Answer to the riddle

It is RGB LED matrix board!
RGB LED matrix

It is some PCB from Adaptive Micro Systems LLC, USA. This comapny specializes in LED advert production. From simple single color static board to full RGB color outdoor monitor.
Mine LED board is 72 x 24 RBG LEDs. With dinamic connection and some FPGA control. The protocol of the matrix itself was unknow, so I reverse engineered all the connections between chips and programmed my own FPGA code.
As it is FPGA on board, all reverse engineering was quite interesting and “solder free”. I just connected newly populated programming connector with my byteblaster and started software…

And after some time…
After all FPGA pins were traced, the only thing was created whole dinamic display with normal video data.
FPGA and RGB LED Altera
Here is some random data from clock counters.
It was very interesting: Red and Green LED are powered from 3V source, meanwhile Blue LEDs are powered from 5V source, also all logic chips are powered from 5V (FPGA has it’s own regulator on board).
This is very logical- blue LEDs have higher threshold voltage, RED can work at much lower voltages. So, to keep board cool (regular linear regulators on board), multivoltage PSU is used.

Check original post in Lithuanian language. There is interesting information in comments section.
If you have some questions, take a note, that this post was originally posted in 2008.

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This is starting post about very interesting project. Try to guess what it is?

This PCB is populated with serious stuff. Big square chip is Altera Cyclone EP1C6T144C8, 30 pcs of MBI5026CD, 8 pcs of HT04 (standard chips), 24 Fairchild power mosfets, 3 linear voltage regulators, one 18.432MHz oscilator, UTP connector with 4 LVDS lanes from FPGA. Byte blaster connector for FPGA programming and FPGA bitstream ROM. On other side there are 1728 components with total 5184 discrete active components.

I bought this item in ebay for $130. And it was very expensive for me.

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Mother China or USD rate fluctuation

When this post was posted, it was 2008 May. The exchange rate for USD was quite low compared to our local currency. Today (2015) we do not have local currency- we joined eurozone. And exchange rate for USD is quite high.

Continue reading

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For my laser experiment I am using collimators from old laser printers and copie machines. Especially from copiers.

A collimator is a device that narrows a beam of particles or waves. To “narrow” can mean either to cause the directions of motion to become more aligned in a specific direction (i.e., make collimated light or parallel rays), or to cause the spatial cross section of the beam to become smaller (beam limiting device). (source- wiki)

These devices are adjusted for copying process and IR laser. Meanwhile I need to use other settings. It is quite difficult to do this, as everything is very stiff and glued with some warnish.
laser collimator
First of all, remove all the parts if it is possible. Especially all plastic parts. Continue reading

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2D scanner, version 2

The first version of harware had serious problem- big geometrical distortion. So I added additional mirrors to lift laser beam. Also, I moved voice coils as near each other as I can. The finished scanner is much more smaller:
2d laser show laser scanner selfmade
I placed all optics as precise as I can- only 45 angles are allowed (this precise alligment was done using eyeballing only :) ). The result is much better, but still there is some other problems. Also, the voice coild have it own resonant frequency and in particular situations, the amplitude of the mirror angle is much higher. The main problem is my audio amplifier and Amiga computer emulation. I need low frequency amplifier working from DC to high pitch sound.

BTW, all laser mirror are “metal to front” type. They are salvaged from old copiers and laser printers. Regular mirrors have “glass in front” structure, so laser reflects not only from mirror side, but from the surface of the glass. Also, there is reflection in inner glass mass- the beam is reflected many times and lots of light power is lost.
For more information, google for “free space optics“.

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2D laser scanner, part 2

To test laser scanner from older post I am using very old Amiga software Lasermax. The Amiga computer itself is emulated with windows machine.

And just for fun, here is some laser beam experiments in lobby. Laser beam from red DVDRW laser is splitted by semitransparent mirror:

laser beam splitting
Continue reading

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2D laser scanner- mechanics

This real 2D scanner mechanics for laser beam. Not face ones with small DC motors, but real mirror system to form real image on some screen or fog.

All you need some real good laser source (I’ve used burnig red lasers from DVD recorders), two old hard disks. Some plastic/wood for base, hot melt glue and some electronics skills (or sound amplifier).

This is finished product:
2d laser scanner

This is one evening project and not very precise and perfect. First of all we need to cut voice coil and head holder from hard disk body. Remove read/write heads and glue small mirror to the axis. It is possible to make mirrors from hard disk platters.
Continue reading

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First nixie clock

In 2008 my programming skill was too weak, so I ordered nixie (neon glow tubes) clock kit. I had lots of ИН-12Б tubes in my stock, so I used them as my starting design. Tubes were connected to clock PCB with tube sockets, so I had option to swap and test some other tubes.

my first nixie clock

In this series of tubes there several special tubes like ИН-15 and other. They have various symbols instead of digits.

special symbols nixie neon glow tubes

This clock set is based on PIC16F876 MCU, there is step-up power suply on board.

For more information check original web page in Lituanian language (comments have some interesting links).

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old CO2 laser to cut … meat

We were recycling some medical equipment in 2008. And I found broken CO2 laser tube. So here is abridged translation of old article about laser tubes. BTW, after several years I bough hobby level CO2 laser for plastic and wood cutting. But it is another story…

It was “open core” or stream laser, with missing gas preparation system. The only use for it was to open and look inside for details. Output of the laser was 70W, meanwhile power suply for it was … 5kW. Not very efficient.
CO2 laser to cut meat of the humans

Here is some warning stickers/decals:
waning laser radiation
It quite powerfull laser, so warning is about scattered radiation. Even partial reflection can damage you eyes or burn your skin. (I managed to put my hand in unfocused 40W laser beam for short pulse and it hurts!)

All laser element were damaged by watter. But some components maybe are usable:
laser mirror zinc selenide
It looks like zinc selenide mirror. Or maybe semi-mirror. Or maybe it is just window to pass infrared waves from laser body to external mirror system. ZnSe is insoluble in water, so the finishing of the optics is quite good. But all gold plated mirrors were damaged.

Here is mechanical device with mirror/window installed:
laser mirror holder with micrometric screws
This is piece of mechanical wonder- it is sealed, but adjustable with micrometric screws.

The end of laser tube:
open laser tube holder
It is visible connections for watter cooling, gas flow (It is open tube, flow laser) fitting and high voltage connection.

Laser tube was damaged and cracked. And without gas preparation system, flow laser are useless.

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Repairing Nokia N80

Yeap, it was cool to have Nokia N8 in 2008. And it was cool to repair it… Original post from spring 2008:

This is consequences of certified repair of Nokia N80. Old metal case was damaged and was replaced. First of all it was not original part. Second- phones lost image on LCD screen. The other phone was bought and this one was left in the drawer. After some time “they” forced me to repair the phone.

Nokia N80 ribbbon cable LCD problems
It looks like, that certified technician crushed original flat cable with case and after some time it broke.

Nokia LCD cable broken repair N80 selfmade phone
Red arrow show the damage. I bought new ribbon cable in eBay and replaced. It was very strange, that parcel came from USA, not China.

Big thanks for Mr. Rolf2 for being very lazy to repair this phone and sending me the link in youtube with instructions about this phone disassemble.

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