# WORKSHOP VIDEO #40: Nixie tube and logic analyzer demo for Maker Faire

in Videos by | 19 comments

We’re getting ready for the Global Geek Tour of New York. For those of you who can’t join us at the World Maker Faire, here’s a quick logic analyzer demo using a single block of the Magnificent Nixie Thing we’re tinkering with.

Each nixie module has 2 tubes and control circuitry based on new old stock Soviet driver chips. Two nixie drivers are connected to a 74HCT595 serial to parallel output chip. The setup is driven via a simple Arduino sketch that increments the numbers shown on the tubes.

A logic analyzer is a miraculous debugging tool that records invisible electrical signals and shows them on a screen. This is a life saver when you can’t figure out why a circuit isn’t working.

In this case we tap the Logic Sniffer into the wires between the Arduino and the nixie module. It records the signals and displays them as a graph on the computer screen.

The signal here decodes to 01000100. Given the schematic and info from last week, can you tell what digit lights with that value?

No workshop video next week, but the following week look for a new style of geek video from the New York trip. It’s evolving.

You can get the ATX Breakout Board for \$14, and the Logic Sniffer for \$50 at Seeed Studio.

If you want to know more about the project design, check out our previous video about it.

If’ you’re going to Maker Faire check out our tips and behind the scenes video from Bay Area Maker Faire. And don’t forget your tablecloth!

This entry was posted in Videos and tagged .

1. Ernie says:

01000100 = 66

2. Ernie says:

correction 44

3. Ernie says:

BCD 0-9 only
both nixies receiving the same out put.
8421 8421
0100 0100
——- ——-
4 4

4. ginpb says:

44, but Ernie was faster.

5. James Bowes says:

4, Since I believe he was just asking for the value on a single Nixie.

6. tayken says:

Still no 42! :(

7. Alecs says:

Or is it 2 (22)

8. Electroalek says:

68

9. Hans de Jong says:

I was hoping the schematic would show the BCD code and nixie segments not 1:1 addressed, but no :(

Anyway, the digits are 4 on tube 1 and 4 on tube 2.

• Hans de Jong says:

Oops I mean 22, because the data is shifted in LSB to MSB, meaning the nibble needs to interpreted reversed.

• ginpb says:

that could be a good point

10. voidptr says:

BCD 4 4
it is shifting MSB first , the line go into 595 DS, enter latch 0 and moving toward latch 7
i guess you can also shift more for more nixie module .

here a question, is nixie will work on 110v AC corrected-filtered to 110 DC ? or it need really more voltage ?
:-)

• Ian says:

I think it is common to run nixies off rectified 110, though I don’t mess with that stuff myself :)

• Gel Banana says:

Recalling from memory, 110VAC is RMS value. After rectified and filtered will give abt 155v. Nixie will still work but it wont be fully bright.
It would be wise to run it directly from mains. Use an isolation trasformer or hook up 2 transformeres back-to-back instead.

11. Brian says:

Of course since the logic sniffer isn’t isolated, you can still blow up the computer’s USB chips with the 180 V … A minor point I guess.

• Brian says:

Good luck with the events to Ian!

12. Electroalek says:

(0100 = 4) + (0100 = 4) = 44, but 0+1+2+3+4+5+6+7+8+9 = 45. What is the correct answer 44 or 45 ?

13. systemstech says:

So who won?

• Ian says:

Ernie got it. AFAIK it is 44. Though now someone will come along and point out how wrong I am ;) PCB code on the way.