Hello, my name is Daniel, and I make things! Join me in this exciting journey exploring the world of computers and electronics

AD5204 Digital Potentiometer Breakout Board


The AD5204 is a Digital Potentiometer with four internal 10kΩ, 50kΩ or 100kΩ potentiometers. It’s a 8 bits chip which means it has 2^8 = 256 steps from 0Ω to 100kΩ. It can be easily controlled by any microcontroller as it uses a Serial Peripheral Interface Bus (SPI).

I was working on a project where I needed to use some of those AD5204, so I developed a tiny breakout board in order to be able to prototype it using a SMD chip on the breadboard.

Now I’m sharing the Eagle Cad files, so whenever you need to use this chip, you can make some breakout boards with OSH PARK and use it with your projects.

Below you can find an Arduino code example along with useful links.
Hope this can be useful for you!

Any question just let me know!

Raspberry Pi Using Whole SD Card Memory

When you install a Raspbian Operation System on your Raspberry Pi (I’m currently using Minibian) you can notice that it created a file system with very little space, which can be annoying if you are using a bigger SD card.

I only noticed it when I started to apt-get all those packages that I needed, when suddenly got the message:

cannot copy extracted data for './usr/sbin/php5-fpm' to '/usr/sbin/php5-fpm.dpkg-new': failed to write (No space left on device)

Looking into the SD card’s memory I get:

It’s full!!

BarTop Mame Cabinet (under dev)

Who hasn’t spend a lot of money and time on arcades during childhood? What about build one and play all those games again?

Mame Cabinet

Browsing the web I found that a lot of people are building their own machines, building over a pc running a MAME emulator with a cool front-end. If you google images for ‘arcade cabinet‘ you will be amazed by what people are doing!!

I decided then to build my own, trying to use as much used stuff as possible, like a old computer, old screen and two usb game controllers that were broken but with the electronics hardware in perfect conditions. The cabinet will stay on the hackerspace from my town, TARRAFA HACKERSPACE, so we can set some championships, it will be fun for sure!!!

On this post, I will be giving updates on the progress (not much will be done during university semester, I hope to finish this project on holidays).

ATmega8A Development Kit Review

Few days ago I received a ATmega8A Development Kit from ProtoStack.

The board is well made, and it has everything you need to start developing any kind of project using the famous Atmega8, which is the same µC used by the first Arduino. Actually, you can also use this board with different µC’s such as Atmega168 and Atmega328 (used in Arduino UNO).

The kit have a lot of space to add more components, and a good thing is that the VCC and GND voltage is easily accessed everywhere of the board. On the pictures and the video I posted here, I have connected the output pin PB2 to an resistor, green LED and to the ground, even without soldering the board works great.

Open Source Hardware Association

Just want to share this cool Association that is being created:

The Open Source Hardware Association is Coming Soon! It will be a non-profit organization (status pending) working to spread the love of open source hardware. We’re working out details, and as soon as we know, you’ll know! Check back at oshwa.org for upcoming news.

They are asking people to fill a survey so they can know which path follow to make the association. You can help them by filling it here: http://www.surveymonkey.com/s/OSHW


Back in 2003, I used to connect my computer on the my old 32′ TV, those huge and heavy TVs, to watch stuff from the internet, at that time, eMule was ruling the p2p community (can’t talk about USENET right? :} ). Then in 2008 I decided to build a better HTPC (Home Theater PC), a full dedicated computer connected to my TV, with good MotherBoard/VGA/SoundBoard, well, a good computer, with gaming capacities. It was good while it lasted, but you know, it was huge black box below my TV, bit noisy, but it did the job.

Dotklok + LM35 Temperature Sensor

I got my Dotklok up and running some days ago, I am really enjoying it on my room.
But I want to do more with it. Too bad right now I don’t have much time to play with electronics and build cool things.

Anyway, today I decided to spend some time learning the Dotklok’s code and add a temperature sensor to it. The result was really cool, and now I am sharing the bit of code I added to the clock.

Arduino + Sound Sensor

I got a sound sensor on Ebay some days ago, and decided to give it a try!
Really simple, just made a code to light up the led when the volume was higher than the ambient sound.

Just for fun! 😉

As many people have asked, here goes the code:

Remember that there are many other ways of doing this, for example using the PWM function along with analogRead() and map().

Using Arduino to calculate Quadratic function

This is a simple and quick code I made for teach variables with arduino programming,
where we enter the variable numbers a, b, c in

and we get the answer using the Serial Monitor..

I won’t get in details about this code, it’s quite straightforward. But if you have any question, just ask! 🙂

My HTPC 2.0

Long ago, I wrote How I Made my HTPC at my place. Time passes and things change. End of year has arrived, Christmas and everything, so I decided to upgrade my system to a more efficient and cheaper one. The new choices were using a NAS (Network Attached Storage) allowing all files can be accessed from any machine connected to the network, in this case I am using Lacie Network Space 2 2TB storage. A Gigabit router TP-LINK , so far I’m very happy with this router, although. A media player WD-PLUS Live that has an embedded Linux and play videos in various formats, even FullHD , and access online content like YouTube and some radios.