GPIO Expander (Micro Relays) (Wi-Fi & Bluetooth)

Wi-Fi & Bluetooth GPIO Expander: The Ultimate IoT Command Center

Never run out of pins again. When your smart home or automation project scales up, standard microcontrollers quickly hit their limits. Whether you are building a custom master control panel with dozens of push-buttons, triggering an array of micro relays for lighting zones, or monitoring a massive sensor network, wiring multiple expansion breakout boards is a nightmare.

The GPIO Expander Board solves the pin-shortage problem instantly. By pairing a powerful ESP32 with a dedicated 16-bit I/O expander, this board gives you massive control capacity and native wireless connectivity on a single, clean PCB.

🎛️ Massive Expansion: 16-Bit I/O & Micro Relay Control

Driven by the rock-solid TCA9539A expander over a simple I2C bus, this board is built to handle complex arrays of inputs and outputs without bogging down your processor.

• 16 Extra Parallel Pins: Instantly expand your digital footprint. Perfectly suited for driving banks of micro relays, massive LED arrays, or monitoring rows of limit switches and sensors.
• Hardware Interrupts (INT): The secret weapon for efficient IoT. The dedicated INT pin triggers the moment any input changes state, meaning your code doesn't have to waste CPU cycles constantly polling for button presses.
• Fast & Reliable: Supports both I2C Standard mode (100 kHz) and Fast mode (400 kHz), with a dedicated RESET pin to easily return your hardware to its default state.

🌐 The Brain: Dual-Core ESP32 for Seamless IoT

At the core of the board is the Espressif ESP32-WROOM-32E, giving your expanded pin-array instant access to the network.

• Always Connected: Native Wi-Fi (802.11 b/g/n) and Bluetooth (Classic + BLE) make it incredibly easy to link your physical switches and relays directly to Home Assistant, custom dashboards, or remote servers.
• Heavy-Duty Processing: Two 32-bit LX6 Xtensa MCUs and 4 MB of flash memory ensure your complex automation logic runs smoothly.
• Bonus Sensors: Includes an integrated 3-axis gyroscope, 3-axis accelerometer, and temperature sensor built right onto the board for added environmental awareness.

💻 Frictionless Software Integration

We handle the complex I2C addressing so you can focus on building.

• Plug and Play: Standard 0.1” header spacing means it drops perfectly into your breadboard. Feel free to utelize our schematic and BOM.
• Arduino IDE Ready: Fully supported within the Arduino ecosystem for quick C++ development.
• MicroPython Compatible: Prefer Python? Flash it and use the Thonny IDE for rapid scripting and utelize our API which can be found here.
• Tested Example Code: Don't start from scratch. Access our dedicated GitHub repository for copy-paste-ready code snippets, wiring diagrams, and project inspiration.

🔧 Included

• Board with mounting holes (mounting holes can be broken off if desired - see image)
• Standoffs & Screws (see image)
• Headers (see image)

Scale your project without scaling your wiring footprint.