The idea was to recycle a old Video station not anymore used to create the following features:
- recharger station for 6 different devices - iphone - ipads - Nokia phones
- Audio amplifier to connect one of the iphones and listen internet radio or own music
- Raspberry PI media center
so that the media center will provide provide video - audio - internet radio - recharge phones.
The other objective was to keep the budget as low as possible so I recycled everything I could.
At the beginning I was thinking to buy discrete components and to solder them. After a few researches I understood that everything was already available at cheap price (few EUROs) so that I decided to assemble them
Step 1: Elements for Power Supply
One by one:
- Power supply (not in photo): I bought a power supply for amazon 12V 5A (60W) at about 12 EUR. 12V were needed both for the 5V supply (see later) and for the audio amplifier.
- 5V supply: I used the lighter plugs you can see in the photos. they provide 5V 1A and you can use them in your car. why not use them at home?
- plug for 5V supply: I bought a couple of supports for the plugs so that I can use multiple plugs at a time. One of them will be used to supply the raspberry and will be kept internal to the chassis, the other will be used outside.
The element with 3 slots and the 5V supplies with 2 outputs I can charge 7 phones at the same time. Let's make some calculation: 7 devices x 5 V x 1A = 35W. I'm already using half of the power of the 12V power supply. the remaining (25W) will be used by the audio amplifier
Step 2: Audio Section
I found a D class audio amplifier for 4.95EUR on ebay. Pay attention the very same audio amplifier costs about 18 EUR on Amazon. I choose that one because of the price. I want to keep all the stuff as cheap as possible. you can use better amplifier if you want.
I added the cable for the iphone - ipad that has two exits: the normal USB plug for recharge and the Jack audio plug to connect it to the amplifier. In this way you just need to connect one cable to recharge and listen to music/internet radio.
I preferred this solution to a bluetooth dongle (there are some available for about 6 EUR as the one shown in the page) because I do not like too much things emitting microwaves in my house. You can of course use one of these if you prefer. and more than that you can add a 2 ways selector to select between multiple inputs to feed the audio amplifier. Of course if you use a dongle you need an additional 5V USB plug inside and you can connect it directly to the audio amplifier. If you use a non metallic chassis the dongle can stay inside and disappear!
Step 3: Put All Togheter
so I opened the old chassis, removed all the unneeded stuff and connected my elements as a Lego game.
So one plug contains the USB power supply (on the right) and I used both outputs of 5V 1A to feed the raspberry to be sure about the voltage. I added a switch (upper right) to command the power supply for the raspberry as I do not want to keep it always on.
The rack for the plugs is behind (above in the photo) so that I can use the 7 outputs to recharge all my devices
On the bottom (front of the chassis) I recycled a old USB speaker circuit. I kept just the switch, the LED and the input for the Audio Jack. So that I can connect everything from outside and switch the amplifier on/off.
In future I may use a 2 ways selector to select multiple inputs for the audio amplifier (above) such as the bluetooth dongle, the external cable (coming from a device) the raspberry Pi audio output, any other audio source I may have.
Step 4: Assembling
in the above photos you can see the front and the back of the chassis before closing it.
I had to dremel a bit the plastic walls but the final result was not so bad. Also the front with the Audio connector and the button is not destroyed. I tried to keep all that I could on the backnot to have a bad looking in front.
Regarding Raspberry Pi, there are many instructables to customize it. I used Raspbmc and I can use the little tool as a mediacenter, as a NAS and with many other features.