Referral spam removal

In the middle of the night I was checking my Google Analytics statistic about my website. Where did the users came from, what articles did they read and stuff like that. In the first moment I saw that a lot of users come from other websites like, Interesting, why are they directing visitors to my website? I started to be happy, what a nice thing from them, but I was wrong. After looking up more on Analytics I found a lot of similar referrals.

fig. 1 – list of spammer domains

At that moment my happiness turned into anger. What should I do? Should I contact them and ask to stop it? Naaah, they probably wont even read my mail. Should I contact my domain host? Naaah, takes too long to solve anything. If I want to solve it fast and effectively, than I have to step in.  In fig. 1 you can see the lost of spammer domains.

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DIY Resistance spot welder (RSW) – part 1

In these article series I am going to build from scratch a mini spot welder for welding lithium batteries and other small metal objects. Before anything else, we need to define what is resistance spot welding and why it is widely used.

Have you ever shorted a car or lithium  battery? Or the mains power outlet? And what about a charged up capacitor? Have you noticed the sparks? That was almost a spot welding, that what resistance spot welding means. You let electric current (high current) through two metal objects pressed together. You concentrate a lot of energy into a small spot, where the voltage drop increases and the heat is generated.

fig. 1 – basic model of RSW

On the first figure I have tried to represent a basic spot welding scenario, lets see what those red and green spots represent.

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Arduino illuminated sign

Nowadays led signs and banners are getting more and more popular, also their price is going down slowly, but personalized ones still have a spicy price, so I`ve decided to make one by myself for less than 30$.

I wanted to lit up every character separate in order to make it look more interesting and professional, so I had to use a cheap and small Arduino Nano board.

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Rewinding a microwave oven transformer (MOT) for general purpose use


In this article I am going to present my struggling about rewinding a microwave oven transformer (MOT) in order to make a low voltage (20-30V) but high current (15-30A) transformer. I have done these experiments in order to make a cheap but a very handy transformer for a bench supply. These types of transformers 500-100 VA transformers cost hundreds of USD where I live, but these microwave oven transformers can be purchased for a few dollars used, because they can be only used for special applications (like where it comes from, microwaves). They usually get shorted or interrupted on the secondary winding due to the high voltage, poor insulation, thin aluminium cross section wire. Many times the primary winding remains intact.

Before starting with the practical work, we have to settle a few theoretical consideration, and proving them in small scale.

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Using a six wire stepper with an Arduino Uno and Adafruit V1 Motor Shield

In this article I am going to present the basics about using a stepper motor with an Arduino Uno and an Adafruit clone stepper shield.

There are many kind of stepper motors around. From small ones that can be found in digital cameras to bigger ones that can move huge CNC machines back and forth. They usually come with 4, 6 or 8 wires, but they can have even more wires, and special techniques to rotate.

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Home made bench power supply

A bench supply always comes handy when you play with electronics on a daily basis. As anything else – if something comes handy you have to pay it`s price.
These supplies are quite expensive compared to the price of what is made of – basically you pay the engineering not the parts that are made of.

Main parts

Because I was in the need of one bench supply I made my own, out of a few cheap components so I have spent 10 bucks(USD).

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Sony Play Station Portable (PSP 1004) display replacement

Today I`m going to show how to replace the display of a Sony Play Station Portable (or just simply PSP) model 1004. This was one of the first series of PSPs, the fat model, one of the most popular handheld consoles on the market.

It is still popular but its reputation decreased caused by the newest model, the Ps vita and due to the increasing market share of smartphones. I think smartphones are just great,…but not for gaming. It’s a pain in the ass when playing FPS, racing or sandbox style games. The graphics can be great, but – the gaming experience and control is way beyond what it should be.

But thats all for the introduction and history class, now lets see whats inside the box and how to fix it. I’m going to guid you trough the main steps involed in replaceing the display of this beauty. Enjoy the video.

A micro PHP framework

Every time I begin to write an article it is so hard to start. So now I`m going to keep it simple and straight. Lets see it.

I few days ago I started to work more seriously on a project, but it was quite interesting how to start it. I am familiarized with Symfony 2, but I consider it is a too heavy and big framework for what I want to use it. But it is too big to do it in plain PHP, it`s nonsense and I will end up in spaghetti code with lot of bugs and security holes and also will run slower than Symfony would do it.

I made my little research about using standalone Symfony components, and actually here is what have I done. A small, easy to overview and fast (theoretically,…) super-micro PHP framework which suits best my project I am working on (based of course on an MVC-ish pattern). You can find it on Github ( If you wish you can contribute to my code, I will be very thankful for that.

But now let`s see the basic functionality of the code.

Loading Symfony HttpFoundation and HttpKernel for managing requests and routing, run the business logic than pass the result to a render engine. For templating I used Twig, because this is the template engine I like the most and also because it is one of the best template engines available I know about.

So the most basic usage of the framework is the following. You map your routes in the routes/routing.php file, in the method called routes():

$app->map(‘/map/your/route/{and_also_variable}’, function ($name) {

global $twig;

$oldal = $twig->render(‘index.html‘, array(‘variable1’ => ‘value1’, ….));

return new Response( $oldal ); (= “oldal” means page, it`s in Hungarian and will be fixed later)

The render method takes to arguments. The first is index. html the name of the template we want to render, these have to be placed inside the view folder and can be grouped in folders. The second is an array, here you can pass the results the controller generated. Controllers can be placed inside controllers folder, and an instance of them can be created using a kernel method called loadController(“controller_name”).

Basically that would be my micro php framework, but this is just an alfa version, later (in the near future) I will make some improvements, just follow my repo on Github.


Cheap but usefull PCB drill from broken electronics

In my opinion our society is built upon wasting. Buy, use than throw away. Every year million tons of harmful trash is thrown away or in better cases recycled. But even when recycling the raw materials are reached out of them, the finished product is destroyed. Of course in industrial sizes this is the most efficient and only way of doing it.

As a student I can`t afford buying expensive tools for my hobby projects. For example, what about this post will tell, a small PCB drill which cost up to 15-25$ if bought from a store. So if it is possible I make my own tools. In this post I am going to talk about a small, inexpensive PCB drill with changeable drill bits. Building this thing cost me about $1,5 and half an hour. It can run from a 12V and 2 amps power supply.

Here is the parts list:

  1. 1 x small 12v dc motor taken from a broken hairdryer
  2. 1 x small switch from a dead microwave owen
  3. pair of cables left from an old ATX – yellow and black
  4. some solder
  5. zip ties
  6. insulating tape
  7. DC jack
  8. old battery charger that can output from x volts to 12v and around 2 amps

This is how it looks in action:

The momentary switch was taped around the motor and the wires soldered to the terminals, at the other and of the cable there is a jack which helps connecting the drill to the power supply. On the rod of the motor there is a mount in which are placed the drill bits. The only things I had to buy were the drill bit mounting and the small drill bits.

When the drill was finished the testing phase was the next. I made small holes in things laying around my table, including two of my fingers. I had 3 types of drill bits for wood, it worked best with the smallest which is around 1 mm wide. I tried it on several surfaces like wood, plastic and of course on a PCB. Of course, it went through on anything even on thin copper.

The drill draws around 0.3 amps without load at 12 v, and around 1.5-2 amps when drilling depending on the hardness of the surface.