Savel brain dump in English!

PCB component are getting smaller and smaller. Hobbyist must learn how to handle such miniature components and how to solder it.
Some small parts are already described in old Lithuanian article about soldering LED driver on selfmade PCB. Next PCB are with tiny traces too…
This is sample from Texas Instruments, TPS61058DRCR- “sync boost converter”. Quite good white LED driver for Liion battery pack. Up to 1A for LED chain.

General view. I repeated PCB image three times in case I’ll have problems with traces.

Closeup:

Other angle closeup:

24 time enlarge:

Scale is 1mm between numbers.

Yeap, time passes and English translation is lagging very much. I’ve already sold this car… Now it is the end of 2011, original post date is 2008…

This is abstract from full Lithuanian article about connecting computer to automobile to check engine, brakes, air bad and other stuff.

As my car made some strange effects, I decided to build adapter and to check it. Also, this could be great article. Now it is cheaper to buy China made device.

Adapter converts K-Line, L-Line, ISO9141 to RS232

Components: MAX232, MC33199, 78L05, one transistor and small stuff.

Circuit:

Big image. Warning, ther is small error in image, but circuit is working!

Continue reading →

Dimmer, from the word “n. dim, v. to dim”. Simple device to make light of incandescence lamps lower. Also, used to slow down colector motors. All this started because Lithuanian internet is full of old soviet circuits with archaic components. Meanwhile “other” world is using much better way to dim lamps.

Circuit is copied from real world China made halogen desktop lamp. Power of the lamp was about 100W and this circuit is typical.

In real world this looks like:

Component selection is not very critical: triak BTB04-600SL (ST semiconductors, 600V, 4A, trigger curent 10mA), diak or trigger diode- DB3 ( “fire at” 32V), inductors was about 3mH. There are lots of versions of this circuit in the internet. In one version I saw 50uH inductor, T0609MJ and BR100. Just check if maximum allowed values are not outmeasured.

Also, it is posible to find triak and diak in one package. I found one packade silicon device in some vacuum cleaner. As power of motor was about 1500W, triak-diak was with small aluminium cooler (~8 square centimeters).

WARNING!
This circuit is galvanically connected to live circuit. Do not touch the wires unless you want to be electrocuted.

More circuit collected from internet:

C1, L1- apsauga nuo radio trugdžių. R4, C4- apsauga nuo atsitiktinio suveikimo dėl tinklo trugdžių.

R4, C3- apsauga nuo atsitiktinio suveikimo dėl tinklo trugdžių.

L1, C1, R1- trugdžių sugertukai. R2- kad išsikrautu C1 atjungus iš rozetės.

It looks like thaw. I think it is perfect time to dry some snow:

I wish you Merry Christmas and Happy New Year!

Just testing system to spam facebook with my weblog posts. It is simple WP plugin and Facebook aplication.
Aplication is working from http://apps.facebook.com/braindump

I don’t know very well about php and advanced wordpress technology. But new and clean install of wordpress 3 on my computer failed.
When I go to admin page I see error, that website didn’t respont. Apache returned zero byte answer… it was strange.
In Apache log there are lines like this:

[Fri Jul 16 21:53:27 2010] [error] [client x.x.x.x] ALERT - canary mismatch on efree() - heap overflow detected (attacker 'x.x.x.x',
file '/home/testing/public_html/wordpress/wp-admin/includes/template.php', line 3553), referer: http://blog.savel.org/

It is php crash.

So I commented 3553 line and everything is working fine… Now I can see dashboard, users, but I can not see links and other admin pages…

What this fucking line for?

$screen = (object) array('id' => $screen, 'base' => $screen);

My computer is running Linux Debian current stable version. No fancy configurations.
(Server version: Apache/2.2.9 (Debian), Server built: Apr 19 2010 19:57:58.
PHP 5.2.6-1+lenny8 with Suhosin-Patch 0.9.6.2 (cli) (built: Mar 14 2010 08:14:04)
Copyright (c) 1997-2008 The PHP Group
Zend Engine v2.2.0, Copyright (c) 1998-2008 Zend Technologies)

What interesting you can do with needless Pentium 4 or similar Celeron processors?

First of all you need to find 6 processors of one type. I wanted to use AMD processor, but dimensions of its housing are a little bit different. Thus I chose 6  Pentium 4 processors, the old ones with small legs.

The following processors were used for the experiment:
Pentium 4, 1.9GHz/256/400/1.75V
Celeron 2.8MHz/256/533
Pentium 4, 1.5GHz/256/400/1.75V
Celeron 1.7GHz/128/400/1.75V
Pentium 4, 2.4GHz/512/533/1.5V
Celeron 2GHz/128/400/1.525V.

All models were quite old. All covers were simply removed for the exception of one. Its crystal was soldered to housing with special solder. This special solder made me some troubles when I soldered the final product:

The cube came out a little bit crooked, but it can roll out several gigahertz and megahertz

It’s quite heavy, as housings are made form red copper and nickeled. When you heat one side of it, the other became unsoldered…

After various financial speculations on the Internet and in real life, I gathered some money and bought through eBay auction Altera Cyclone III Starter Board. Another “starter board” is rambling somewhere in the post.

I appreciate deeply all my countrymen who bought text mode LCD monitors and thereby sponsored my FPGA studies.

I have gathered graphic LCD monitors from old devices (mostly from copiers). That’s simple monochromatic LCD monitors without controllers. An image should be dynamically tranferred from controller for these monitors. There are SED1351 or similar graphic controllers mostly. Maybe it’s possible to find a datasheet of SED, but not to find the monitors. I’ll try to look into several LCD monitors with the help of an active board.

By the way, these monitors often need negative voltage supply. The main logic is powered from 5V.

LCD monitor named “EDMMPU3BDF”, the white blue monochromatic graphic monitor 320×240, mostly has a touch screen.

1. screen_on (0-off, 5V- on)
2. nc
3. VSync
4. HSync
5. pixel clock
6. Vcc, +5V
7. GND
8. Vee, -25V (the same as pin 13)
9. D3
10. D2
11. D1
12. D0
13. Vee, -25V
14. contrast, ~-18V

Standard protocol is shown graphically (oscillogram):

Big picture for printing.
WF signal is used in several LCD circuits to generate the alternating current through LCD crystals in order to protect metallization from erosion. Not all LCD monitors use this signal. There is simple logic signal, which changes to each picture.

I found the information about optical mouse hacking on the Internet (http://spritesmods.com/?art=mouseeye). I had been looking for such mouse for a long time. The first which I found, had defective optical chip. But the second was more succsessful. 

You need to find an optical mouse of the older model, where the optical chip has 8 legs. A mouse of the new model has only one chip, where all interfaces (USB or PS/2) have already been integrated into the same chip.

The program was not written by me. However everything is quite clear. All data – change of coordinates and even the view under the mouse pad are read out through 2 wires. Here is an image got “through mouse eyes”:

Here is a scanner mode:

A connection scheme is very simple – the mouse is powered from 5V. Connect SDIO pin and LED’s anode (+) to the 12th leg of printer port, LED’s katode (-) – to the 5th leg and SCK – to the 9th leg. You need to check if mica and LED (mouse elements) are connected. Then disconnect SCK and SDIO pins coming into mouse controller. The collocation of optical chip (ADNS-2610, A1610 or like) is  following: 1 and 2 – mica, 3-SDIO, 1-SCK, 5-LED controll, 6-GND, 7-Vcc(+5V), 8-RefA (here a small capacitor is connected).

The software is the same as in original post. As my LPT1 port has burned out, I added additional I/O addresses of PCI board.

You can download source code and compiled MS Visual Basic program. There is one dll file (inpout32.dll) which you should copy to windows/system32 folder.

Mouse scanner software (binaries + source code).