Archive for category programming

Migration hell: moving printers in Windows

Our campus, Faculty of Architecture, VGTU is moving to the totally new subnet. As we use DHCP for IP distribution, no real problems except `sed` are going to appear.
The pleasing moment is we are getting a fresh IP range.
The headache is TCP/IP printers.

WPKG has good printer addition/ installation guide in , but it does not cover changing IP port numbers.
As a CEO on all computer infrastructure, I need to find any solution to make the movement smoothly.

I was unable to find a ready-made solution, and in-house tool appeared after several hours in the Net.
I need to apologize for bugs and errors, as it is the first (and hopefully the last) VB script. It uses WMI. Testing box was W7, x64.
Maybe someone will find it useful.

Call the file chprinterport.vbs Read the rest of this entry »

Weekend project – USBasp

I had some ideas to go out before, but as i got terrible cold last Friday, I had to postpone all of them.

I feel a bit better today, so decided to build USBasp – an USB port ISP programmer for Atmel product family. I used STK 200/300 dongle before, but it works from parallel port only.
USBasp: fresh PCB
Lets start: the schematics is from . You can find some schematics and pre-routed PCB’s there.

What I need is USB B type or MiniUSB connector, SMD parts, small footprint, single – sided PCB. The one I liked is by Thomas Pfeifer, The problem is I found no files for Eagle there and had to re-create the PCB.

Additional features are:

  • RC filters on MOSI, MISO and SCK lines to suppress ringing, as suggested in AVR Freaks forum;
  • Signal from oscillator (XTAL1) is routed to the pin 3 on IDC connector via jumper – a handy feature to debrick the MCU if you accidentally fused external oscillator;
  • Inductor on the power line.

The PDF files with the layout are here, an A6 – size mirrored image for direct printing on OHP is here.

Added on 2008-10-01:
USBasp top side, populated
USBasp bottom side, populated
First, it works. Both connected directly or via USB hub.
Second: don’t create anything while you are ill. Actually, pin number 5 on miniUSB connector MUST be grounded, while pin number 4 can be grounded or left floating. I’ve used i jumper wire to solve the issue.

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Quite interesting article on image processing. The MatLAB source, presented on the site, need some minor enhancments. Authors may contact me, if they want ;).
Attention: the program is really slow. I used ‘direct solver’, and it took almost 10 minutes to proceed the image.

JPEG-2000 in MatLAB

Any idea how to produce and read the JP2 file in MatLAB?
The easiest way should be writing middleware in Java to specific library. The things are complicated, as i need to get and modify data from every stage of encoding/decoding, like color space transformations, quantization, EBCOT (including bit-plane decomposition, bit-plane processing, encoding) and rate-encoders. Read the rest of this entry »