BM70 Bluetooth® 4.2 Low-Energy (BLE)

Last modified by Microchip on 2024/02/07 10:19

The BM70 Bluetooth® 4.2 Low-Energy (BLE) module is designed for easy implementation into a broad range of applications including the 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.

BM70 Module

Additional features include:

  • Universal Asynchronous Receiver Transmitter (UART), I²C, and Serial Peripheral Interface (SPI) supported
  • Supports transparent UART data service of BLE
  • BM70 supports 3-channel Pulse Width Modulation (PWM)
  • Precision Temperature Sensor (PTS) with an 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

BM70 Block Diagram

MCU Interface

See the accompanying image that 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 on the BM70 MCU Interface page.

Connections required between the host microcontroller and the BM70 module

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.


Back to Top