Quick question about TCA9548A addressing

hi guys

I have a quick question about setting the address for the TCA9548A. I'm new to Arduino so I think it's probably easy to answer, but I couldn't find anything specific enough on the web.

I have two TCA9548A multiplexers and they both come with 0x70 (or 1110000) as their default address, and I've am trying to change one of them using the A0 - A2 pins.

I got it to work, but it doesn't seem to save the address... as soon as I remove the signal it switches back to the old address. So I'm wondering if there's a way to make it stick or if I have to constantly send a HIGH signal to it in order to change the address?


Hi, @gabechan
Welcome to the forum.

Please read the post at the start of any forum , entitled "How to use this Forum".

Can you please post a copy of your circuit, in CAD or a picture of a hand drawn circuit in jpg, png?

Are you using the IC on its own or a module PCB with the 9548?

Are you permanemtly connecting A0 -A2 pins to gnd or Vcc?

Thanks.. Tom... :grinning: :+1: :coffee: :australia:

@gabechan You need to tie the address pins to either supply or ground permanently to configure the address. The levels are not remembered by the chip.

1 Like

yup, that's it. thanks!

thanks for the reply! sorry, but just because I'm not sure what to make of your comment ... which Forum rule did I not observe?


You haven't broken any mate.
We just point new members there to let them know what different things you can do with the forum parameters/instructions.

Tom... :grinning: :+1: :coffee: :australia:

Ah, ok, thought I forgot smth for a moment. :stuck_out_tongue:

Thanks for the help!

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