robot porn

First Microprinter test

Inspired by Tom Taylor’s microprinter, I bought the first serial receipt printer on eBay I found, a BPM205 by Italian company APS (never heard of them, but it was cheap: 15,50 €). I was surprised that the printer was never used and came with all accessories: Five NiMH rechargeable AA batteries (can be used mobile, has IrDA), a 15V wall wart with 5 international adapter plugs, a CD with a manual and drivers and even a roll of thermal paper. Here is a pdf of the manual/datasheet.

I bought a MAX232 chip and 4 caps (1 µF) and soldered a serial adapter cable. I found Roo’s sketch at github and was able to get my “Hello world!” right away. Barcode printing also works (seems to be a standard). However, I get an extra “€” char before the Hello world on every reset (0xFF or 0×80 according to the charmap in the printer datasheet) and if I type something into the Arduino IDE’s serial monitor input it is only printed on the next reset, not right away.

Still have to find out what codepage the printer uses, it’s not the ISO-8859 charset. If I sent an “ü” for example, the printer outputs two characters – obviously the Arduino console sents unicode characters. (Also, my printer does not autocut the paper, so that control character is ignored.)

Links regarding the microprinter: Tom’s seminal project, Roo’s blog post, Microprinter wiki.

Update: The charset seems to be mostly Code page 850, but with some differences:

0×00 – 0×1F are not printable but control characters.
Ç (0×80) was replaced by €, as is 0xFF.
× (0×9E) is now ₧ (obviously borrowed from codepage 437).
ı (0xD5) is a smaller superscript 1, not a dotless i.
Except these anomalies, converting texts to be printed to cp850 should result in proper non-ASCII characters.

Oh no: More Arduino!

For more Arduino (and soon more open hardware) and other tinkering in German, have a look at my new blog/zine/platform/business thing over at bausteln.de. There is an Arduino workshop coming up in Berlin soon and I hope this will be only the first of many interesting adventures.

And about this English vs. German thing: I guess there are still a lot of people missing out on the most recent do it yourself stuff. Some people do not speak English at all and even more might understand it but get stuck when encountering technical vocabulary and American standards (22 AWG wire gauge anyone?). I think there is a niche here only slowly occupied by sites like freeduino.de or, now, my site bausteln.de. So we will rock this niche and move it a little more to the left, longtail-wise.

LilyPad Arduino stuff arrived

For the upcoming workshop(s), I wanted some Arduino variants to show around. The first batch to arrive today was a complete* set of LilyPad Arduino stuff (*missing the optional Lithium battery pack adaptor):

The board and LEDs, buzzer and vibration module are all working, still have to check the sensors. Missing from the picture is the spool of conductive thread to sew the boards onto fabrics. It was 20 € (ouch) but I guess 600m of thread lasts a long time.

More Arduino tinkering

This was just a test in LED matrix soldering and multiplexed switching, but everything worked right away with about twenty lines of code. Neat.

Update: Yes, this means I went out and bought an Arduino. Might become a business too, but sssh!

Arduino overview

Besides representing the overdue resurrection of this blog, this post serves as a reminder to myself: Finally get an Arduino board and have some fun with it. Make magazine’s blog has a comprehensive overview (a “gift guide” for the holiday season) that works very well as a beginner’s explanation of all the incarnations and add-ons for the microcontroller board family: Arduino Gift Guide!

Every table should be like that

Who wouldn’t like a giant coffee table NES controller? Awesome:

Built by a guy named Kyle Downes. (via BoingBoing)

hardhack partially too hard for me

I’m sort of chickening out of the upcoming hardhack event, at least on friday, tomorrow. Mainly because it’s Josi’s and mine anniversary and this is not the kind of pastime she likes to be dragged to, even if half of hardhack’s speakers are women (which certainly helps with the “I can’t do that” problem, but no inch with the “I’m not interested” fact).

Additionally, I like that hardhack sets its standards pretty high, very much unlike e.g. MAKE magazine, which I still love, but where I sometimes feel that they have very very basic projects that should annoy anybody who ever held a screwdriver before. But, coming back to hardhack and the interesting workshop on how to hack your wireless router and use OpenWRT on it, this might be a little too much for me. Opening the thing and soldering a serial port to it – no problem, can do this all day. Compiling your own firmware and knowing what to do if it doesn’t work – problem, at least for me. And it seems the wifi component in the T-Com router I have here is not supported yet, anyway.

So, if not tomorrow, I definitely plan to have a look around hardhack on Saturday and I’d love to participate in Sunday’s nerdtour of the pneumatic tube mail system (aka. Rohrpost) that once existed in (or rather under) Berlin.

Hacking/music in Berlin

Tonight in Berlin: Yamaha presents its new Tenori-On musical instrument at Berghain club (entrance free):

The TENORI-ON is a unique 16 x 16 LED button matrix performance instrument with a stunning visual display. For DJs & producers it is a unique performance tool enabling them to perform using MIDI and load the TENORI-ON with samples to jam and improvise within their set BPMs.

By operating and interacting with the LED buttons and the light they produce you gain access to the TENORI-ON’s numerous performance capabilities. The TENORI-ON provides six different performance and sound/light modes for broad performance versatility, and these modes can be combined and used simultaneously for rich, complex musical expression.

And from 18. – 20. April 2008 there will be a hands-on hacking workshop in Berlin-Mitte called hardhack. The preliminary schedule:

Friday, April 18th:
12:00 doors open
15-18 Room 1: wifi access point workshop with Stephanie Lange

Saturday, April 19th:
10-13 Room 1: unzap workshop with fd0
10-13 Room 2: sound and motion triggered photos with Nadya Peek
13-15 lunch break
15-18 Room 1: microcontrollers and eeproms with Daniele Bianco
15-18 Room 2: white noise/RNG/high frequency sniffing with xxxxx

Sunday, April 20th: free day to do what you want.

There is a certain possibility of meeting me on those two occations.

Lazy Sunday Afternoon

I just found this superb painting by Brandon Bird called “Lazy Sunday Afternoon” on the MAKE blog:

It’s Christopher Freaking Walken building a robot. How cool is that?

(The artist has prints on sale. I want one.)

One Laptop per childish adult

My XO Laptop has arrived. After a short detour via Austin, TX (thanks for ordering it for me, big cousin) and almost three weeks of United States Postal Service limbo it finally is mine. (Okay, the German customs had some fun with it which allowed me to sit in their Berlin office for almost 2 hours and watch the painfully slow processing of my packet. Think as east block style agency meeting slow motion village post office. Only slower. Finally I could have it for only 18 Euros of tax after convincing them it was a gift as well as a toy.)

Of all the 400 color combinations of the logo I of course received the one clashing most with the laptop’s green plastic: mint and sort-of dark green, both quite off the main hue, ah well. I’ll learn to love it.

It doesn’t look as small as it is next to my 12″ Powerbook, most likely because the Powerbook is not so big to begin with.

This is more accurate although I may have extraordinarily big or small hands, so maybe it is not so informative as a picture.

So what am I planning to do with it except for showing off? First, there are some interesting programs (”activities”) already installed, the most interesting being the TamTam SynthLab, a Max/MSP based visual synthesizer modeler. Here’s a video of SynthLab in action. There is another activity called Measure which is a very simple oscilloscope. The XO’s audio input accepts a wider range of voltages compared to regular  computer soundcards, so it can be used as a flexible A/D converter.

A lot of improving and hacking of the XO is currently done and all over the web. Some people want to increase the analog input’s versatility by a usb powered probe circuit to enhance the oscilloscope range. On the software side, because the XO runs on an adapted Linux distribution (with custom “Sugar” interface), we’ll certainly see a lot of applications being built for it in the near future. About 80,000 laptops were sold to individuals like me, so a lot of them are now in the hands of hackers and tinkerers.

And finally, the XO may have a lot of differences to regular laptop computers, but in the end it is a computer by design, so even if development for its regular system stalled, there will be someone putting together a special Ubuntu distro. So, no worries that this system cannot be used for something in the end. It does already run Doom.