Thursday, March 1, 2012

NTP Nixie Clock

So I have been chugging away on my design for a Nixie alarm clock, but first decided to make a Nixie clock that could communicate over the network. What better functionality to add, than syncing via a NTP server. I am not a fan of reinventing the wheel. So I am basing my design on one I found already. I found someone who had previously done this project: see here. I noticed he based all his coding, etc. off of NTP synced LCD clock, who has a nicely implemented TCP stack they have posted under GPLv2 (I looked around for the original source, but was unsuccessful for now). The schematic after being put together looks something like the one below.

Essentially, this takes a 9V wall wart and turns it into the +3.3V & 5V needed to run the ATMEGA and the ENC28J60 Ethernet chip Then, as is standard for most Nixie drivers, it uses a 555 timer and a discharge capacitor to drive a switched 180V DC line. As is also pretty standard, it uses two 74141N drivers to actually drive the cathode of the tube itself. These chips can handle being connected to the relatively high voltage Nixies.
The anodes are driven by a simple series of step-up transistors hooked up to 3 output pins on the IC.

The Ethernet chip is very well documented, and is hooked up according to the datasheet, nothing too fancy there.

At the bottom of the site linked above, the code is available. It essentially is a replica of the Tuxgraphic NTP clock, with the driving of the LCD screen changed to be the driving of the Nixie Tubes. There are a few things I am going to change in the program, if I don't end up scrapping it altogether. I don't want my clock having a static IP address. I also think I will have it update my time more often via NTP. I do like the idea of displaying a date and having the cathode poisoning.

First attempt at making the clock DHCP: It worked, HOWEVER, it made the resulting binary about 35% too large to fit on my ATMEGA168, and that wasn't even with NTP updating added in.

On a last note for now, I did get the board designed in EagleCAD, and sent off to get prototyped. Hint: For $35, I was able to get 8 professionally produced boards. If they turn out ok, I might even hold off on my research of UV LED PCB Etching.

For now, project is on hold until I get in my 74141 drivers (ordered 3 weeks ago, so hopefully soon). The good thing is, all the changes I want to make to this are in software, so it will be easy to change as time goes on. Unfortunately, I am probably going to have to upgrade to a 328 too get additional flash space if I want to go much further with this iteration. But only time, and some fancy coding will tell.

Wednesday, February 15, 2012

Old Fashioned

So, I have been perfecting my ideal old fashioned, and here is what I have so far:

In an Old-Fashioned-Glass, combine ice with:

60 mL Makers Mark
30-40mL Turbinado Simple Syrup
2 dashes angora bitters
2 dashes orange bitters
splash of mineral water

Stir for 1-2 minutes, then let sit for an additional minute or two.
If you have orange rind, a nice topper is rubbing the orange rind on the rim of the glass before putting it in the glass.

What I am missing: The perfect ice-cube


Tuesday, February 14, 2012

3D Printing

My self-proclaimed weakest link throughout all my electronic projects is mounting, building, etc. I decided to overcome this issue, and have recently purchased all the parts required to make a RepRap Huxley.

I will document my build process once I receive all the parts - both for your sake and mine as I inevitably will break it and having a build log is always nice.

I chose the Huxley over other 3d printers primarily due to its cost and size. I do not have a big place, and I am unsure how much I will use this, so a cheaper option is better. If I outgrow it, I can just print me a new one.

I hope mine look shalf as professional as the one on the left.

Print area: 6" x 6" x 4"

Power Supply Snafu

Yesterday, I went to turn on my power supply to power my latest tinkering, and I let the magic smoke out. Apparently at least 3 capacitors and 2 transistors blew from my visual inspection inside. It had lasted me many long years of tinkering, and I happened to have an extra ATX supply laying around from my last computer upgrade.

I opened it up, found that it already contained a load resistor across the +5V supply, something that I remember was needed for the power supply to work correctly.. A little testing and I found I had to drop the green wire to ground to get it to turn on. I drilled a few holes in the top to make room for my binding posts, wired one each to the -12 (blue), GND(black), +3.3(orange), +5(red), +12V(yellow) terminals.

In addition, I hooked up the brown (sense) wire to the 3.3V wire. I also decided to throw the whole circuit onto a separate switch on the top of the supply, so I hooked the green/black up to a SPST switch on top. I kept the wires long to allow easier future modification.

After turning it back on, I found out my rails were easily sitting within 5% of the advertised voltages.

The end result: My lab is now back up and running with my new power supply, and I now have a lot more scrap parts from my previous supply. Now back to making a pin-out of my nixie tubes for my clock (more on that later)

(Future upgrade plan: add a variable voltage from 0-24V using -12/+12 - drawbacks - space within the supply itself, possible add a small bot on top to host the circuitry. For now, I will use a small breadboard 4-25V, 1A variable supply. I have)

Welcome to my blog

I plan to keep a log of some of my electronic projects, as well as some of the interesting problems/solutions I run into at work as a Network Admin. Heck, I might even throw a hint of two about desktop computers. Maybe I will throw a few recipes out there (for those with an iron stomach).

Projects in progress/in the future:
- 3D Printing
- Fix ASA 5505 (no power)
- Build myself a new alarm clock - Nixie tube displays, mounted to my bookcase.
- Automatic Watering system for my plants (I am forgetful)