BM71 Bluetooth 4.2 Low-Energy Module

Last modified by Microchip on 2023/11/10 11:11


The BM71 is a small form factor, Bluetooth 4.2 Low-Energy module measuring only 9 x 11.5 x 2.1 mm. The BM71 module is designed for easy implementation into a broad range of applications. Supporting the latest Bluetooth® standard, it delivers up to 2.5x throughput improvement and more secure connections vs. Bluetooth 4.1 based products. Developers can easily interface to the device via a standard UART interface, available on most microcontrollers and processors.

The BM71 has a completely integrated Bluetooth software stack and offers a shielded regulatory-certification with a built-in antenna. Developers are freed from the complexities of Bluetooth Software and RF development and can simply utilize the BM71 as a wireline replacement. Perfect for IoT (Internet of Things) applications, when interfaced to a BLE-enabled smartphone or Bluetooth Internet Gateway, applications can be monitored, controlled, and updated from anywhere in the world.

BM71 Module

Additional features include:

  • UART, I2C, and SPI interface supported
  • Supports transparent UART data service of BLE
  • BM71 supports 1-channel PWM
  • Precision Temperature Sensor (PTS) with operating range of -20 °C ~ +70 °C with an accuracy of +/- 3 °C
  • 12-bit (5 ch) Analog-to-Digital Converter (ADC) support for battery and voltage detection
  • Nine general-purpose I/O pins
  • Integrated 32 MHz crystal
  • Small and compact surface-mount module
  • Castellated SMT pads for easy and reliable PCB mounting

Block Diagram

BM71 Block Diagram

MCU Interface

The image below highlights the connections required between the Host microcontroller and the BM71 module. It also shows several control and status functions that may be triggered by BM71 GPIO pins. These signals are described in detail on the "BM71 MCU Interface" page.

MCU Interface Connection Diagram

The BM71 UART pins, HCI_TXD and HCI_RXD, are connected to the UART pins of the host MCU. All module control and status may be obtained via specially formatted packets sent/received via UART TX/RX signals.

Application Examples

Visit the BM71 Applications Examples page for links to detailed instructions on how to get started with the BM71 module


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