Symbol Engine

I made a single side board version of USBTinyISP for easy etching. But I failed to be the first on the internet. Apperently Wraimann beat me to it.
Never mind, this one is much smaller at the expense of leaving out the 10 pin socket. You can always make an adapter cable anyway. It also contains thicker lines to avoid accidents with etching.

USBTinyISP is a very versatile USB AVR programmer by LadyAda that works with nearly all Atmel Microcontrollers.

Downloads:
USBTinyISP Eagle Files @ Symbolengine.com

I’m sorry for the loooooong downtime. I was having problems with my db and didn’t have the time to fix it until now.

I have been working with Tolga on a 4 motor walker. After taking care of the electronics we started working on walking dynamics. Figuring out the timings needed to control this beast wasn’t that easy. Luckily Tolga had a working Wowwee Roboquad lying around. So we had a chance to analyze its walking patterns.

Here is the basic schema of a 4 motor walker. You can see the numbering scheme we used to identify each motor. Arrow points to which way the robot is going when we say it is going forward. Motors are running counter-clockwise with negative voltage and clockwise with positive voltage. Now to get to the juicy part:

• Please note that the patterns for rotating are 2 times longer than the patterns for movement. As a result turning is slower.
• If your robot is moving in very small steps, try longer delays between steps.
• If the robot is moving faster in one directionor leaning slightly to one direction while walking, there is probably a problem with its weight distribution. Try to distribute the weight as equally as you can, especially between back and front

wmii has been the my window manager of choice ever since I first saw it. I recently got a shiny Dell M1330 and as anyone can guess Vista did not live longer than 2 hours on it. I had never used wmii on a laptop before and I saw that the default scripts are were obviously coded with desktop user in mind.

• There is no battery indicator
• You can't watch the CPU temperature
• and you can't set the CPU frequency governor

(more…)

I finally had the time to try out Spaceman Spiff's Color Fix on my DTV. So I took my DTV apart , heated my soldering iron and tried to focus my eyes on the teeny weeny resistors. First let me tell you this: Piggybacking Surface mounted resistors is NO PICNIC.

You need completely steady hands, eagle eyes or a stereo microscope, a really good tweezer to grip the tiny resistors, a soldering iron with heat control and a good quality soldering& paste flux. I had& none of them. After 2 hours of agony I could only solder one (1) resistor into place. Then when I accidentally touched the one I soldered when I was trying my luck on the second one, the first one came off… Complete with the original resistor on the DTV board. Talk about pain.

I left everything on the table and fired up my a1200 to normalize the levels of stress hormones in my blood.

The other day I decided it would be much easier to take the original resistors out and solder new ones in than to try to piggyback them. And here it is, the turning point:

Spiff's page says these resistors should ideally be 165 ohms. What I had in hand was the 220 ohms resistors I prepared for the easy fix. The ones on the board where 680 ohms, so I decided to try my luck. 220 ohms is much closer to the ideal value than 680. I soldered them in and as I thought it was much easier.

The result is as anyone can guess, not as good as the original fix, but is much better than the original buggy board. It would have been much better if I had resistor with a closer value to 165 ohm. So I dub this fix Half a Spaceman Spiff's Ghetto Color Fix, or HaSSGCF.

So the moral of the story boys and girls is, it's much easier to replace SMD's than to solder them piggybacked if you don't have right tools.

I got meself a PAL DTV recently. These things are pretty cool out of the box. But if you want to get more out of your DTV, there are many hacks around the net. Here is a checklist of the hacks I want to make for mine. It may prove useful to some people.

I'll add my experiences doing these hack here somewhere when I find the time to do them.  

1- Fix the colors:

    PAL version of the DTV is cursed with a buggy video generator. White is not white at all, and some colors are very hard to distinguish. If you don't like your DTV with ghetto colors, try spacman spiff's easy colorfix: (scroll down to easy and better fix)

Spaceman Spiff's DTV colorfix

Note: I have tried this hack with limited success. You can read about it here.

(more…)

Since 1200 schematics were so popular, I made A600 schematics into pdf format too. I have changed the layout of some pages, and joined hard to follow schematics that were scattered on multiple pages. Enjoy:

Amiga 600 PDF Schematics @ Symbolengine

Amigaguide is a hypertext document file format designed for the Amiga, files are stored in ASCII so it is possible to read and edit a file without the need for special software. However it's not pretty to read it with a text viewer, because links don't work and formatting clutters the text.
This little tool I wrote converts uploaded amigaguide files to html and displays them directly on your browser for viewing. If there are external files linked in the document you can just save the output page to the same directory as your guide file and links will work.

I hope you find it useful.

Amigaguide to HTML converter @ SymbolEngine

GP2x is a wonderful device for its portability, power consumption and price tag.  You can do pretty amazing stuff with an out of the box unit. Here is a slice of that:

1. Go to settings/system menu on your GP2x
2. Make sure the IP Address is 10.1.0.1
3. Turn on telnet, ftp, samba and web servers (You wont need samba if you are using a real operating system)

(more…)

Copy protection schemes don't work. Companies pay huge amounts of money to develop a new copy protection scheme, only to be cracked on the first week it hits the shelves. Then they want us to pay the companies back the money they used in developing the already cracked copy protection scheme. But we don't want to pay the ridicilous money for a plastic disc with data on it so we copy. 

Alternative:

Companies do not pay huge amounts of money to develop new copy protection schemes that don't work and admit the fact that data on any media will always be copiable, no matter what anyone does, just like the Beta or VHS tapes before them. Because they don't pay for encryption schemes, media becomes cheaper. More people would like to buy original HD-DVD or Blue-ray discs because everyone likes to own the movie they like in its original package. Some people still copy, but they always do anyway.

Just give up the ridiculous fight!