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Author: Silveira

Hi, I'm a developer, lover of art and freedom (more). I write mostly about technology and pixel art.

Governo militar

Os números já estão sendo torturados. O regime já está matando. Os mortos estão desaparecendo. Há ditaduras militares com menos militares que o governo atual do Brasil.

O Ministério da Saúde ocupado por um militar sem qualificação nenhuma na área-fim da pasta [1]. No restante da pasta mais 25 militares até agora [2]. O restante do executivo não está diferente. O presidente, capitão bunda-suja, o vice, um general. Ministros militares são nove. 3 mil militares da ativa e reserva no restante do executivo[3]. Isso sem contar os casos claros de nepotismo como os filhos do presidente [4] e do vice presidente [5] e base-se lá quantos mais familiares e amigos desses outros 3 mil.

[1] O Ministério da Saúde sob intervenção militar – El País.

[2] Ministério da Saúde chega a 25 militares nomeados – Estado de Minas.,1154152/ministerio-da-saude-chega-a-25-militares-nomeados.shtml

[3] Cúpula militar se afasta de radicalismo de Bolsonaro, mas estudiosos veem risco entre oficiais de média e baixa patente – BBC Brasil.

[4] ‘Já botei parentes no passado, sim. Qual é o problema?’, diz Bolsonaro – O Globo.

[5] Mourão diz que filho tem ‘mérito’; indicação não viola regra de nepotismo – Exame.

Python: Getting page title

# Get the HTML page content
from urllib import request
html = request.urlopen("").read()

# Get the title tag
from bs4 import BeautifulSoup
title = BeautifulSoup(html, 'html.parser').find('title')


This uses the XML/HTML library BeautifulSoup . This could also be done using regex but playing with HTML and regex is usually a bad idea.

Mortal Kombat Arcade Cabinet from Arcade1UP – Part 4: Sound and lights

Check out the all parts of the Mortal Kombat Arcade Cabinet from Arcade1UP serie:


The great ETA PRIME’s ‪Arcade1UP Raspberry Pi Install Tutorial – RetroPie in an Arcade1UP video tutorial uses an amplifier and speakers. That’s a great solution and probably what you need. As I said before a lot of the decisions I’ve made were based of things I already had around at home.

For instance, I had an Cyber Acoustics CA-3602FFP 2.1 Speaker Sound System with Subwoofer and Control Pod around without use after I upgraded some equipment100. I’m not going to disagree with anyone who says this is a total overkill for this project. This has a lot of power and a subwoofer. It greatly exceeds the sound needs for old arcades games. However, it was literally accumulating dust in a corner.

Cyber Acoustics CA-3602FFP 2.1 Speaker Sound System with Subwoofer and Control Pod

This thing also have this little control pod that is just perfect for this project. It controls the volume using a knob. I absolutely love control knobs. I could write a whole post about knobs. It has a round blue led which goes well with the whole arcade theme. On top of all that, the control pod also has a control for bass, an on/off switch, an auxiliary input and a phone output.

Volume control

Because the wires fit in the gap between the panels no drilling was necessary. Inside the cabinet I just put the subwoofer an the two speakers. I used a double-sided mounting tape to put it in place.

The little blue circle light.

For the sound input I used the sound output from the control board. That is already converting the HDMI sound output. Another solution would be to plug it directly into the Raspberry PI and configure it to output the sound there instead of sending it via HDMI.

Control board to speakers


The last thing I added was just some LED strip lights in the back of the machine. It’s just some led multicolor strip lights that I bough a while ago for around 5 bucks. I just let it set to red because it goes well with the vinyl strip it came with.

Really ties the room together.

That’s probably the simplest and cheapest of all the modifications but really adds some ambiance around the cabinet.

Because the lights and everything else are in the same power strip that is behind the same Amazon Smart Plug when I say “alexa turn the arcade on” everything lights up with a lot of colors.


This has been a long and fun project. I have been incrementallychanging parts and adding modifications. It’s slow and it’s not a single weekend project. It’s good to spend time on each iteration and getting a felling of what needs to be improved. There is still some room for a few more lights and maybe a beer holder. Other than that the next changes should be on software.

Mortal Kombat Arcade Cabinet from Arcade1UP – Part 3: More buttons

Check out the all parts of the Mortal Kombat Arcade Cabinet from Arcade1UP serie:

I decided to add a second control deck to this cabinet using the wood panel that already came with the original machine. My initial plan was to add 4 more buttons so each player would have 2 extra buttons for games that requires a lot of buttons.


Before committing to a layout and irreversible woodworking I build a crude but functional prototype out of cardboard.

Cardboard prototype

The prototype was important to realize this was not the layout I wanted. I wanted more buttons. The original control deck has 7 buttons for each of the 2 players. Usually this would be enough but you have to use one of them to the start button and another for coin button. You also need a special button to exit the emulator. That’s 3 out of 7 buttons. Only 4 left for the core gameplay itself. Because this machine should be generic for many types of games I decided to add 3 more buttons for each player so each player has a total of 10 buttons.

The cardboard prototype is an optional step but it was easy and quick to do, it’s fully functional, and provided me some insights for the next steps. I used a piece of cardboard and put the panel J to trace a copy over it using a pencil. Then I cut the cardboard using a craft knife and also cut holes for the buttons. I installed it i the buttons, put the cardboard in the same place of the Panel J, put the wires, and configured the software. I could use the machine like this for some weeks before I moved to the next phase.


I don’t have a lot of experience with wood so this was my attempt. I had this piece of black coated plywood (45.72 x 17.78 cm ~ 18 x 7 inches) and I wanted to put 6 arcade buttons on it.

46 cm x 18 cm (18 inches x 7 inches)

First I needed a layout for the buttons. By using the prototype for a while I wanted the buttons in the middle of the panel. Some margin from the sides. Some space in the middle for some future project. The method I used to make the lines using a mechanical paper and a rule is the following:

  • First, I measure the number I want on one side. Here, I wanted a straight line in the middle of the panel. I get the height of the panel (7 inches ~ 17.78 cm) divide it by 2 (3 ½ inches ~ 8.89 cm) and mark it down using a mechanical pencil.
  • Second, I do the same thing in the opposite side of the panel.
  • Third, I trace a line between those two points. As I don’t have a rule long enough for this line I used a metal tape measure. Any long straight object will do.
Because I was using a tape measure I used tape to fix it on both side before making the line.

Now repeating this process I got a perpendicular line in the middle of the panel. Then other 2 lines each 1 each away from the border.

Then I did moved another 1 inch to mark where the first button was going to be. This way the first button center is 2 inches away from the border. From this center I moved 2 more inches to find the next center. And then did the same for third center. I repeated the same process for the second player.

I happen to have this circles template that is very handy here. The circle I need is 1 ⅛ ” (2.8575 cm) and I could use the template to test if the button fits before committing to the whole size. It fits perfectly. This is the same whole size for the other buttons in this Arcade1Up.

Using red graphite and the circles template I made the circles where the buttons would be. This step is not really necessary but I wanted to be sure this looks okay before doing the holes.


I put a old piece of wood bellow the panel I’m going to drill. This way when I go over the panel I will not hit the table. I’m using a 1 ⅛ ” spade drill from this drill bit set and a Black & Decker LD120VA drill.

Point of no return on this project.
Oh, there is a lot of sawdust. Better do this outside.
6 buttons. 6 holes.

On one side the wholes where clean but in the other side there were these ugly “exit wounds”. As I said, I don’t have a lot of experience with wood. Fortunately this board is the same both sides and I could just clean the side that was supposed to be hidden and use as a front panel.

How could I have avoided this?


Buttons installation is just like it was on part 2. In total I could use all the buttons that came with the kit.

6 more buttons

They are close enough from the control board so the wires can reach the connectors. Here I’m glad I did the cardboard prototype because I knew I didn’t need to extend these wires.

No cable management.

As far as configurations go it is the same as in part 2. These buttons behave just like any of the other buttons. For the Raspberry PI this is a computer with two USB joysticks plugged on it. Each with 10 buttons and the directional which is the same as another 4 buttons.

Everything lit.


Now this machine has two joysticks and 20 buttons and 2 joysticks. That is enough to play all the games I want. On the next part of this tutorial I will show how to add better sound and even more lights.

Mortal Kombat Arcade Cabinet from Arcade1UP – Part 2: Raspberry PI and custom buttons and joystick

Check out the all parts of the Mortal Kombat Arcade Cabinet from Arcade1UP serie:

Previously I showed the Mortal Kombat Arcade Cabinet from Arcade1UP – Part 1: out of the box. Now I’m showing how to modify it with a Raspberry PI so it can play a full set of arcade games. I’m also replacing the original buttons and joysticks.

I would like to thank and recommend the ETA PRIME’s ‪Arcade1UP Raspberry Pi Install Tutorial – RetroPie in an Arcade1UP video. I’m following almost the same steps and parts but adapting a few things to use equipment I already had or to suit my personal preferences.

Architecture Diagram

What I’m showing here was done with an Arcade1UP Mortal Kombat but should work for other models with little changes. One of the reasons I choose the Mortal Kombat cabinet was because the number of buttons and their layout.

Parts used

It’s worth noticing that you don’t necessarily need all these parts or these parts in specific. These were the ones I used and most of them were not bought specifically for this project and I could use them because I had around.

Replacing the joysticks and buttons

The original buttons on my MK Arcade1Up were a bit ugly and quiet. I want something more flashy and more clickly. I went with this kit on eBay that comes with 20 buttons, joysticks and encoders. The buttons have a LED inside and a round plastic chrome ring around them. They also come with everything necessary to replace the original buttons and they fit in the same 1 ⅛ ” (2.8575 cm) hole.

Old buttons.
New buttons

Step 1. Remove the control deck from the cabinet.

Control deck detached from cabinet

Step 2. Remove the protective black plastic case exposing the wires and circuit boards from the control deck.

Control deck with protection case removed
Original control deck components

Step 3. Remove all the wires.

Wires removed

Step 4. Remove the buttons. They are a single piece. You just have to press them in their opposite bulges and they will fit to leave the hole in the front panel.

… and push.
Old buttons removed

Step 5. Remove the controller board. Just unscrew it and remove it.

Step 6. Remove the old joysticks. First unscrew the bat top of both joysticks. Remove the screws that connect the metal plate to the board. The metal place is also glued to the board. You need to melt the glue a little so you can pry out these panels out. Here you can use a heat gun or a hair drier.

Blow some hot air directly in the metal panel. The smell of the carcinogenic fumes you are breathing means the glue is now melting.

I would recommend this step in a well ventilated area.

Use a knife or a screwdriver to pry out the metal plate. You can heat a little and pry a little until the whole plate is out.

Melt the glue and pry it out.

For now I’m not removing the speaker and switches.

Control deck after I removed the buttons and joysticks.
Everything I removed from the control deck so far.

Step 7. Install the new buttons. These buttons are a little bit different from the original ones. They have two pieces, the mechanical part and the connectors and LED. You can separate them by twisting. They also have a plastic nut that help fix them to the board.

New button, side view.
News button, top view.

At this step you have the option to choose the color schema for your buttons. I choose something symmetrical. The button assignment is done later in software.

Step 8: Install the joysticks. Remove the bat top from the joystick. Insert it into the panel. Put the screws.

Buttons and joysticks installed

Step 9. Mount the USB control boards. I used Scotch Permanent Mounting Tape for this. Little screws would also do the job. When choosing where to mount them keep in mind the distance between the board and the buttons and also the USB wires.

Boards installed.

Step 10. Assemble the other end of the buttons. Just twist them in place.

Buttons assembled.

Step 11. Install the wires. Each button will expose four connectors. Check your manual for the proper color schema for the wires. They are different depending on the kit you choose and the kit you get.

The order that you put the connectors in the board is not really important because the configuration will be done later in software.

Step 12. Screw the joystick handle back. You can use the new joystick handle but can reuse the old one as well. The new joystick came with a balltop handle (left) and the original joystick had a battop handle. The handle is fixed screwing. You can easily change it latter without need of any tools.

Blue balltop handle (left) in the new joystick and the original joystick with a red battop handle.

Step 13. Testing everything. I this point I would recommend putting the protective plastic case back but secured by only a few screws because you will very likely reopen it soon to fix some buttons.

Plug the two USB cables from the encoding boards to a computer.

The first test is to check if the lights. If a light is not on it is probably because the wires are not correctly connected. If it is not that, then the LED could be failing. My kit came with some extra LEDs and components (but it was not necessary so far).

You can also test the whole control deck as two completely functional controls with the PC. Windows should auto-detect the boards as two USB joysticks.

USB Joystick configuration screen.
Control deck playing Ultra Street Fighter IV on a PC

Installing the controller board

The original monitor from an Arcade1UP cannot be directly used with a video cable like HDMI. I’m using this kit for this. Make sure the code in the back of the Arcade1UP monitor matches the one in the description of the product.

Step 1. Remove the metal box case with the original board from the monitor. This case holds the mother board of the original Arcade1UP. Remove the cables and remove it from the cabinet.

The heart of the MK Arcade1UP.

Step 2. Install the new board. I put some tape in the back metal panel of the monitor and used double face tape to fix the new controller board.

The power supply is the same from the original board. This board now receives a video input (HDMI, VGA, VGI) and displays it in the monitor. The smaller board with 6 buttons are like buttons in a TV where you can change volume, brightness, etc.

Step 3. Test you can display external video in this monitor. Just grab an HDMI cable from your PC and plug into the controller board. It should just display it like an external monitor.

Arcade1UP monitor connected from the PC

Installing the Raspberry Pi

A Raspberry Pi is pretty much a tiny Linux computer. It has everything on a single package (memory, CPU, motherboard, etc). I’m using RetroPie as a distribution. Retropie comes with everything you need but the actual game ROMs.

Raspberry Pi 3 Model B

When I was building this I noticed that the Raspberry Pi 3 had the best compatibility and was working well with most of emulators and games. This is likely changing in the future so if I was building another machine now I would check this again. I already had a RPi 3B with a case (Kintaro Super Kuma) from another project.

Raspberry PI with a SNES inspired case

For now I’m not going to put here fine grained details on the RPi installation and configuration. In short, you need to download RetroPie, make a bootable SD card with it, stick it into the RPi and boot it. There are many ways to add games but the most practical one I found was via network using SMB (Samba). Making sure the files are in the correct folders for each emulator. For example rooms for Game Boy should be at “/home/pi/RetroPie/roms/gb/” and for Neo Geo at “/home/pi/RetroPie/roms/neogeo/”.

Raspberry Pi booting with Retro Pi

To make the whole process easier I highly recommend using a wireless keyboard like the Logitech K400 Plus that already comes with a touchpad. It’s small, takes only a USB slot and is great keyboard to have around for projects like this. You can press Ctrl + Alt + F2 to access the Raspberry pi terminal (F3 to F6 for TTY3 to TTY6 respectively). Retropie default user is pi and default password is raspberry.

Light up marquee working.
Logitech K400+

I done my first test with the Game Boy emulator and Kid Dracula. After that worked I moved to test more games.

Kid Dracula. Game Boy, 1993.

When I moved to games with a little bit heavier emulation I started to get this error.

under-voltage detected

The documentation for this said “The undervoltage icon is displayed when the voltage the Pi is receiving drops below 4.65V. “. Indeed, I was using a common USB charger. I then moved to a dedicated charger designed for a RPi that could provide enough current and voltage to power the RPi.

Sound system

I had some Cyber Acoustics CA-3602FFP 2.1 Speaker Sound System with Subwoofer around that I used here. They are definitively an overkill for this project but I had them around and this could save me the trouble of dealing with amplifiers.

Cyber Acoustics speakers

Light Up Marquee

In the original light up marquee was powered by the output of the main board. The original power supply now powers the monitor controller board. I used this splitter cable to send one cable to the controller board and the other the the light up marquee. It’s always worth checking the polarity and voltage of these things.

Testing voltage and polarity.

Because the splitter outputs two jack cables (male) and the lightup marquee cable is also a jack I had to do this workaround to connect the two cables. Cutting and reconnecting the cables would also work but I did not want to do that to the marquee cable. Later I will fix this.

“Nothing is more permanent than a temporary solution”, old Russian proverb.
All working.

Alexa integration

In front of all this I’m using an Amazon Smart Plug so I can say “Alexa, turn the arcade on” and everything is powered with all the lights and sounds. Other people have reused the on/off switch from the original control deck for this.


At this point this arcade cabinet is fully functional and can play hundreds of games. I’m still doing further modifications and improvements but they will come in future posts.