ET-A02
TCA9548A I²C Multiplexer
Eight separate I²C channels, each with its own Qwiic port
AED 22.00
Out of stockOverview
Eight separate I²C channels, each with its own Qwiic port
The ET-A02 is built around the TI TCA9548A — 8 independent downstream I²C channels, any combination on, 1.65–5.5V, voltage translation between channels. It talks over I²C 0x70 (0x70–0x77 via jumpers); Qwiic in/out + 8 Qwiic channel ports and runs from 1.65–5.5V; each channel powered from VIN.
Two Qwiic / STEMMA QT connectors let you chain it with other boards without soldering, and the 2.54 mm header fits a breadboard.
Designed in Dubai by ElectroTrical — the full schematic, BOM and design notes are published below.
Good for
- Several sensors with the same address
- Splitting long cable runs
- Mixed 3.3 V and 5 V buses
Key features
What makes it different
Switch
TI TCA9548A: 8 independent downstream I²C channels, any combination on, 1.65–5.5V, voltage translation between channels
Interface
I²C 0x70 (0x70–0x77 via jumpers); Qwiic in/out + 8 Qwiic channel ports
Supply
1.65–5.5V; each channel powered from VIN
Use
Same-address sensors on one bus (e.g. 8 × VL53L1X or 8 × SHT41)
Qwiic / STEMMA QT
Two JST-SH connectors plus a 2.54 mm header — 3.3 V and 5 V hosts.
Open documentation
Schematic, BOM and layout notes published for every board.
Specifications
Technical specifications
| Switch | TI TCA9548A: 8 independent downstream I²C channels, any combination on, 1.65–5.5V, voltage translation between channels |
|---|---|
| Interface | I²C 0x70 (0x70–0x77 via jumpers); Qwiic in/out + 8 Qwiic channel ports |
| Supply | 1.65–5.5V; each channel powered from VIN |
| Use | Same-address sensors on one bus (e.g. 8 × VL53L1X or 8 × SHT41) |
| Size | 63.5 × 25.4 mm |
|---|---|
| Mounting | 4 × M2.5 holes, 2.54 mm from each corner |
| Connectors | 2 × Qwiic / STEMMA QT (JST SH 4-pin) · 5-pin 2.54 mm header |
| Main IC | TCA9548APWR (LCSC C130026) |
| Revision | Rev A |
| Libraries | Adafruit TCA9548A examples, SparkFun I2C Mux library, CircuitPython adafruit_tca9548a |
|---|
| JP1 (default Closed) | Power LED (cut = off) |
|---|---|
| JP2 (default Closed) | I²C pull-ups (cut = off) |
| JP3–JP5 (default Open) | Bridge to set A0–A2 → address 0x70–0x77 |
Performance
Scale
Pinout
Pin map and connections
| Pin | Name | Type | Function |
|---|---|---|---|
| 1 | VIN | Power | 3.3–5V |
| 2 | GND | Ground | Ground |
| 3 | SCL | I²C | I²C clock |
| 4 | SDA | I²C | I²C data |
| 5 | RST | Control | Low = reset (pulled up) |
Qwiic / STEMMA QT pins: GND, VIN, SDA, SCL (same on both connectors). I²C pull-ups (10 kΩ) are on the board; cut JP2 to remove them.
Mechanical
Dimensions and what's in the box
In the box
- 1 × ET-A02 TCA9548A I²C Multiplexer (assembled)
- 1 × 5-pin 2.54 mm male header, unsoldered
Getting started
- Plug in a Qwiic / STEMMA QT cable, or solder the header and wire VIN, GND, SDA and SCL
- Libraries: Adafruit TCA9548A examples, SparkFun I2C Mux library, CircuitPython adafruit_tca9548a
- Run an I²C scanner to confirm the address: 0x70, 0x70, 0x77
Compare
Which I²C helper?
| TCA9548A I²C Multiplexer (this board)This board | ET-A01 Qwiic 5-Port Hub | ET-A08 Qwiic Breadboard Adapter | ET-A09 5V Arduino to Qwiic Adapter | |
|---|---|---|---|---|
| What it does | Eight separate I²C channels, each with its own Qwiic port | Split one Qwiic cable into five ports plus a header | Plug Qwiic boards into a breadboard or plain headers | Safe 3.3 V power and I²C levels for Qwiic on 5 V boards |
| Interface | I²C 0x70 (0x70–0x77 via jumpers); Qwiic in/out +… | — | — | — |
| Best for | Several sensors with the same address | Connecting several sensors at once | Using Qwiic sensors on any board | Qwiic sensors on Arduino Uno and Mega |
| Price | 22 AED | 9 AED | 9 AED | 23 AED |
Downloads
Documents and design files
Need a custom version of this board?
Different connector, size or sensor? We design and build custom variants.