Hardware Reference
In-Depth Information
an embedded programming language called Wiring which has built-in all the bells
and whistles required to control real-time devices. What makes the Arduino plat-
form fun to use is its large and active development community. There are thou-
sands of published projects using the Arduino, ranging from an electronic pollutant
sniffer, to a biking jacket with turn signals, a moisture detector that sends email
when a plant needs to be watered, and an unmanned autonomous airplane. To learn
more about the Arduino and get your hands dirty on your own Arduino projects, go
A step up are the mobile platforms and video game machines. They are nor-
mal computers, often with special graphics and sound capability but with limited
software and little extensibility. They started out as low-end CPUs for simple
phones and action games like ping pong on TV sets. Over the years they have
evolved into far more powerful systems, rivaling or even outperforming personal
computers in certain dimensions.
To get an idea of what is inside these systems, consider the specifications of
three popular products. First, the Sony PlayStation 3. It contains a 3.2-GHz multi-
core proprietary CPU (called the Cell microprocessor), which is based on the IBM
PowerPC RISC CPU, and seven 128-bit Synergistic Processing Elements (SPEs).
The PlayStation 3 also contains 512 MB of RAM, a 550-MHz custom Nvidia
graphics chip, and a Blu-ray player. Second, the Microsoft Xbox 360. It contains
a 3.2-GHz IBM triple-core PowerPC CPU with 512 MB of RAM, a 500-MHz cus-
tom ATI graphics chip, a DVD player, and a hard disk. Third, the Samsung Galaxy
Tablet (on which this topic was proofread). It contains two 1-GHz ARM cores
plus a graphics processing unit (integrated into the Nvidia Tegra 2 sys-
tem-on-a-chip), 1 GB of RAM, dual cameras, a 3-axis gyroscope, and flash memo-
ry storage.
While these machines are not quite as powerful as high-end personal com-
puters produced in the same time period, they are not that far behind, and in some
ways they are ahead (e.g., the 128-bit SPE in the PlayStation 3 is wider than the
CPU in any PC). The main difference between these machines and a PC is not so
much the CPU as it is their being closed systems. Users may not expand them
with plug-in cards, although USB or FireWire interfaces are sometimes provided.
Also, and perhaps most important, these platforms are carefully optimized for a
few application domains: highly interactive applications with 3D graphics and mul-
timedia output. Everything else is secondary. These hardware and software restric-
tions, lack of extensibility, small memories, absence of a high-resolution monitor,
and small (or sometime absent) hard disk make it possible to build and sell these
machines more cheaply than personal computers. Despite these restrictions, mil-
lions of these devices have been sold and their numbers are growing all the time.
