to set the time, upload new firmware, and set the color fade and speed. With this many LEDs, it’s not something you want in your bedroom with all the lights on full blast, so he implemented a ‘sleep’ mode to turn off most of the lights and all the Nixie tubes. It’s a great piece of work that could easily be successfully funded on Kickstarter.