SparkFun Qwiic Mux Breakout - 8 Channel (TCA9548A)

The SparkFun Qwiic Mux Breakout is a powerful and elegant solution for one of the most common challenges in I²C communication: address conflicts. Built around the TCA9548A I²C multiplexer, this breakout allows a single microcontroller to communicate with up to eight I²C devices that share the same address by isolating them on separate channels.

Functioning like a digital 8-position switch for the I²C bus, the multiplexer routes communication to one selected channel at a time. By sending a simple I²C command, users can choose which channel (0–7) is active, ensuring reliable and conflict-free communication with each connected device.

Designed for seamless integration, the board is fully compatible with the SparkFun Qwiic Connect System and features 10 Qwiic connectors—two for the main bus (pass-through for daisy chaining) and eight dedicated to the multiplexed channels. This enables fast, solder-free assembly of complex sensor networks.

For large-scale projects, the multiplexer itself supports eight selectable I²C addresses via onboard solder jumpers. This allows up to eight Qwiic Mux boards on a single I²C bus, expanding system capacity to an impressive 64 identical-address devices.

The board supports a wide voltage range from 1.65V to 5.5V, making it suitable for both 3.3V and 5V systems. Standard 0.1" header pins are also broken out for users who prefer breadboard or wired connections.

Specifications

Multiplexer IC: TCA9548A

Operating Voltage: 1.65V – 5.5V

Operating Temperature: -40°C to +85°C

I²C Address:

Default: 0x70

Configurable up to: 0x77

Channels: 8 independent I²C channels

Qwiic Connectors:

10× total

2× pass-through (daisy chain)

8× multiplexed channels

Address Selection:

3 onboard solder jumpers (ADR)

Pin Spacing: 0.1" standard headers

Documentation

• Schematic (v1.1)
• Eagle Files (v1.1)
• Hookup Guide
• Board Dimensions (v1.1)
• TCA9548A Datasheet (TCA9548A)
• Libraries:
  • Arduino
  • Python / MicroPython / CircuitPython
• ReadtheDocs Documentation
• Qwiic Resource Page
• GitHub Hardware Repository (v1.1)

Applications

Connecting multiple identical I²C sensors

Large sensor arrays and data acquisition systems

Robotics and automation projects

IoT and smart environment monitoring

Educational and prototyping platforms

Qwiic-based modular systems