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Topic: i2c beginner question (Read 1 time) previous topic - next topic

strus_fr

Feb 11, 2010, 04:14 pm Last Edit: Feb 11, 2010, 04:15 pm by strus_fr Reason: 1
Hi

I successfully plug an i2c RTC clock with my Arduino board.
Now, I have other i2c components that I would like to plug also (EEPROM for example, and probably more to come).

What kind of electronic component should I buy (not a serial to parallel Shift-register I guess... )?

Does someone has an example of such a wiring? ... may be also a piece of code  ;)

Thanks !

GrooveFlotilla

Quote
What kind of electronic component should I buy


One with a different address to the first device.
Some people are like Slinkies.

Not really good for anything, but they bring a smile to your face when pushed down the stairs.

strus_fr

well, does that mean that I only have to put them in series?  :-/

GrooveFlotilla

No, I2C is a bus, the devices are in parallel.
All the SCLKs are connected together, and all the SDAs are connected together.
Some people are like Slinkies.

Not really good for anything, but they bring a smile to your face when pushed down the stairs.

strus_fr

ok, so what is the purpose of the i2c i/o expander I saw here:
http://www.neufeld.newton.ks.us/electronics/?p=241&cpage=1

is it needed only if you have the same address?

GrooveFlotilla

That device is a way of adding extra digital I/O pins to a design, it isn't any kind of bus repeater.
Some people are like Slinkies.

Not really good for anything, but they bring a smile to your face when pushed down the stairs.

strus_fr

ok, I think it is clearer now. Thanks

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