The BMB81TM01A is an IoT expansion board built for the micro:bit ecosystem and can be stacked directly with the BBC micro:bit. It reorganizes the micro:bit’s GPIO, I²C, UART, and other signals into HY2.0 fool-proof connectors, enabling users to connect sensors and modules more quickly while reducing wiring errors and the time spent searching for pin definitions.

The board integrates a BW16 wireless module with dual-band Wi-Fi and BLE 5.0 support, eliminating the need for additional wireless add-ons. It is suitable for common IoT scenarios such as data uploading, remote monitoring, and smartphone/tablet control. Combined with the visual programming tools or Python commonly used in the micro:bit ecosystem, both beginners and advanced developers can get started easily.

In educational settings, the BMB81TM01A supports a wide range of activities—from basic electronics and sensor projects to advanced IoT applications. For makers and engineering development, it serves as a bridge between the micro:bit and Best Modules’ HY2.0 ecosystem, providing stable power delivery and an organized interface layout for a smoother development experience.

1. Direct plug-in support for the micro:bit
   - Connects via gold-plated edge connector, no pin headers required
   - Ready to use; retains micro:bit functionality while expanding external I/O ports
2. Built-in wireless module: BW16 (Wi-Fi + BLE 5.0)
   - Supports 2.4GHz / 5GHz dual-band Wi-Fi
   - BLE 5.0 support for IoT data transmission and mobile control
3. HY2.0 fool-proof connector design
   - Reorganizes micro:bit digital / analog / communication pins into HY2.0 ports
   - Plug-and-play design reduces the use of jumper wires and wiring mistakes
4. Rich communication and expansion interfaces
   - I²C × 3 (3.3V logic level)
   - UART × 3 (3.3V logic level)
   - 3-PIN × 8 for sensors and actuators
5. Power input and power management
   - Supports USB Type-C 5V input or DC 5V–24V wide-range input
   - Integrated DC/DC buck power circuitry provides stable 3.3V output
   - Up to 1.5A total 3.3V output current for driving multiple modules
6. UART1 / Wi-Fi DIP-switch selection
   - DIP switch toggles the function of P0 / P1 pins
   - Choose between connecting to the BW16 module or the external UART1 interface
7. Compatible with Best Modules HY2.0 and BMduino series
   - Directly supports Best Modules HY2.0 sensors, displays, communication modules, etc.
   - Modules can also be used with the Arduino ecosystem, ideal for shared classroom resources
8. Suitable for IoT education, maker projects, interactive installations, and IoT development
9. Dimensions: 82.0 × 82.0 × 15.0 mm