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Jean-Luc.Suchail
Agreed. There is however an easy way to blank the nixie: send an invalid Hex ...
David Ashton
1 whole MCU plus 10 transistors to drive a Nixie? There's a 40-year old chip ...
DIY Goes Back to Future with Nixies at DESIGN East
Clive Maxfield
9/13/2012 7:59 PM EDT
BOSTON -- LEDs and other display devices are all very nice, but there's something unique about Nixie Tubes that is guaranteed to capture the attention of most any engineer and make more than a few of them "Oooh" and "Ahhh"!
At next week's DESIGN East conference (Sept. 17-20, #designeast) at Boston’s Hynes Convention Center, the ever-popular Gadget Freak column from Design News will be presenting a live show called “Gadget Freak DIY.”
[ Don't miss DESIGN East, Sept 17-20 in Boston. Embedded, Android, MEMS, and more. Click here to register and get a 15% DISCOUNT ON ALL-ACCESS AND SUMMIT PASSES or a FREE EXPO PASS.]
Gadget Freak DIY is dedicated to presenting do-it-yourself projects to the design community. The presentations on Sept. 19 will provide an opportunity for innovators to describe how devices were conceived and implemented and, most importantly, to show them off to fellow engineers.
Sponsored by Allied Electronics, the Gadget Freak DIY session will kick off at 3 p.m. at the DESIGN East Theater (there will be some giveaways for lucky participants). The presenters each have five minutes to wow the audience with their projects.
This year's collection of do-it-yourself designs includes everything from cyberpunk helmets with LED visor illumination and chromium accents (I want one!) to a cloud-based remote control system that allows the operator to guide a ping pong ball from anywhere in the world.
The project that really has us jazzed is the Nixie Tube Clock, created by John Day and Sean Cappy of Microchip. The project’s design and implementation provides so much instructional value that Day and Cappy have been invited to give an in-depth presentation at 1 p.m. on Sept. 19.
Behold, Nixie Tubes!
This project employs a tri-colored LED mounted under each Nixie Tube. The LEDs can be
individually controlled to display any color, can transition from color to color and augment the main display with a variety of effects to complement whatever data is being presented.
The clock also contains an integrated temperature sensor. The display alternates between time and temperature. It also renders a 1-second random sequence every time it transitions between the time and temperature.
The Microchip presentation will also discuss various design considerations, tool use and implementation details. The clock can be programmed using a TV remote controller while an integrated PIR motion detector activates the display when someone enters the room and then powers down the Nixie Tubes when the room is empty.
Forty-four I/O pins drive the tube cathodes, including 12 for the PWMs driving the LEDs. If a single microprocessor was used, a 100-pin device would be needed. The DIY solution was to assign a separate PIC16F1509 microcontroller to manage each tube, then use a master PIC16F1825 microcontroller to control the entire system, with everything being linked by an I2C bus.
The Nixie Tube design.
Next: Keep it simple
At next week's DESIGN East conference (Sept. 17-20, #designeast) at Boston’s Hynes Convention Center, the ever-popular Gadget Freak column from Design News will be presenting a live show called “Gadget Freak DIY.”
[ Don't miss DESIGN East, Sept 17-20 in Boston. Embedded, Android, MEMS, and more. Click here to register and get a 15% DISCOUNT ON ALL-ACCESS AND SUMMIT PASSES or a FREE EXPO PASS.]
Gadget Freak DIY is dedicated to presenting do-it-yourself projects to the design community. The presentations on Sept. 19 will provide an opportunity for innovators to describe how devices were conceived and implemented and, most importantly, to show them off to fellow engineers.
Sponsored by Allied Electronics, the Gadget Freak DIY session will kick off at 3 p.m. at the DESIGN East Theater (there will be some giveaways for lucky participants). The presenters each have five minutes to wow the audience with their projects.
This year's collection of do-it-yourself designs includes everything from cyberpunk helmets with LED visor illumination and chromium accents (I want one!) to a cloud-based remote control system that allows the operator to guide a ping pong ball from anywhere in the world.
The project that really has us jazzed is the Nixie Tube Clock, created by John Day and Sean Cappy of Microchip. The project’s design and implementation provides so much instructional value that Day and Cappy have been invited to give an in-depth presentation at 1 p.m. on Sept. 19.
Behold, Nixie Tubes!
This project employs a tri-colored LED mounted under each Nixie Tube. The LEDs can be
individually controlled to display any color, can transition from color to color and augment the main display with a variety of effects to complement whatever data is being presented.
The clock also contains an integrated temperature sensor. The display alternates between time and temperature. It also renders a 1-second random sequence every time it transitions between the time and temperature.
The Microchip presentation will also discuss various design considerations, tool use and implementation details. The clock can be programmed using a TV remote controller while an integrated PIR motion detector activates the display when someone enters the room and then powers down the Nixie Tubes when the room is empty.
Forty-four I/O pins drive the tube cathodes, including 12 for the PWMs driving the LEDs. If a single microprocessor was used, a 100-pin device would be needed. The DIY solution was to assign a separate PIC16F1509 microcontroller to manage each tube, then use a master PIC16F1825 microcontroller to control the entire system, with everything being linked by an I2C bus.
The Nixie Tube design.
Next: Keep it simple
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UncleRemus
9/14/2012 12:42 PM EDT
$5.00 for a circuitboard from ValueProto?
I don't think so.
This must be wrong, I punch in a 2"x2" board and they quote 37 dollars.
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UncleRemus
9/14/2012 12:48 PM EDT
Maybe they got the "mention us in EEtimes" discount for those $5.00 circuitboards.
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Max the Magnificent
9/14/2012 2:11 PM EDT
@UncleRemus: Sorry -- this was my bad -- I was interviewing John over the phone -- he said "$25" but I heard "$5" and that's what I wrote down.
I just touched base with John again, he says that the price was $25 each for a 1.5" x 4", quantity = 4, and a 2-week turnaround time.
But still and all, I think $25 for a hobbyist prototype board of this level of sophistication is a REALLY good deal. I don;t want to think what I've ended up paying other board vendors in the past...
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Max the Magnificent
9/14/2012 2:13 PM EDT
PS For others just coming in, my article originally said $5 a board for the prototype (unpopulated) PCBs -- I made a mistake -- it should be $25 -- and I just made that change in the article -- so UncleRemus wasn't imagining things (grin)
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ReneCardenas
9/14/2012 5:33 PM EDT
Awesome project, very niffty application, even at $25 each board that is a great value, as youo pointed it out Max.
I have to confess to been also a fan of Eagle, for their powerful and user programmable scripts. I was able to place 25 items (SOP6 LEDs)with perfect spacing in a square array 5x5.
So Excel is a handy tool but Eagle scripts could have been as well suited for that job.
Thanks for sharing, wish I could make it, but work and other obligations would make it hard for me. Max, hope you can give us a photo gallery of the event.
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Max the Magnificent
9/17/2012 10:41 AM EDT
Hi Rene -- sad to relate I'm in the same boat as you -- too much to do -- so I won't be attending -- but I know some folks who are there (it starts today)
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John Pote
9/17/2012 7:00 PM EDT
WOW Nixie tube nostalgia! First desk calculator I saw, early 70s' in school, used them. LEDs and VF displays that followed just didn't convey the same quality. Curious how the circuit design is a 21st century solution to a 20th century problem, 1 MPU per Nixie. Luxury! Back then 1 MPU/CPU was all we were allowed but we could have a few of octal latches and lots of driver code to multiplex them. How well I remember filling a 2k byte eprom with intricately interwoven monolithic assembler. I still wind up colleagues by threatening to put a 'goto' in my 'C'. They fall for it every time.
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Compotek_LB
9/18/2012 4:03 AM EDT
Nice application and at the first look I agree to John Pote: One uC per Nixie seems really a luxury. - The Nixies could also be controlled by some latched shift registers. So you use just one uC port pin for shifting and a second one for latching. But then you will need a uC that has some more PWM outputs for the independent RGB LEDs.
So all in all the 4 uC solution is really a 21st century solution. uC are that cheap and breaking up a big problem in parts resulting in more, but smaller problems (thinking of hardware and software) is a very good way to solve engineering problems - IMHO the century doesn't matter in this case... :-)
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Chris.Barron
9/19/2012 3:33 AM EDT
I don't see what is so revolutionary about this clock. I first put one uC per tube into my Microchip based B7971 nixie tube 'Smartsockets', back in 2006. I've since made several versionjs for different display types. I was also the first person to put coloured LED's behind nixie tubes. There's a lot about this clock which is familiar to me....I keep my project up to date and I've recently finished VFD display based smartsockets.
http://groups.yahoo.com/group/smartsockets/
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Chris.Barron
9/19/2012 3:36 AM EDT
...I also put a video on Youtube of my Microchip based smartsockets driving different display types, here
http://www.youtube.com/watch?v=ek8S4r7bBUU
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David.Jones_#2
9/19/2012 3:21 PM EDT
Is this project publishing your board and code and other design/implementation files? Looks like a great DIY project.
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Duane Benson
9/23/2012 5:04 PM EDT
One of the aspects of this presentation that I really enjoyed was the walk through of their thought process when making design decisions. i.e. what MCU and how many, how to program, and things of that sort.
All in all they did an excellent job with this.
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David Ashton
9/23/2012 10:22 PM EDT
1 whole MCU plus 10 transistors to drive a Nixie? There's a 40-year old chip called a 74141 that does that (and you can still get them....)
Yeah, yeah, they draw more current, and you can't easily blank them..... but were I doing this I'd use them, and just remove power to the whole display chain if it was not required. But then I always have been a bit of a luddite.....
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Jean-Luc.Suchail
10/4/2012 9:23 AM EDT
Agreed. There is however an easy way to blank the nixie: send an invalid Hex code like 1111, (or any 11xx), the 74141 disables all outputs.
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