Radio's Next Generation: Radii

See how Linux can be used to prototype a sophisticated Internet appliance.

A phrase we heard many times when we sought venture capital to develop the Internet appliance we call Radii was “If this were 1999, you would already have your money.” Unfortunately, it was 2004 and there was no money for a risky consumer product such as Radii, despite our compelling prototype and a well-defined market. Rather than let our efforts go to waste, we decided to share the details of the prototype here with the Linux community that made its development possible. In this article, we explain how we quickly built our Radii prototype using low-cost hardware and Linux along with some of its companion software, including Perl and GCC.

Figure 1. Radii—a 1950s-style radio with Internet content.

Radii is a radio: a box with buttons and dials used to select bands and tune stations in a familiar way. Because this radio receives Internet radio, it provides hundreds of noise-free stations with a wide variety of listening options. The band selection dial, instead of AM and FM, is used to select genres such as News, Sports and Rock. The station selection dial scrolls through station names that can be tuned by clicking the select button.

At the beginning of this project, the three of us threw in $100 each and some spare time while continuing to work our day jobs. We never thought of this as an exercise in rapid prototyping; it was all about implementing our vision as quickly and inexpensively as possible. At every step of our development, we looked for the fastest way to get the task accomplished and balanced that against its cost.

The prototype is housed in a converted SW-54 radio made by the National Radio Company in the 1950s. The radio was in poor condition before the conversion. As admirers and collectors of old technology, we like to think we gave it a new lease on life.

Hardware Overview

The Radii core hardware platform is an old laptop running Linux. The operator interface consists of two rotary encoders, three momentary contact buttons, a 40x2 backlit LCD, a power supply and a retro radio cabinet. The encoders and buttons are connected to a PIC microcontroller development board that is, in turn, connected to the laptop's serial port. The LCD is connected to the laptop's parallel port.

On our budget of $300, cost was important. As such, eBay was our vendor of choice. Here is our hardware shopping list:

  • PIC microcontroller dev board (OOPIC) ($70).

  • One TTL to RS-232 chip (TI MAX232) and associated bits to interface the PIC to RS-232 ($5).

  • Three momentary buttons for selection/special functions ($3).

  • Two rotary encoders one for band selection, one for stations selection ($3).

  • One 40x2 LED backlit LCD ($12 eBay).

  • Gateway Solo 5150, 300MHz Pentium laptop, broken screen ($100 eBay).

  • One National NC-54 vintage radio ($35 eBay).

  • Power supply for PIC and LCD (3/$10 eBay).

  • Cables, connectors, bubble gum, baling wire and so on. ($25).

  • Shipping, fees and taxes took up most of the remaining funds.

A PIC microcontroller is a single-chip computer produced by Microchip Technology, Inc. Although these tiny computers are capable of many useful things, we used it here simply to handle operator inputs. For prototyping with a PIC, a development board normally is used. PIC development boards provide an easy way to prototype a PIC application by allowing a range of input power options and easy access to the input and output pins for the chip. It is not necessary to use this, but it makes creating a prototype easier.

We used the OOPIC development board/system by Savage Innovations. It is inexpensive and provides a simple object interface for many input and output devices, including buttons, encoders and RS-232 serial communication. Unfortunately, there is no Linux development environment for OOPIC, although a SourceForge project is underway.

The hardware is rounded out with a Gateway Solo 5150 laptop that has a broken LCD. Similar laptops go for between $50 and $100 on eBay.

Figure 2. The original chassis is used to mount the controls, PIC development board, LCD and power supply.



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Woah, love the idea of this.

Luc's picture

Woah, love the idea of this. There are quite a few stations I like to listen to that are forgien so obviously don't boradcast within a few 1000 miles of where I live. This would be a great way to listen to them around the house. So when does production start?

Great Prototype

Dave's picture

A very interesting article. Your prototype now allows you to show people the concept,something they can get their hands on.

Never OO embedded devices

James's picture


On the surface, your homespun project looks impressive. However,
as an embedded expert, your 'project' demonstrates everthing
wrong with many if not most product development efforts.
1. OO programming for embedded devices, is doom to failure
for a variety of reasons: security, maintainance, portabilty
but mostly costs.
2. You project could be implemented on a $5 x86 embedded CPU, avoiding
the pc mobo and the PIC all together. You have to have hardware and
firmware engineers minimize the hardware design before you start
3. Features that are missing are killers. Traditional AM/FM radio
support must be added, using a chip that costs a few dollars so as
to attract the tradition radio market. Upon using the AM/FM radio
features, as a comfortable commodity, you can then attact them
to Internet radio. NTP and the ability to filter out commercials
over traditional AM/FM broadcast would make your product much more
financially viable.

I could go on and on, but I hope you start to see clearly. The
problem with product development, is it starts with expertise
in hardware and firmware. Embedded linux is fantastic, but, you
never, never, never use a distro espcially pocket PR or Fedora,
as all of that excess baggage wastes critical resoures and leads
to unstable products that are expensive to maintain.

Last, if you are going to build embedded products, LEARN ASSEMBLER
mixed in with ansi C. Leave OO on the destops, where it belongs..

James Horton, BSEE, MSCS PE.

Some do and some talk

K2TQN's picture

I think this is a great project just as it is. It's a great new idea and it has been implemented. I put them in the same league with Bell, Edison, the Wright Brothers, Marconi, DeForest, Mauchly and Eckert, Woz and Jobs, and all the others who forged ahead and were first!

Of course everything can be improved, but they did it, and did it first.


John Dilks, K2TQN
Personal Computing Pioneer (1976)

I agree completely if this were a final product

Dan Rasmussen's picture

Hi James,

You are universally correct in your assesment of the device as a final product and I am glad your brought it up. One of the points of the article that may not have been made well is, as a prototype, our primary goal was to minimize effort/cost get it done as quickly as possible.

Had we done all of the things you mentioned, it would have taken much much longer than the month or two that it did take (and much of that time was spent soldering). Prototyping is extremely important in the development of any software or system and we needed to have a prototype to have any hope of getting funded and this was it.

Had we received funding for the idea, the device was to include some of your suggestions and many other features not mentioned. Our fist technical task after receiving funding would have been to get it on an embedded system (we were considering Gumstix - - as the next step but not necessarly the final platform - we still had lots of work to do).

Prototyping is about getting something together that looks complete but doing it as quickly/cheaply/easily as possible. Optimization comes when you have the time/money/resources to do that. Some of that message may have been lost as the article went through its many revisions (We had to get rid of lots of words).

Thanks for the comments.

Dan Rasmussen

still pursuing the Internet Radio project?

Tracy R's picture

Hello .. I came across your article regarding your Internet Radio device while I was doing a search for exactly that type of product. If you (..or any one else out there) ever needs cheap(free!), quality labor designing this product, feel free to contact me any time ( I have 20+ years in New Product Development for many different products. Let's do it!
Tracy R.

Assembler not always needed

Barton's picture

While I agree with most of your comments I don't think that assembly language is needed very often. I have done many embedded applications and very seldom need to fall back on assembly language. Even when doing DSP projects the C compilers are very capable of creating very optimized code. If one does need a little bit of assembly it can usually be added in line with a C extension like asm {} or the like. With DSP's one does usually need a little bit of start up assembly but it is only a page of code. Assembly language is hard to code, hard to maintain, and hardest still to port to other processors. When ever possible I try to make do with ANSI C. I agree that OO and C++ are usually overkill for an embedded application unless it has an OS to fall back on. An embedded system using one of the embedded Linux products could support OO if the project was real big. Most of the time however the embedded projects I work on don't need any OS and must fit into small spaces. PIC's and DSP projects for hardware control usually don't need the extra overhead of an OS.

Of course that's my opinion, I could be wrong.

next step ?

ben ciceron's picture

wow ! great.
let's find a linux friendly palmtop or mp3 player and we might have winner...

When and where, I'd buy!

Ed O'Neil's picture

You've got a GREAT idea. Broadcast radio reception where I live isn't that great so a device like yours is very atractive. In the mean time, I will continue to use an inexpensive ($15-20) FM transmitter to re-broadcast from my PC to all of the radios in my home. You could intigrate something similar in yours so that the listener could roam the house and hear the same station. If you need a beta tester...

Retro Radio

Frank Daley's picture

There IS a market for something like this. Just look at the huge success that Chrysler had with their retro PT Cruiser:

There are even some interesting similarities between the two. Surely there is at least one VC company with some vision!!

Good luck, it would be a winner if it went to production.

Uhhhh. The PT Cruiser is a h

Anonymous's picture

Uhhhh. The PT Cruiser is a hacked Neon. Not in the least bit retro.

Internet radio and Music servers

Anonymous's picture

very interesting project, I was actually looking at some music servers that offer Internet radio, such as the musica from and the sonos from , if end not purchasing a music server, and this product becomes a reality, I may end up getting one

One thing I didn't understand

Dave's picture

One thing I didn't understand was how the consumer uses it. It looks like they select a genre from the dial, then how does the radio know what stations to list? Does the user have to enter them somehow? Will it work wireless (using a hot spot)? Over-all it seems very cool!



Dan Rasmussen's picture

Hi Dave,

Thanks for the positive comments. Possibly not explained well was that there is a genre dial and a turner dial. Twiddle the genre dial and the LCD will update to the new genre. Once you get the the desired genre, twiddle the station dial and the LCD updates with new selections from the genre.


XML station identification

Glider's picture

The XML configure script allows for the storing of radio stations.

I don't see where the authors allow for this lsit to be updated except for someone with command line access editting the configuration file. However I could see where it could be set up to populate radio stations from the web using an RSS feed or something similar.

Great article!


XML station builder script

Dan Rasmussen's picture

Hello -G-,

Yes, you are correct, there is no mention of how this file gets generated. If you take a look at the resources page it will lead you to a page that gives a little bit of an explanation but it goes like this: yes there is a script that will generate the xml config file (well, sort of, it still needs a bit of hand editing). It does this by querying a well known station list keeper (that actually limits your daily queries - based on IP). At the same site ( You will also find a stale xml station file along with all of the associated source. The station gen scrip is not yet posted but everything else is. I need to clean it up a bit first.

Thanks for the positive comments.



ken Scharf's picture

Well it's now December 27 and you STILL havn't put the station list generater scrpit up on your web site.

Also I have an optical encoder switch that has a push button switch built in. I can see rewriting the interface so the single dial could switch between 'bands' and 'stations' with the push button selecting which menu and making the selection. (quick push changes menus, long push makes selection.)

Well written and inspiring. A

jh's picture

Well written and inspiring. Almost makes me regret having become a software-only geek :-)

Great Job!!

Richard Kut's picture

Wow! Great job! Any plans on selling some of these to guys like me?

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