Built a Parallax Propeller minimal barebones board

Posted at 2015-07-19.

I finally decided to put together something for the Parallax Propeller chips. I have a pair of Propeller 1 P8X32A-D40 chips lying around, but never set them up. I also have a laptop I need to test drive and a moment to spare, so to say.

Yes, I'm exploring the evil side of the world for a change. Mostly hoping to expand my abilities through random software.

Install

Propeller bare bones board

I installed the Propeller tool v1.3.2 on Windows 8.1 (64b). It's surprisingly hard to find versions of the tools, but browsing around, I found SimpleIDE (C) and Propeller Tool (SPIN).

For a board, I roughly followed the schematic found linked called Bare bones Propeller 1.4. I used a piece of blue protoboard, a few discretes and legs as jumpers.

There are a few things to comment on the design. Quck and dirty, but (mostly) functional.

Testing

Propeller outputs garbage

I ran the IDE and loaded the program and looked around the menu to figure out how to run and upload. It is a very simple program indeed.

I fumbled with the wiring, but eventually got together a setup with a CP2104 USB adapter and the blue board and powered the design from the internal regulator on the CP2104.

No cap smoke or heat, F7 detects chip, F10 uploads, and F12 shows garbage at any rate but least garbage with 1200 bps.

Propeller outputs demo text

Attaching a better 3.3 V supply shows the same. Accidentally, while disconnecting, I noticed that the output turns correct if all power is disconnected! Turns out the 221 R (yes, funky size) pull up will serve enough power from DTR to run the chip. Why it runs fine probably has something to do with BOR watch or somethig and I should look into it. It seems the voltage changes might be affecting internal oscillator frequency.

Plans

The party piece here might be the video generators, but surely there's lots of ways to use the chip. Exploring the "object exchange" would make a nice first step.

Naturally exploring the C option and toolchains fit for my Debian desktop may also enter in in case I'm actually making something.

XTL :: blog