TCA9548A I2C Multiplexer

by Adafruit

Finally, a way to get up to 8 same-address I2C devices hooked up to one microcontroller - this multiplexer acts as a gatekeeper, shuttling the commands to the selected set of I2C pins with your command.

You just found the perfect I2C sensor, and you want to wire up two or three or more of them to your Arduino when you realize "Uh oh, this chip has a fixed I2C address, and from what I know about I2C, you cannot have two devices with the same address on the same SDA/SCL pins!" Are you out of luck? You would be, if you didn't have this ultra-cool TCA9548A 1-to-8 I2C multiplexer!

Using it is fairly straight-forward: the multiplexer itself is on I2C address 0x70 (but can be adjusted from 0x70 to 0x77) and you simply write a single byte with the desired multiplexed output number to that port, and bam - any future I2C packets will get sent to that port. In theory, you could have 8 of these multiplexers on each of 0x70-0x77 addresses in order to control 64 of the same-I2C-addressed-part.

Like all Adafruit breakouts, they put this nice chip on a breakout for you so you can use it on a breadboard with capacitors, and pullups and pulldowns to make usage a snap. Some header is required and once soldered in you can plug it into a solderless-breadboard. The chip itself is 3V and 5V compliant so you can use it with any logic level.

Adafruit even wrote up a nice tutorial with wiring diagrams, schematics and examples to get you running in 10 minutes!

Note: You may get an off-white or black JST connector.

Technical Details

Weight: 1.8g

Product Dimensions: 30.6mm x 17.6mm x 2.7mm / 1.2" x 0.7" x 0.1"

5 customer reviews

3 years ago
High-quality board and assembly. Easy to use and excellent examples. In a circuit, the multiplexer works well, solving a problem I had with fixed I2C addresses on multiple displays.
by Anonymous about TCA9548A I2C Multiplexer via REVIEWS.io
4 years ago
Great little breakout for when you need to add multiple I2C devices to a project and only have one interface on your board. Used this to run multiple OLED devices on the circuitpython playground express. Code examples were clear and easy to follow/adapt to my own project
by Hugh about TCA9548A I2C Multiplexer via REVIEWS.io
5 years ago
If you have devices with conflicting I2C addresses, this thing will solve your pain. You can program it as you wish. This one is great where form factor matters
by Andris about TCA9548A I2C Multiplexer via REVIEWS.io
5 years ago
There are a few competitors to this board, but I like the size, flexibility and expandability of this one. Essential if you're using two I2C boards with the same fixed address. It's a shame there isn't something like this to enable two of the PMW3901 Optical Flow Sensors to cohabitate, but alas it connects via SPI rather than I2C.
by Murray about TCA9548A I2C Multiplexer via REVIEWS.io

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