BM70 Overview

The BM70 Bluetooth® 4.2 Low-Energy (BLE) module is designed for easy implementation into a broad range of applications including Internet of Things (IoT), Payment/Security, Wearable Devices, Home and Security, Health and Fitness, among many others. When interfaced with a BLE enabled smartphone or Bluetooth Internet gateway, applications can be monitored, controlled, and updated from anywhere in the world. It conforms to the Bluetooth core specification version 4.2 to enhance throughput and security for IoT applications.

The BM70 module is built around Microchip Technology's IS1870/71 BLE System on Chip (SoC), which incorporates a Bluetooth stack, power management subsystem, 2.4 GHz transceiver, and RF power amplifier. The BM70 also supports Beacon technology to enhance the user experience for IoT applications and enables users to control the cloud and receive data without opening the application (typically through a smartphone). In addition, the BM70 can independently maintain a low power wireless connection which maximizes the module's lifetime in battery-operated devices.

Click image to enlarge.

Additional features include:

  • Universal Asynchronous Receiver Transmitter (UART), I²C, and Serial Peripheral Interace (SPI) supported
  • Supports transparent UART data service of BLE
  • BM70 supports 3-channel Pulse Width Modulation (PWM)
  • Precision Temperature Sensor (PTS) with operating range of -20 °C ~ +70 °C with an accuracy of +/- 3 °C
  • 12-bit (8 ch) Analog-to-Digital Converter (ADC) support for battery and voltage detection is provided
  • 18 General Purpose I/O (GPIO) pins
  • Integrated 32 MHz crystal
  • Small and compact surface mount module
  • Castellated Signal Measurement Timer (SMT) pads for easy and reliable PCB mounting

Block Diagram


MCU Interface

The picture below highlights the connections required between the host microcontroller and the BM70 module. It also shows several control and status functions that may be triggered by BM70 GPIO pins. These signals are described in detail in the BM70 MCU Interface page.


The BM70 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.


For the most up-to-date documentation, please visit the Microchip Website.

© 2024 Microchip Technology, Inc.
Notice: ARM and Cortex are the registered trademarks of ARM Limited in the EU and other countries.
Information contained on this site regarding device applications and the like is provided only for your convenience and may be superseded by updates. It is your responsibility to ensure that your application meets with your specifications. MICROCHIP MAKES NO REPRESENTATIONS OR WARRANTIES OF ANY KIND WHETHER EXPRESS OR IMPLIED, WRITTEN OR ORAL, STATUTORY OR OTHERWISE, RELATED TO THE INFORMATION, INCLUDING BUT NOT LIMITED TO ITS CONDITION, QUALITY, PERFORMANCE, MERCHANTABILITY OR FITNESS FOR PURPOSE. Microchip disclaims all liability arising from this information and its use. Use of Microchip devices in life support and/or safety applications is entirely at the buyer's risk, and the buyer agrees to defend, indemnify and hold harmless Microchip from any and all damages, claims, suits, or expenses resulting from such use. No licenses are conveyed, implicitly or otherwise, under any Microchip intellectual property rights.