TCA9548A 8-Channel I²C Multiplexer Breakout Arduino / ESPHome Compatible

The TCA9548A is an 8-channel I²C multiplexer that allows multiple I²C devices with the same address to be connected to a single microcontroller. This is essential for advanced sensor arrays, robotics, weather stations, and large data acquisition projects.

✨ Features

• 8 independent I²C channels (CH0–CH7)
• Works at 3.3 V or 5 V logic levels
• Selectable I²C address via address jumpers (A0–A2)
• Compatible with Arduino, ESP8266, ESP32, and Raspberry Pi
• Fully supported by Arduino IDE, Adafruit libraries, and ESPHome YAML

📦 Package Includes

• 1 × TCA9548A 8-Channel I²C Multiplexer Module
• 1 × 2.54 mm header pin strip (may require soldering)
• 1 × Wiring Diagram (see below)

🔌 Wiring Diagram

Wiring summary: Connect VCC to 3.3 V (ESP8266) or 5 V (Arduino), GND to ground, SDA → A4 (Arduino) or D2 (ESP8266), and SCL → A5 (Arduino) or D1 (ESP8266). Each channel (CH0–CH7) connects to an independent I²C bus.

// Example: Using Adafruit_TCA9548A with Arduino

#include <Wire.h>
#include <Adafruit_TCA9548A.h>
#include <Adafruit_BME280.h>

Adafruit_TCA9548A tca = Adafruit_TCA9548A();
Adafruit_BME280 bme;

void setup() {
  Serial.begin(115200);
  Wire.begin();
  tca.begin();

  for (uint8_t i = 0; i < 8; i++) {
    tca.openChannel(i);
    if (bme.begin(0x76)) {
      Serial.print("BME280 found on channel ");
      Serial.println(i);
    }
    tca.closeChannel(i);
  }
}

void loop() {
  for (uint8_t i = 0; i < 8; i++) {
    tca.openChannel(i);
    Serial.print("Channel "); Serial.print(i);
    Serial.print(": Temp = ");
    Serial.println(bme.readTemperature());
    tca.closeChannel(i);
    delay(1000);
  }
}
  

i2c:
  sda: D2
  scl: D1
  scan: false

tca9548a:
  - id: mux0
    address: 0x70

sensor:
  - platform: bme280
    temperature:
      name: "BME280 Temp CH0"
    address: 0x76
    i2c_id: mux0
    channel: 0

  - platform: bme280
    temperature:
      name: "BME280 Temp CH1"
    address: 0x76
    i2c_id: mux0
    channel: 1
  

🧠 Typical Uses

• Multiple identical I²C sensors (e.g. several BME280 or MPU6050 modules)
• Smart greenhouse or weather station sensor arrays
• Robotics and automation systems with modular I²C subsystems
• Data acquisition and logging projects
• Educational and lab environments for I²C experimentation

⚙️ Specifications

• Operating Voltage: 3.3 V–5 V
• I²C Address Range: 0x70–0x77 (selectable by A0–A2 jumpers)
• Channels: 8 (CH0–CH7)
• Logic Level: 3.3 V / 5 V compatible

📦 Shipping & Returns

Ships within 1 business day. Free UK shipping or low-cost international delivery. Returns accepted 

Need multiple units for a project or classroom? Message for bulk pricing!