Adafruit TCA9548A I2C Multiplexer

You have just found the perfect I2C sensor and want to connect two, three, or more of them to your Arduino, but then you realize: "Uh oh, the chip has a fixed I2C address, and from what I know about I2C, you can't 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!

Finally, there is a way to connect up to 8 I2C devices with the same address to a microcontroller. This multiplexer acts as a gatekeeper, forwarding commands to the selected set of I2C pins.

Using it is quite simple: The multiplexer itself has the I2C address 0x70 (but can be set from 0x70 to 0x77). You can simply send a single byte with the desired multiplexed output number to the port, and all future I2C packets will be sent to that port. Theoretically, you could use 8 of these multiplexers at addresses 0x70 to 0x77 to control 64 devices with the same I2C address.

As with all Adafruit breakouts, we have brought this nice chip to a breakout board for you, so you can use it on a breadboard with capacitors and pull-ups as well as pull-downs, making usage a breeze. Some headers are required, and once soldered, you can plug it into a breadboard. The chip itself is compatible with both 3V and 5V, so you can use it with any logic level.

Technical details:

• Weight: 1.8 g
• Selectable I2C address: 0x70-0x77.