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SV: [basicstamps] I2C, see if I actually understand it. — Parallax Forums

SV: [basicstamps] I2C, see if I actually understand it.

ArchiverArchiver Posts: 46,084
edited 2002-10-07 20:45 in General Discussion
Greetings!

> You would, in fact, need 10 pins for eight DS1620s.
> You would need two for clock and data, then one for
> each chip select (called Reset on the DS1620).

Hogwash!

You need the clock and data pins, and then you throw in a demultiplexer
chip, like the 74HC138 which gives you 8 chip selects for the count of 3
pins on the Stamp...
(You can of course cascade these chips, hooking the CS pins of 8 HC138's to
the outputs of another HC138, getting 64 Chip selects for a total of 6CS and
2Data/clock pins on the Stamp)

Or, if you can find chips with the same functionality in DalSemi's 1-Wire
chip series, you only need 1(!) pin no matter how many chips you're using...
(They're addressed with a 64bit factory lasered serial number and uses a
strict master/slave protocol)

I've had 20 chips wired up to my BS2p24 at one time...
(Just to prove a point, not to actually use it for anything :-)

:-)
Trygve
http://home.ci.net/trygveh/english/
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