I2C & 3-wire Serial ????
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I never heard of these two protocols and no clue as to how would one
uses the BS2 to communicate with them.
Please help with explanation or direction as to where to find
answers..
Al Najjar
uses the BS2 to communicate with them.
Please help with explanation or direction as to where to find
answers..
Al Najjar
Comments
See http://www.high-techgarage.com/
SPI/Microwire can be done with the shiftin/out commands.
From National, Motorola and others.
>
> I never heard of these two protocols and no clue as to how would one
> uses the BS2 to communicate with them.
>
> Please help with explanation or direction as to where to find
> answers..
>
> Al Najjar
>
commands to deal with I2C and Dallas Semi 1-Wire
devices. I2C uses 2 pins and 1-Wire uses 1 pin to
communicate with an external device, usually an IC.
My understanding is that both allow something like 100
devices to comunicate with the same 1 or 2 wires.
Communication with the devices takes place using
addresses, which are globally unique. If you have 1
chip from the FooBar family / product line, you can
address it as FooBar, just like addressing someone by
their family name. This is good if you're making many
of the same product. If you have a bunch of FooBar
chips, though, it's like a family reunion in that you
need to address the device by its full id, globally
unique, with tillions upon trillions of possibilities.
That would limit the usefulness for production, since
each FooBar chip you use needs to be uniquely
addressed, and any replacements require code changes.
Apparently there are some routing chips available to
address this limitation, but again, this is all my
understanding and subject to review by wiser people.
SPI/Microwire is the mainstay of the Stamp and other
processors that need to connect to shift register-type
devices. You must assign a CS pin, CLK pin, and DATA
pin, each subject to several different names.
Sometimes a separate SDI and SDO (serial data in and
serial data out) pin is used, but generally if the
device you are talking to has both a data in and a
data out pin (some do not), you can tie both to one
Stamp pin and connect them with a resistor (see
diagram under "SERIN" in the Stamp manual). Once you
have one 3-wire serial device connected, each
additional device requires only a separate DATA pin;
they can all share the same CS and CLK.
Bob Pence
--- Mike DeMetz <miked@t...> wrote:
> I2C is a 2 wire bidirectional interface. From
> Phillips
> See http://www.high-techgarage.com/
>
> SPI/Microwire can be done with the shiftin/out
> commands.
> From National, Motorola and others.
> >
> > I never heard of these two protocols and no clue
> as to how would one
> > uses the BS2 to communicate with them.
> >
> > Please help with explanation or direction as to
> where to find
> > answers..
> >
> > Al Najjar
> >
>
>
>
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=====
Regards,
Bob Pence
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