28:06 The pulsing is not because of the power supply, it's because you are using Pin1, which is reserved for serial comms along with Pin0. And that's why it's pulsing. Never use pin0 and Pin1 for anything else, unless you know you want to do that.

You can always look at the getter material - if it's nice and shiny, the vacuum is good. If it's white and corroded, the vacuum is gone. This applies for all vacuum-devices with a fired getter.

The reason why the screen was blinking (27m39) is because you are using the TX and RX lines of the arduino as output lines. It will work but evertytime you upload to the arduino or the arduino is trying to send data over the serial, you will see the screen blinking.

It wasn't quite obvious at first but it seems like the grid selects the column of characters, while each dot of the anode is driven separately. Early in the video it sounded like the grid was the only thing controlling the dots. The interface also reminds me of the HD44780. One of the lines probably selects between data and commands, and there might be a read/write pin as well.

VFD's have always been a favorite of mine, especially the VU meters in top end cassette decks. Back in the mid eighties I was just starting out with electronics, and I spent a week trying to get one of these to work, finally giving up due to lack of knowledge and support equipment (I was in my teens). Awesome video, keep up the great work !!

I've been watching your channel for a few years now (while attending school for comp E), and it's awesome to say that I finally understand the content in the videos.

This is a typical VDF found in things like Gas Pumps and Cash Registers (The external customer display on the pedestal). We have boxs of these types of displays that came from everything from calculators & cash registers to alarm panels and old retired ATMs. varying colors from traditional blue/green to amber/orange

Thank you for your videos, as an undergrad in EE I was wondering how some things were done but was not quite sure how to go about it. Your videos are making things I somewhat understood make much more sense.

Excellent video, I always enjoy seeing hacky DIY stuff on the EEVblog, rather than the usual mailbags and teardowns (not that there's anything wrong with those).

Dave's video on any subject is always master grade. Thanks.

Really enjoyed this video, Dave. Nice to hear the thought processes you used and listen to your explanations. Please keep doing videos like this. Very educational and entertaining!

VFD's are BEAUTIFUL displays. That crisp, plasma-like colour is truly a sight to behold!

This is an absolutely amazing video! I love getting an insight into your thought process. Excellent job!

Just found this while trying to repair an old vfd, this is priceless info, thanks Dave

Nicely done! I always find these videos interesting. I have nowhere near the electronics knowledge to do this kind of stuff, but I have enough to grasp the concepts in your explanations and I appreciate your enthusiastic approach.

So awesome to see you get this this to work. Had such a module for ages in a drawer from an old commercial scale with red light coming off it. Shame that I got rid of it because after seeing this I would have love to try and get it to work myself as well. Really enjoyed the video! Thanks!

I have a pair of large 2x20 character VFDs made by IEE. I've been wanting to build a "command module" controller for Kerbal Space Program. There are existing projects that provide both hardware input controls (buttons, switches, joystick axes, etc) and readouts (character displays, analog meters, graphic readouts... even an Apollo style "8-ball" Flight Director Attitude Indicator). All I can say, is that every command module ends up different. The creativity of each builder really shines, and display choice can make a CM controller really stand out! Anyway, I LOVE the enormous 11mm character height of my VFD modules, and the two I have would provide 4x20 in total characters! I also have several smaller VFDs that could be used to display other flight data. I have two retail display posts that have either 2x16 or a 2x20 VFDs I can salvage... I'd have to dig them out. I'd like to use linear panel meters for my fuel gauges, and I was gonna use 7 segment LEDs for most of my numeric readouts (I'm considering doing the altitude in nixies... can't afford to do ALL of it in Nixies though... Bummer :P ) The large 2x20 modules I have feature a 26 pin header that is attached right next to a 40 pin NEC chip as well. Promising. The power connector is 6 pin, 2 pins are clearly power, but there is also a third pin connected to a very thin trace. Unsure as to it's function, or why it's on the power connector. *UPDATE:* I emailed IEE, and they sent me the original datasheets for my VFD module! YES!!! No serial interface on mine, but VERY similar to the one here, possibly the same processor. It uses an NEC 40 pin DIP and a 12 MHz crystal, with an interface that features the same number of pins (but mine is already brought out to a header, rather than a card edge connector). Now that I have a solid application and datasheets, I kinda wish I had bought more of these! I only paid 20 bucks each for the pair I have! I'll post the link on the blog.

I really enjoyed this one. It was interesting in that it described how VFDs work AND it had a bit of a voyage of discovery. Great stuff Dave, thanks.

Fantastic video Dave! Reverse engineering old bits of kit like this is really interesting, I'd like to see more of this on your channel, keep it up!

Well done Dave, thanks for spending your time on this, keep up the good work.

Thanks for this Dave - I love VFDs reminds me of my youth as an electronics apprentice at GEC Traction. By the way, Babcock are a multi-faceted company... even building nuclear reactors for submarines.

Awesome! I could watch videos like this (reverse engineering hardware) for days. Thank u Dave, and please do more like this. I am your padawan and learned a lot from this one vid and your narrative!

New from EEVBlog Studios: the VFD Shield. Very cool to see this work in action.

I am very happy to have found this KZfaq channel. You are a genius. My respect and admiration. Very good video, very good job. Best regard.

Working these interfaces out is (often) pretty straightforward. Some of the older ones require supply voltages that are difficult, such as 22V@250mA for one of my IEE's, but by the late 1980's, they were pretty much 5V all the way. The ones I have worked with fall into two general camps: Those that are designed for systems going VFD from the get-go, and those to connect instead of a printer. The first type generally have command/data selection via either a separate latch or a select (low is data, high is command on the one I am looking at). The second type is `Centronics compatible', with commands embedded int he data stream. They may honor backspace, LF, CR, and a few other control chars, as well s other special. Worked with a display years ago that did Epson dot matrix compatible graphics that inerfaced this way.

For every idea I have or part I find there always a great eevblog video accompanying it it's great!

Thanks Dave , I had just posted on the forums trying to trouble shoot a VFD from Noritake and had one response so far to get me started on seeing if I can repair , and now you video comes up :) This should help with a couple steps in finding a fault in mine . I'm reversing without the engineer ;) John

I can't believe only one other person thought the Dr. Emmett Brown quote was worth a comment. Thank you for the smile along with the information. You are a genius.

The vfd explanation was very easy to understand. Thanks!

Pioneer's dual-channel 24 segment dB displays were among the most visually rewarding. It's no small part of the attraction of their classic "Silver, quarter-inch, milled aluminum faceplate" dreadnought weight division Tape Decks like the RT-909 and the CT-F1250. As the years went by the resolution dropped, the number of segments plummeted and what was once a great thing, got cheapened to the point of the slower responding, overshoot prone physical "needle meters" once again prevailing, also owing to improvements in execution/design. (At least in neo-vintage gear.) But nothing reproduces the look of those great Flouroscan (their trade name) displays.

Awesome! My dad's vending machines have tons of these, I could not find out for the life of me how to operate one. Now I can update the machine circuits without buying all new displays :)

Fantastic! Thanks for taking the time to do this!

This is the type of video i look forward to Dave. Second to teardown tuesday

One of the better videos in a while - I for one much prefer the videos were you are actually DOING something to things like the mail bag. Also, more Fundamental Fridays, please!!!!!!!!!!

Fair play Dave, you're a treasure trove of brilliant info.

This video is my favorite EEVBlog. Love it!!

I think the pulsing is due to the serial UART on pins 0 and 1 (one's Rx and one's Tx). The Arduino software includes bootloader on the ATMega (which is usually pre-flashed on complete boards) which allows it to be programmed over the UART (the USB is simply an FTDI serial port on those pins, with a reset on serial connection). When the board resets the bootloader waits a while for UART data before proceeding to the program so uploading and verifying ends up toggling the serial (it also flashes what's an LED on pin 13 most boards to show the bootloader's starting (happens irrespective of whether you're uploading anything).

These were my favorite display's back in the day. All my older amateur radio gear used VFD's but years back everything went LCD because it was far cheaper and used way less power.

I have one of these lay around, out of some old, broken HP measurement device I got a few months ago. I was thinking of throwing it away due to lack of storage space, but now you inspired me to hack it, and see if it still works. Let's see what I can get :) Greetings from Germany!

More videos like this please. Truly enjoyed it.

Dave, thank you so much. I've been learning a lot from you. This one is very cool. I was planning to make a vu-meter using vfd and this inspired me a lot :)

WTF Dave. I literally only just bought a VFD a couple days ago and been fumbling trying to get a pinout having never used a VFD display before... then you bring this video out. It's like you're physic

Loving the vacuum leaking out comment really had me in stitches :D

One of your best videos, Dave! Couldn't find any bigger thumb than the default though. ;-) Thanks a lot!

Really good work there Dave! Watching your videos make wanna blow-off the dust from my E.E. degree. Too bad I am in another business and got very little time to do that =(. Keep up the good work mate, I really enjoy your videos. Greetings from Greece!

Asked for it and got it. Thank you very much Dave. :)

man that was great fun! more videos like this :) getting into old electronics like this is so coool

Great explanation. I would love to have one of those for some of my projects. Super-cool! Thanks.

How does Dave know Bob is my Uncle! It's like he makes me aware of it every video I watch!

I'm going to quibble with the control description around minute 6! The grid typically covers many anodes in a VFD (at least the old Soviet VFDs like the IV-22). You supply anodes individually to light them up (typically through a high-side driver IC), and can control the brightness of the entire display (a single 7-segment cell in the case of IV-22) by varying the grid voltage.

My digital clock broke recently so I’ve been researching clocks and it occurred to me I could make my own with an Arduino and a display, so now I’m researching VFDs since I love the look. I might try to salvage one from some broken AV equipment if I can any on eBay or any dumpsters near me, good ol’ reusing and recycling right!

Oh wow awesome timing, I just got several of these but much larger, and one big one that says plasma on the back but looks like a VFD.

Awesome video, as usual!!! Congrats!!! I really hope you continue doing stuffs like these!!! Thanks!

The construction of VF devices allows them to be used as a single vacuum triode capable of amplification at up to 100kHz or so. Good for a novel audio preamplifier stage with a mellow 1940s sounding output.

A wonderful piece of hardware. Beautiful.

17:44 I particularly liked Dave doing the "Duanggggg ...".

Awesome Dave, totally cool. Learned a bit there. Thanks

I love VFD; great video as always Dave :)

I've paused and counted: it's 40x2

omg i am a display obsessed one, especially vfd's, this is very satisfying thx

Awesome video, Dave. I managed to salvage one of those types of displays from an old shop till. So I'll definitely be putting your theory to the test on mine :)

Great video ! I got really excited when the test characters popped up ! LoL. Cheers!

"vacuum leaked out" :D:D

These things have their own character table, best check if there is a datasheet to show the table or else mod a new chip in place of the controller with a new character lookup table to suit your needs. The nice thing about this vfd is that it is early design which allows every bit of it to be highly modular. Wish all technology today is like that.

Finally some actual electronics :-) well done ...

"if the vacuum leaked out" good one Dave. We know what you meant :D

That was just a lot of fun. Really enjoy your stream of consciousness reverse engineering videos. It's good for the newcomers too since it shows the dead ends, the oops, etc. The other canned videos where everything goes perfectly can be frustrating for beginners because they think they are doing something wrong. Nice vid Dave

Fantastic, thanks Dave! I really enjoyed that.

Love the way by the text appears on display!

Great video - I salvaged a VFD from a late 70's battery arcade game - gonna hook it up!

Fascinating!!!!! I watched, enthralled, mesmerised, honestly. I saw VFD's coming in (slowly) in the early 80's then they became the norm for a while, included on HiFi equipment, etc. VFD's were beautiful, largely due to the color but also the unknown, mysterious, they were like magic; now I am old, they have NOT lost their beauty and charm. When I watched your video, it was like watching a magic trick being explained, but, due to the way my brain works, you have added to the wonder :-) Well done and thank you All the best Jay (South Wales)

nice! I love the reuse / hack / repair / re-purpose stuff.

And this is how we do it. I would have done it just the same way with my adurino attached....:) Thanx for this one Dave.

Great video!

Love these videos Dave

Nice video! Thanks Dave.

Loved the back to the future reference.

This is so cool! I love these videos so much.

Nice one Dave, I love VFD's, They were great in early Casio calculators. This video is going to very useful. They look so much cooler than LCD's and have advantages in dark rooms that LCD's fail at. It's a pity they draw so much current huh?

Really cool display :) Nicely done!

Yeah that was a good one !!! Love how easy you got it up and running... It would have take me forever I guess ...

Nice! A have an old vacuum fluorescent display, I'll try to make it work. Thanks for the well explained video, Thumbs up! :)

I've never had the opportunity to play with one of theses, so i really enjoyed this video. As for it not being ASCII, well it could be some variant of extended ASCII. The easiest way would be to map out the characters in the form of a loop. Start with 32 (SPACE) and end with 255. 32 through 127 are the printable ASCII characters, and 127 - 255 are the 'extended'. I'd also like to see if one of the first 31 characters generates a clear screen.

Absolutely love it Dave. Awesome job, I would have done it pretty much the same way as you. Thanks for sharing I always learn something from you. Best Wishes n Blessings. Keith

Thats great, you have a lot of knowledge, i impressed.

Thank you very much dude...aint watched one of your vids in ages 😃, time well spent!

Learnt so much. Thanks for the video.

That was a really nice logical approach to gain some understanding of a bit of unknown gear and in making it useful again. I enjoy seeing this kind of recycling of electronics. I myself like the VFD's, IMHO, LCD's seems cheap and nasty by comparison to such an elegant bit of engineering as a VFD.

I fix pinball machines for a living and this appeals to me a lot. Gottlieb Pinballs used green VFDs similar to this one, which reminds me of the first Sys 80B. displays. Also, Babcock used to manufacture orange 128 x 32 DMDs for newer generation pinballs in the 90s.

Impressive, thanks for sharing!

nice one, Dave

Fantastic video.

i love vfd's and i use them whenever i can

More videos like this, Dave. Excellent!

Awesome video, as usual. I wonder why those digital scopes are not floating ground. It would be so handy at times, just like when using a multimeter.

Nice Back to the Future III reference thrown in there, Dave. :D

I would say that display was designed to be interfaced with an 8051/6805 parallel system bus. So, the line your toggling is probably the R/W line. But there is either a command/data line, Or... you can try rotating through all the non-ASCII bytes, some are likely to be control codes. Such as brightness, CLS, char position, etc.. Some displays even use an Escape code. So you would send the Escape char, and then the control code.

Awesome video!

I love the look of vfds. back when I had one it had a simple serial interface

Am I the only one who read UFO's instead of VFD's up there in the corner of the whiteboard? =) Anyway, awesome and interesting video as usual Dave, very much appreciate it !