the shop

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.

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.

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.

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!