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Parallax Propeller

Details: Category: Articles; Created: Sunday, 03 May 2009 19:48; Last Updated: Saturday, 05 January 2019 05:58; Written by Rick Swenton; Hits: 6966

I got bitten by the bug again. Over 16 years ago I developed a microprocessor system to control my Ham Radio repeater. I have not really done much hardware or software development since then. Things sure have changed. I obtained a Parallax Propeller development board to start learning more about this fascinating chip. [I am not affiliated with Parallax. Any views or opinions presented here are my own, including my excitement.]

[From the Parallax Web Site:] The Propeller chip makes it easy to rapidly develop embedded applications. Its eight processors (cogs) can operate simultaneously, either independently or cooperatively, sharing common resources through a central hub. The developer has full control over how and when each cog is employed; there is no compiler-driven or operating system-driven splitting of tasks among multiple cogs. A shared system clock keeps each cog on the same time reference, allowing for true deterministic timing and synchronization. Two programming languages are available: the easy-to-learn high-level Spin, and Propeller Assembly which can execute at up to 160 MIPS (20 MIPS per cog).

The development board is on the right. Just plug in a 9V power supply and a USB mini cable. Download the free Propeller Tool Software and you will be sending demo programs to the onboard EEPROM over USB in no time. The Propeller Tool Software is a full-featured Integrated Development Environment (IDE) that consists of an editor, complier/assembler and USB and serial downloader. Parallax also provides a terminal program so you can interact with the Propeller in real time through a console window.

The Propeller Object Exchange contains many source code objects for the Propeller microcontroller. They are created and submitted by Propeller customers as well as Parallax engineers for use by everyone in the community.

The object-based high-level Spin language is easy to learn, with special commands that allow developers to quickly exploit the Propeller chip’s unique and powerful features. Propeller Assembly instructions provide conditional execution and optional flag and result writing for each individual instruction. This makes critical, multi-decision blocks of code more consistently timed; event handlers are less prone to jitter and developers spend less time padding, or squeezing, cycles.

This is a view of the Parallax 32812 Propeller Proto Board USB. Notice the 15-Pin VGA connector in the upper right. Below it (not seen) is a PS2 Keyboard connector and a PS2 mouse connector. After firing up the Propeller Tool Software I had graphics and text being displayed from some of the demo programs in a matter of minutes. I wanted to try my hand at lighting some LEDs. I soldered a 16 pin DIP socket in line with 8 I/O pins so I could bring a ribbon cable out to the proto board below.

Here on the right side of the board I installed a ten segment DIP led display with eight dropping resistors. I had those LEDs blinking on command in no time. I plan to write more about this as I have some time to become familiar with this exciting device. My hope is to develop some useful home automation applications that will include remote monitoring over the Internet.