CJMCU TCA9548A I2C 8 Channel Multiple Extensions Development Board

CJMCU TCA9548A I2C 8 Channel Multiple Extensions Development Board provides an elegant solution for resolving I2C address conflicts when connecting multiple identical sensors or displays to a single microcontroller. This sophisticated multiplexer chip acts as a gateway, allowing you to switch between eight different I2C buses using simple software commands. Consequently, you can connect up to eight devices with the exact same I2C address to one master controller without any signal interference. Furthermore, the board supports voltage level translation between 1.8 V, 2.5 V, 3.3 V, and 5 V buses, which ensures compatibility across diverse hardware platforms. Therefore, you should utilize this expansion board to overcome the hardware limitations of standard I2C communication in complex multi-sensor environments.

Key Features:

• 8-Channel Expansion: The board allows a single I2C master to control up to eight independent I2C downstream buses, effectively multiplying your connectivity options.
• Address Conflict Resolution: It solves the common problem where multiple identical peripherals share the same hard-coded I2C address.
• Voltage Level Translation: The integrated circuitry supports bi-directional voltage translation, facilitating safe communication between components operating at different logic levels.
• Programmable Control: Users can select active channels via the I2C bus itself, enabling dynamic switching through standard software libraries.
• Configurable Board Address: Three hardware address pins allow you to connect up to eight TCA9548A boards together, providing a total of 64 I2C channels.

Technical Specifications:

• Operating Supply Voltage: 1.65 V to 5.5 V
• I2C Speed Support: Standard (100 kHz) and Fast Mode (400 kHz)
• Interface Type: I2C (Serial Data SDA, Serial Clock SCL)
• Multiplexer Address Range: 0x70 to 0x77 (Selectable via A0, A1, A2 pins)
• Standby Current: ≈ 0.1 μA (Extremely low power consumption)
• Logic Level Compatibility: 1.8V, 2.5V, 3.3V, and 5V systems

Mechanical Specifications:

• Module Name: CJMCU-9548 / TCA9548A
• PCB Color: Purple or Blue (depending on production batch)
• Mounting Holes: Two M2-sized mounting holes for secure chassis attachment.
• Header Compatibility: Standard 2.54mm pitch pins for breadboard use.

Dimensions:

• Board Length: ≈ 31.5 mm
• Board Width: ≈ 21.4 mm
• Board Thickness: ≈ 1.6 mm
• Weight: ≈ 3.0 g (including headers)

Pinout and Wiring:

• VIN/GND: Connect to your system power supply and ground (3.3V or 5V).
• SDA/SCL (Master): Connect these to the main I2C pins of your Arduino, ESP32, or Raspberry Pi.
• RST (Reset): Active-low reset pin; pull this high for normal operation or toggle it to reset the bus.
• A0, A1, A2: Address selection pins used to change the board’s own I2C address (default is 0x70 when grounded).
• SD0-SD7 / SC0-SC7: Eight pairs of independent I2C channels for connecting your downstream devices.

Datasheet Reference:

• Download TCA9548A Official Datasheet

Commonly Used in:

• OLED Displays: Running multiple 0.96-inch OLEDs that often have fixed I2C addresses.
• Sensor Arrays: Managing multiple identical temperature (BME280) or light (BH1750) sensors in a single network.
• Robotics Control: Interfacing with numerous I2C-based motor drivers and TOF (Time of Flight) distance sensors.

Applications:

• Bus Isolation: Isolating a crashed I2C slave from the rest of the system to prevent a total bus hang.
• Logic Level Shifting: Bridging communication between a 3.3V microcontroller and 5V legacy sensors.
• Telemetry Systems: Collecting data from wide-scale sensor networks using a single master controller.

Equivalent Models:

• PCA9548A: A functionally identical multiplexer from NXP, however, verify voltage levels as some variants have slight differences in power requirements.
• TCA9544A: A 4-channel version of the same I2C multiplexer family for smaller projects.
• SparkFun Qwiic Mux: A similar board utilizing the same chip but featuring Qwiic/STEMMA QT connectors for solderless connectivity.

Package Includes:

• 1 x CJMCU TCA9548A I2C 8 Channel Multiple Extensions Development Board
• 2 x 12-Pin Header Set (Male)