Introduction: Android-based Vintage Radio

I have re-built a vintage radio. The device is be able to play music and download daily news podcast.

I have used an Android tablet as a base, STA540 for an amplifier, Blaupunkt GTx-542 speakers and, of course, an awesome vintage radio case.

Here is a video that demonstrates how it all works together:



This instructable tells about how the gadget was created.

Step 1: Device's Components

Here are components I've chosen to use for this project:

Vintage radio for project enclosure. eBay has plenty of old radios. Some are fully operational, some have seen their better days. I've picked one that did not work, but had its body in a good condition.

One might ask: why not restore the old radio? This might certainly be very exciting project. Unfortunately I am not very experienced with vacuum tubes. Also, I am not a big fan of non-customizable radio stations. 

One might ask: what did you do with the old components? I still have them. I have no idea which are in working condition. If you want them and ready to pay postage – shoot me a message.

Archos 28 as base. Archos 28 is a reasonably priced (~80$) Android device that has all the features I need: 8Gb of internal memory, Wi-Fi, microphone and audio out. I have used it in my previous project and it has proven to be a very reliable gadget: it has worked 24/7 for the last 3 months. 

One might ask: why not use a microcontroller and a set of chips? It looked a bit simpler and more efficient to use Archos 28, as it has all components on its board and also comes with OS Android. Since my radio is expected to be plugged in all the time, so power consumption is not an issue.

IOIO Board to interact with hardware. IOIO Board is an amazing device: it plugs into Android device via USB. Android device discovers it as an ADB host. There is a nice little API that allows any Android application read line state (either digitally or do analog read) and generate either digital or PWM signal on a line.

One might ask: why not use Android ADK? Unfortunately, ADK has been added only in Android 2.3. Archos 28 is running 2.2.

STA540 as an amplifier. I am not an expert in audio devices. I've picked this particular model because of many positive reviews by fellow DIYers. STA540 is a 4-channel, class AB audio amplifier. It has a really nice standby mode: it is exceptionally quite.

Blaupunkt GTx-542. These 4Ohm, 70-20,000 Hz, 2-Way coaxial speakers had a right size and a right price. 

One might ask: why not some other speakers? I would shrug my shoulders: if you have any other speakers that fit this device better, please leave comment.

Misc. I've also used a rotary encoder to change songs, four buttons for changing stations and a bunch of capacitors, diodes and resistors to bring it all together.   

Step 2: Preparation

Remove old components. Since I didn't plan to reuse most of the old components, they had to go. I could see at least two generations of engineers working on this radio before me.

Prepare chassis. I decided to use a PCB base board to put all my circuits on. This base would attach directly to the original metal chassis of the radio. I've used Dremel tool to cut the board.

Prepare body. The only modification I had to make is a cut a little niche to fit Archos 28 into the body. I've used Dremel tool to do that.


Step 3: Software

There was nothing awfully complicated about device's software. An Android app controls device's lifecyle: it uses IOIO board to read  hardware state and play proper song from the SD-card.

Screen. I guess the most interesting part was designing application UI. I really wanted it to have the same style as the rest of the device. I had following mental model in mind: four adjacent cylinders represent four stations. Each cylinder contains song names on it. Only one cylinder is visible at a time. A knob on the right rotates visible cylinder thus changing a song. Pressing a button under the display changes cylinder thus chaining an active station. Stations are just folders on tablet's SD-card.

Podcast. Since I wanted to be able to listen to an only one news podcast (namely, BBC Global News) my podcast support was quite trivial: a thread wakes up every once in a while, reads podcast XML, downloads newest podcast MP3 and places it in the "News" folder. 

FTP Server. I plan to include a little FTP server into the next version of the app. It would be really nice to be able to upload musing wirelessly. Since the device is already connected to my home Wi-Fi, it should be quite easy to transfer data back and forth.

Device's source code is available at google code.

Step 4: Circuit

Making the circuit work was the most time consuming part. Although it was easy to put all components together, it took me forever to figure out why a speaker is producing a constant 80Hz humming noise. I've made there are no loose wires, all critical wires are shielded and player's output is clean. Then I found that the problem was a bad power supply. Sparkfun 12V adapter is not a good component for this application. Enercell 9V adapter showed to be much better choice.

Step 5: Result

My radio plays music, downloads podcasts and looks vintage & high-tech. This project was also a lot of fun to work on: writing Android app, working on wood, hacking together a circuit, Photoshoping (rather, Pixelmatoring) device's screen and, of course, trying to be true to radio's original nature.

I would love to hear any comments or suggestions!

Comments

author
pete.spaker made it!(author)2015-05-20

Nice man. I make these all the time. Usually bluetooth. That radio is quite the find. I do the exact same thing- eBay for the "not working / for parts" vintagge radios. I have more of them than I know what to do with at this point. Something cool to do is throw a RasPi in one running "Zune." You can navigate it from any browser (like a phone). But I love the 4 buttons and the news station. I'm for sure doing that in the future.

author
sstorkel made it!(author)2013-12-29

Cool project! An explanation of the way you wired the various electronic components together would make it even more useful...

author
Sement made it!(author)2013-12-18

Nice project! I have in my mind an WiFi radio based on Archos 28 for 2 years. And you made it!

author
SparkyOR made it!(author)2013-09-28

It's the "Misc" part that I'm interested in.

author
robot797 made it!(author)2012-01-14

i realy want to hit you for killing a great radio

so here it is "BAM"

now to say

nice work

what did you do with the tubes?

author
basil.shikin made it!(author)2012-01-14

Well, I didn't quite kill it: it was dead on arrival. It would be to painful to take apart a working radio.

As for tubes & components, I've sent them to someone who is into restoration of old radios. I hope he will find good use to them.

author
TheRealDutchOwner made it!(author)2012-09-02

Hats off to you sir. Great that you spared the tubes and components, because this radio might be dead, but another one could be saved by the parts. Just like an organ donor :)

author
mpep made it!(author)2012-01-07

A job well done.
Switch Mode Power Supplies are NOT good options for audio work! But I guess you found that out already ;-).

author
sconner1 made it!(author)2011-12-12

I had that very same meter until I accidentally fried it.

author
x7319808 made it!(author)2011-12-11

Sir I have a 50's tube radio that I found while stationed in Karlsruhe FRG in the late 70's. I rebuilt it from spare parts so it is a Frankenstien model but the blasted thing plays well.
You did an excellent rebuild.

author
Penolopy+Bulnick made it!(author)2011-11-29

Awesome!  I love the vintage look!

author
basil.shikin made it!(author)2011-11-29

Thank you. I have tired hard to preseve original style of the device. There is something about that art deco-ish look that one might find really attractive.

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