A WHOLE SYSTEM OF POS-
SIBILITIES — EVEN AN ENTIRE
COMPUTER — AWAITS YOU
IN THIS SIMPLE CHIP.
By Ken Gracey
The Propeller’s architect, my brother Chip, has
roots in vintage computing, which helps explain
the “whole system” features designed into this
single chip. The chip performs basic microcontroller
functions very easily, yet it can also be an entire
small computer once you add the keyboard, mouse,
The Propeller can execute 160 million instructions per second across its 8 processors while
consuming only 80mA. Each processor can be
dedicated toward a single task, and variables are
globally available to other processors in Propeller.
There are no interrupts in this chip — the concept
is that you’d dedicate a cog to managing repetitive,
externally driven tasks. A configurable timer makes
scheduled events straightforward.
This hardware is made useful through an object-oriented, high-level programming language called
Spin. The Spin interpreter is actually built into the
Propeller’s ROM hardware. Spin looks a bit like
BASIC and C++, but customized for the Propeller’s
Propeller programmers can go to the Parallax
Propeller Object Exchange and download hundreds
of code modules for serial communication, VGA/TV
display, mice, math, keyboards, motor control, and
sensors, and link them together in a “top” Spin program. Beginners can use objects off-the-shelf, and
engineers can customize. You can also program the
Propeller in good ol’ assembly language.
AND WITH THIS POWER?
Applications possible with a single Propeller include:
» CNC controller. Simultaneous generation of
stepper motor signals, receiving serial or parallel
data from a PC, user interface with a mouse and
VGA/TV display, and interface for E-stop buttons
and limit switches.
ABOVE: Gaming guru Andre LaMothe’s Hydra Game
Console ( hydraconsole.com) is the first commercial
application based on the Propeller chip.
BELOW: The Propeller Proto Board can be used for
» Oscilloscope and signal generator.
Electronic data interpretation, adaptable triggering.
» Sensor processing and robotic navigation.
Concurrent processing of data from GPS, ultrasonic, infrared, compass, and encoder sensors while
generating PWM for motor control.
» Video games. Simultaneous interface to joystick,
keyboard, and mouse, with Propeller-to-Propeller
networking, all while displaying the game on TV.
But it’s the simple projects where most of us are
already putting Propeller to use. Parallax’s history
in educational documentation and personalized
support should give you some comfort in your first
Go to parallax.com/propeller to get started
programming the Propeller. There, you’ll find kits,
educational labs, and free downloads of all object
code, plus a manual and the Propeller software tool.
Ken Gracey is vice president of Parallax, Inc.