I'm working on a electronic prototype. I have got one I2C communication master and I have six slaves to talk to. But here is the problem: the components are not built to have many addresses: only two are available.

So I have got two possible solutions:

  • The first is to program the processor to give me three I2C masters. This isn't very convenient.

  • The second one is to use a demux component which uses a mechanical connection between the slave and the master like a relay connection (classic demux are buffering signals).

Do you know of such a chip? Or is there another option?

  • \$\begingroup\$ besides specialized solutions as ThreePhaseEel suggested (which are the best options), I can say that I tested and had a simple 4052 analog MUX work while switching between 3 pairs of devices with conflicting addresses. So if you want to test the concept you can start with jellybean ICs \$\endgroup\$ – Wesley Lee Jul 4 '16 at 16:55

While in theory a transmission-gate (analog) mux could be used for this, there are dedicated I2C multiplexer ICs out there that may work better for your application -- see the PCA9545A for an example of a part that's suitable for your application.

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    \$\begingroup\$ Hey. Thanks for your answers, I didn't know it could exist a specific component which demux I2C. Plus It seems to be really easy to wire. Thanks again. \$\endgroup\$ – Joe Lara Jul 4 '16 at 15:20
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    \$\begingroup\$ @JoeLara -- don't forget to accept + upvote the answer since it helped you. \$\endgroup\$ – ThreePhaseEel Jul 4 '16 at 15:36
  • \$\begingroup\$ Sorry but I already did it but I think my account is to recent for my answer to be validated :S \$\endgroup\$ – Joe Lara Jul 5 '16 at 15:54
  • \$\begingroup\$ @JoeLara -- no worries. \$\endgroup\$ – ThreePhaseEel Jul 5 '16 at 22:34

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