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Full machine-readable index: https://core-electronics.com.au/llms.txt # Adafruit PCA9548 8-Channel STEMMA QT / Qwiic I2C Multiplexer - TCA9548A Compatible **Type:** Product page · **SKU:** ADA5626 · **Brand:** [Adafruit](https://core-electronics.com.au/brands/adafruit-australia) **Page:** https://core-electronics.com.au/adafruit-pca9548-8-channel-stemma-qt-qwiic-i2c-multiplexer-tca9548a-compatible.html ([markdown](https://core-electronics.com.au/adafruit-pca9548-8-channel-stemma-qt-qwiic-i2c-multiplexer-tca9548a-compatible.html.md)) You just found the perfect I2C sensor, available in a handy chainable Qwiic, or STEMMA QT package, and you want to wire up two or three or more of them to... ## Pricing - **Price:** $12.40 (inc GST) — $11.27 AUD, exc GST - **Quantity discounts:** 10+ $10.94 (exc GST) · 50+ $10.71 (exc GST) ## Availability & dispatch - In stock, ships same business day if ordered before 2PM (Australia/Sydney). - We can dispatch 11 today, and up to 50 more in 8–12 days. ## How to buy - **Build a cart:** compose `https://core-electronics.com.au/cart/link?items=ADA5626:1` (comma-separated SKU:qty pairs) and share the link. 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Share the cart link; checkout takes it from there. - **Search the catalogue:** `https://core-electronics.com.au/search/{query}.md` (URL-encode the query; pages 2-3 at `search/{query}/{page}.md`; `search.md?q=` also works) - **Payment methods, purchase orders, policies and contact details:** https://core-electronics.com.au/llms.txt ## Description You just found the perfect I2C sensor, available in a handy chainable [**Qwiic, or STEMMA QT**](https://learn.adafruit.com/introducing-adafruit-stemma-qt) package, and you want to wire up two or three or more of them to your microcontroller 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 **Adafruit PCA9548 8 Channel STEMMA QT / Qwiic I2C Multiplexer**! 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 I2C port with your command. **In case you're wondering why this uses the PCA9548A not the [TCA9548A](https://core-electronics.com.au/tca9548a-i2c-multiplexer.html)**, the PCA9548 is the 'fraternal twin sister' of the TCA9548 but is easier to get during the great chip shortage of 2022. It works exactly the same, just can't go down to 1.8V power which is OK because QT boards are 3V or 5V only anyways. [You can still use any example code or library for the TCA9548](https://learn.adafruit.com/adafruit-tca9548a-1-to-8-i2c-multiplexer-breakout/overview) Using it is fairly straight-forward: the multiplexer itself is on I2C address 0x70 (but can be adjusted from 0x70 to 0x77 using jumpers on the back) 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. The **Adafruit STEMMA QT / Qwiic PCA9548A Mux Breakout - 8 Channel** has eight JST SH 1mm connectors in two rows of four, all with the power, ground, and SDA/SCL pins connected. There's one port at the end that connects to your I2C controller (there are also breadboard breakout pins if you need them). Use this breakout to add as many I2C devices to the bus as you need. Complete with mounting holes so the board can be added to any system. A small power LED lets you know that the hub board has connectivity. There's even an onboard 3.3V 500mA regulator, so if you're using this with a 5V microcontroler like an Arduino 328-compatible, you can level shift all the QT ports to have 3V power and logic level. Of course, because [STEMMA QT is Qwiic compatible](https://learn.adafruit.com/introducing-adafruit-stemma-qt), it will [work with any and all STEMMA QT or Qwiic boards and parts Adafruit have in the Adafruit shop](https://core-electronics.com.au/search?q=stemma%20qt). Comes with only the assembled PCB, no cables or sensors included. ## Technical Details Product Dimensions: 40.6mm x 20.2mm x 4.8mm / 1.6" x 0.8" x 0.2" Product Weight: 5.1g / 0.2oz ## Images - [Product image 1](https://core-electronics.com.au/media/catalog/product/A/D/ADA5626-3.jpg)