Analog to Digital Converter

sumguy16

I've been reading the documentation on the SX - chips and I saw that a A/D converter is built in. I must be blind because I can't find any documentation or posts regarding this subject, can someone help?

Thanks,
Adam Przybilla

Jon Williams

It does not have an A2D built in, but there are a a few ways you can make one. The latest SX/B help file shows an 8-bit version that uses an RC circuit and the onboard comparator.

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Jon Williams
Applications Engineer, Parallax

Beau Schwabe

Adam,

What you may be refering to is the description of each of the SX chips....

The Ubicom SX is a RISC architecture, high-speed microcontroller with flash program memory, in-system programming and debugging capability. Operating at frequencies up to 75 MHz with an optimized single-cycle instruction set, developers can implement real-time functions as software modules. Common examples include communication interfaces (I2C, SPI, UARTs), frequency generation and measurement, PWM, and sigma-delta A/D.

...The last sentence starts out by saying "Common examples..." one of those being a sigma-delta A/D

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Beau Schwabe

IC Layout Engineer
Parallax, Inc.

sumguy16

That makes sense, sorry for the confusion.
Jon, I saw you posted an 8-bit solution with an RC circuit, is it even possible to a 12-bit A2D without an extra IC, space is a bit of a concern for my project.

Thanks,
Adam

Jon Williams

If you checkout www.sxlist.com (while it's still up) there is a note posted there by a user that he was able to get 12-bit resolution form a Sigma-Delta A2D (virtual peripheral).

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Jon Williams
Applications Engineer, Parallax