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Topic: i2c beginner question (Read 705 times) 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 !

Groove

Quote
What kind of electronic component should I buy


One with a different address to the first device.
Per Arduino ad Astra

strus_fr

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

Groove

No, I2C is a bus, the devices are in parallel.
All the SCLKs are connected together, and all the SDAs are connected together.
Per Arduino ad Astra

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?

Groove

That device is a way of adding extra digital I/O pins to a design, it isn't any kind of bus repeater.
Per Arduino ad Astra

strus_fr

ok, I think it is clearer now. Thanks

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