About the BS2SX

Parallax recently introduced the Basic Stamp IISX. This is a souped-up Basic Stamp II. We've been working with the 2SX for some time, and now that it is released, I can tell you a little about it. Here's the high points:

bullet10,000 instructions per second (50Mhz clock)
bulletThe chip can store 8 2K programs (16K total) -- only runs one program at a time
bullet63 bytes of scratch pad RAM - this is extra RAM that you access using GET and PUT (see below)

There are a few things that you should know, however:

bulletThe faster speed changes many commands. For example, maximum PULSIN is 52.4ms. The upside to this is that the resolution is 800uS.
bulletThe logic 1 threshold is 2.5 volts (instead of 1.6V) which may affect some RCTIME circuits.
bulletThe 5V regulator supplies 150mA. The Stamp takes 60mA plus whatever current is flowing from the I/O pins. That means your circuit can't draw as much current as you could with the Stamp II.

There are three new commands:

  1. PUT - Write to scratch pad RAM
  2. GET - Reads from scratch pad RAM
  3. RUN - Executes another program

The scratch pad RAM is essential for passing parameters between programs. Remember, only one program runs at a time. Initially, program 0 runs. You can then switch at will between any program from 0 to 7. Each RUN starts your program at the top, but your registers (including I/O) remain the same. You can determine the number of the currently running program by reading scratch pad location 63.

Note: Earlier on this page I mentioned that the RUN command reset your variables and your I/O pins. This was true on prerelease engineering samples, but not true on the final product. Sorry for any confusion this may have caused.

You can find the entire data sheet for this new part at ftp://ftp.parallaxinc.com/pub/acrobat/stamp2sx_manual_v1.0.pdf.

Oh, by the way, our ASP-II works great with this part. Check it out

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