Blog - Sketching with Hardware

Team 1 – Berni the Boombox – Technical Documentation

Published on: | Author: Patrick Suchostawski | Categories: 2017b, Projects

From old to new

At first we started gathering ideas for turning an old object into a fancy new device with as many functions as possible. After we decided to take an old CD-Player for this project to turn it into something special we met many restrictions at this point. First we wanted to create a CD-Player that plays different web-radio streams, but due to the Ethernet connection in our building, we accepted our fate that this won’t be possible. Many other features we thought of had also to be discarded due to time issues. At least we decided to create a CD-Player that plays several pieces of music, while the original speaker recess gets a new functionality: Showing an eye-like LED panel with several eyeforms fitting the music it plays.


Inside the Player

This radio contains a soundmodule and a Neopixel-strip for the eyes of the player. We also used the buttons of the player itself to change the songs and the eyes given. So we created a CD-Player alike behaviour when using this device. The amplifier we used for the speakers had also enough space in this case. All requirements for a good project were given.


What parts we used

  • 1 x Arduino Uno
  • 1 x wtv020 Soundmodule
  • 1 x 2GB SD-Card
  • 1 x 12V power-supply
  • 1 x 5V USB charger
  • 1 x Original CD-Player speakers (Sony)
  • 3 x Original CD-Player buttons
  • 1 x 10kΩ Potentiometer
  • 1 x 100Ω Resistor
  • 1 x 1000µF Capacitor



First of all we Connected the Neopixel-eyes to the Arduino to check whether they work. The sound module works separately to the Arduino Uno, so we wanted to make sure they work properly. They are connected to a digital pin, so that each LED of the pixelstrip can be manipulated separately. After that we checked the speaker and the amplifier for their functionality. It is important, that the ground of the 12V power supply isn’t connected to the ground of the 5V Arduino power supply! After several tries we managed to play Tetris music on the speaker. A first big step was made. Now let’s start with the sound module. After losing nearly 10 hours or even more to run the sound module properly, we are pretty proud of the fact that we finally did it. There were so many we’ve been trying of connecting it and play some sounds that were given on a website, but it never worked the way we wanted it to work. We realized that this module can only read a 2GB micro-SD card and everything above this size won’t work. Another struggle was the conversion of the sound file, because this module only reads a special audioformat called ‘.ad4’. The conversion can be done via console command that uses a script to convert a 16-Bit, 36kHz PCM Wave file into a .ad4 file or a mac program to convert a mp3 into ad4. This whole process of playing music on that CD-Player was very time intense, but worth the anger. Right after, we silenced the speaker with a potentiometer, due to that massive output it had. Last of all we connected the buttons of the ghetto blaster to give the listener a well known feeling while clicking through the songs. We were told to use a capacitor to compensate any voltage differences that could occure.

We even worked out a ermergency plan, that if nothing worked, we would have played Tetris music, where the speed could be changed via a potentiometer, while the eyes change depending on the actual speed of the music.

(In this picture the sound module has 18 Pins, so very left pins were not present on the module itself, so if you have a 16-pin sound module, just read from right to left)





The code includes the inputs of all three buttons and the animation of the eyes, as well as their changing. It should be well documented.

Feel free to use and modify the code. It can be seen right here:


The final result

Doesn’t it look adorable?



linked categories 2017b, Projects


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