My first thought was to use the avrlib, so I wired the LCD and started to use avrlib, but I quickly run into issues. In fact, I want to use some icons on, and the avrlib seems to be buggy.

After a little compile/test/run/compile, I remember an old post on a website about KS108 chips. I find it back, it’s on the science prog

This is really great, you can build some custom fonts easily (that’s exactly what i’m looking for)..

Here a couple of pics…

As you can see, I use a ATMega32 (on a futurelec card), a simple pot for the contrast, and the lumex.

I can use a mix of different fonts on the same screen.

And I can even display some pics too :)

Here the famous tux.

I still have to deal with menu and other stuff, this should be a little harder than expected, but will be nice. If somebody know a good library to use on a T6963C, please post a comment..

For users who wants high res pics, you can find them in my gallery (as usual).

A good friend, give a old Mullard DH7-11 tube, so it’s time to give it a try no ? ;) The main issue right now, is to find the power transformer to light this big guy

Finding old part is always hard, but the best thing is to keep on trying. I finally found a transformer builder at great price on eBay.

400v / 5mA transformer isn’t really common, you know.

For everybody who want to know what a scope clock is check this.

Enjoy Ray ?

This one use quite the same stuff than my previous I IV-18 clock, the main difference is the VFD power supply, but if you read this weblog, you will understand easily. I will publish the whole design and source code for free soon.

Anyway, here some pictures:

The PCB made with toner transfert

Soldering SOIC isn’t that hard ;)

The beast

The VFD tube is really big, and nice no ?

As you can see on the latest picture, there is a little gradian due to the filament supply. I haven’t find a simple to use (as the MAX6921) VFD driver that support AC filament. (MAX6931 is to small for hands soldering)

Enjoy :)

Ok .. so I decided to use a Maxim VFD driver: the MAX6921:

• 20 outputs
• 4 wire serial-interface
• supply voltage: 8v / 76v
• 40mA output

The main issue is that it only exist in a SO package, so I need to use a little adapter to use MAX6921 on a veroboard .. (I bought this at my local store, but they cost twice the price of the MAX)

The next step, is the clock itself. For my nixie clock, I tested several stuff like 50hz (mainlines) sync, or external oscillator but this isn’t accurate enought. This time, I decided to use a plain old DS32kHz crystal oscillator. I’m pretty sure this won’t loose a second in a week ;)

To finish the clock, I need a micro-controller, as I need a really little amout of IO (2 for buttons, 4 for the VFD driver, and 1 for the oscillator), I decided a ATtiny2313 could do the job perfectly and give me the enought room for other stuff (like a LDR for automatic dimming)

So, here the final schematic:

The full schematic

It’s the first time I used the ATtiny2313, but AVR-GCC is a great tools so.. To program this little stuff, I used the in-circuit programming, check out tuxgraphics doc for more infos about the whole stuff.

That’s fine, but does it look great ? ;)

Hum, yeah ! ;)

Here the (quite) finished product

And if you look closer at the VFD:

And the finished product :

Download

You will find a complete archive file here, it contains:

• All the sources need to program the ATtiny
• All the schematics to build you own ;)

/Enjoy

Here a little pic of this big guy:

As you can see this is quite large, and really nice looking. I spent a little time to figure out, how to make it working (reading russian isn’t really easy). After sending a mail to the NeonNixie group, Chris help me to fix my issue.

So here the IV-18 pinouts:

And the values:

• power supply for a digit : 20v-30v (if not muxed)
• power supply in muxed (for the 9 digit): 50v-70v
• the filament: 4.3v-5v at 100mA

The first step was to build the PSU

Power Supply

I want to build a small clock which feet in a small box without the use of a wallmart (external) transformer. So I went to my junk box, and found a small 2x6v – 350mA transformer. Hum, after a little test, I found that using this with a voltage doubler, I can get around 40v. Beside I should use 50v in muxed, I discover that 40v is far enought, and It will save the VFD life. (even if this kind of VFD should live at least 10 years without issue)

That fine.. but I need some 5v too. My first thought was to simply plug a 7805 in the middle of the voltage doubler… That works fine, except the 7805 is really hot, and need a large heatsink. So I decided to use a switching PSU based on a LM2575.

Here the final power supply. (as you can see, I added a diode the filament PSU to avoid it to glow too much)

Here’s a pic:

You can see

• the transformer
• the two caps and diodes from the doubler
• the LM2575 and its parts
• the ATtiny2313 (micro-controller used to do the logic)
• the DS32kHz (32.768kHz Temperature-Compensated Crystal Oscillator)
• and the little plug I used to do the in-circuit programming.

So this is the first of a short serie of article, on my nixie clock. Beside I want people to be able to reproduce this for the own purpose, I choose to use some really common stuff, and cheap too.

The first step, is to buy the nixies and the nixies drivers. Every month, the nixie price tend to be higher .. so..

I bought some nixies on eBay. This is a good place to find some, at a decent price. Jan have some at good price too. Take care that a lot of website, buy some tubes on eBay and sell them after. (with a very large price increase..)

So, first choose the type and size of your nixie, Dieter website is the best place to look at the nixie specs. After look at the corresponding prices on eBay. Some users reports receiving broken tubes, but if you choose a serious vendor, you won’t have this kind of problem.

Here is a couple of pics, on the first nixies I bought. It’s some IN-8-2. They have a good price, a good shape, and quite good size. Bigger nixies cost a lot to much money for me.

The next post, will be about powering and testing a nixie with a generic microcontroller and a simple power supply.

Feel free to ask questions Bye bye..

For those wondering what is a nixie. Take a look at Wikipedia

And a nixie clock look like this:

There is a couple of hard stuffs to fix for that:

• find the nixies (ouch prices)
• build a custom power supply. (~170 VDC.. not really easy without external transformator)
• find a way to drive the nixies (BCD drivers with 250VDC are hard to find)
• find a way to have a working clock. Crystals aren’t really stable with temperature.. perhaps a DCF77 module is the right way
• Build the stuff without too much pain, and too much money.

That sound funny ..so let’s give it a try ;)