Radio's Next Generation: Radii
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.
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.
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.