Nixie bargraph clock - written by on 2015-11-18

Nixie bargraph clock

What happens when you combine an Arduino with something more vintage? Yes, a Nixie bargraph clock.

Recently I bought a couple of IN-9 Nixie bargraph tubes from a russian store, $1.5 each (quite cheap, huh?). These tubes are current driven, and they are fairly constant between 0 and 8 mA (Almost the end of the tube). Above that, sensitivity decreases rapidly. So, after keeping them in a shelve for some days because of not having any idea on what to do with them, I decided to make a clock.

A clock? - you might ask. Yeah, a clock. Neither analog nor digital. (Well, it is analog, but you know what I mean) Just the tubes displaying the time.

So, what do we need?

Obviously we're going to need the tubes and an Arduino (I'll be using a Pro Mini). Also, as the tubes run at 140v, an appropiate PSU is required. Mine boosts voltage from 8~32V to 100~390V, and it only costed ~$10. Also, I got a very nice wooden enclosure in a local store for just $3.

How to drive the tubes

The main problem about driving each individual tube is the voltage itself. The Arduino is a 5 volt device, and 140v would very likely release the magic smoke. To avoid this, a high voltage transistor, like the MJE340, will be used. The first problem is now solved.

Another problem is the lack of a true analog output of the Arduino. Instead, it uses a PWM signal. The easiest solution is using a low pass filter, so the output PWM will be smoothed, much like an analog signal.

Take a look at the schematic of one of the tubes:


<irony>Now admire the internal magnificence of the clock!</irony>


Quick description of each part

  1. Low pass filters and transistors for each tube
  2. 140V Power supply
  3. Arduino Mega (Right now I'm using a Pro mini)
  4. Tube connections
  5. Decorative voltmeter

Tube height

One of the problems of the tubes is that each one is unique, so under the same voltage and current, two tubes can have slightly different heights. To adjust this, the resistor located on the emitter of each transistor should have the appropriate value. You could also put a potentiometer for easier adjustment.

The final result!

So, how does this... strange clock look like? Here, take a look!

Final result

And there you have it! A steampunk vintage clock!

Tagged in Hardware. 0 comments

BabbageBot - written by on 2015-10-15


BabbageBot is a Python bot for Slack. Modular, easy to use and fun.

BabbageBot is a Python made bot for Slack, the communication tool for teams. The bot provides easy to add and easy to modify commands that can greatly expand the experience of chatting.

It was made with the intention of being modular, enabling anyone that wants to modify it to do the changes very easily. The structure of the bot is:

├── modules
│   ├──
│   ├──
│   ├──
│   ├──
│   ├──
│   ├──
│   ├──
│   ├──
│   ├──
│   ├──
│   └──
└── README.rst

The contains the main methods for connecting to the Slack API through a Websocket. An API key is required. This file also loads the modules/ enumerates all the available modules (aka commands), and uses this list as the message filter. When a string is detected to be in the list, this message gets delivered to the appropriate module. Result is then returned from the specific module and sent back to Slack.

The modules folder, as already said, contains all the modules that can be used by the bot. Each command should have its own file. Not required, but recommended.

For example, computes any kind of mathematical expression by sending the data to a server and then retrieving the result. Modules like the weather one require an API key. (In this case, from Openweathermap)

Adding a command is pretty simple. Create a .py file with any name in the modules/ folder. Then create the 'execute' function, with an string as a parameter (even if you don't use it). For example, I'll use the file '' (Fetches the Wikipedia). Inside the execute function I have all the necessary code to fetch the relevant Wikipedia article based on the given arguments.

After the code is properly written and working, an entry should be added in modules/ First, importing it (eg, 'import wiki'); and then adding the entry itself in 'commandModules'. In this case I would add ''wiki': wiki'. The first 'wiki' is the keyword the bot will be listening for executing the command specified on the second half, 'wiki'. You could also have ''potato': wiki', and then sending to the bot 'potato Trees' would return the Wikipedia article about trees.

BabbageBot is distributed under the GNU Affero GPL v3 license.

For more information on installing, modifying and redistributing, please visit this GitHub repository: BabbageBot

Tagged in Software. 0 comments

RSS is now working! - written by on 2015-09-24

The RSS feed is ready to use and read!

(Yes, right now almost all posts are about the server having new features. Sorry about that :3)

A new fancy feature started working just a few minutes ago! Prepare your RSS feed reader, for the most fractal-ish RSS feed ever. Really, take a look at this magnificent Menger Sponge:

Tagged in Server Stuff. 0 comments