u-blox Tackles Ails of Communication in Harsh Environments with Bluetooth 5 Module

December 19, 2019 by Gary Elinoff

The module is housed in a 7.5mm × 9.5mm × 1.5mm package and supports Thread and Zigbee.

u-blox has announced a new Bluetooth 5.0 module that features its own integrated-chip antenna. The new module incorporates Nordic Semiconductor’s nRF52840, a System on Chip (SoC) that has been described as "a multi-protocol SoC." 

The SoC includes a 64MHz Arm Cortex-M4 MCU with 256kB of RAM and 1MB of flash memory.



The BMD-380. Image (modified) used courtesy of u-blox


The BMD-380 joins u-blox’s BMD-3 series of Bluetooth low-energy devices. The device is a system on module (SoM) that enables Bluetooth low energy (BLE) 5 and IEEE 802.15.4 (Thread and Zigbee) connectivity for portable, extremely low-power embedded systems.

Integrating a 2.4GHz transceiver, the unit supports the LE 1M, LE 2M, and LE Coded (long-range) Bluetooth 5 PHYs.


Block diagram of BMD-380 BLE 5 SoC module

Block diagram of BMD-380 BLE 5 SoC module. Image (modified) used courtesy of (PDF) u-blox

The device can operate over a temperature range of –40°C  to +85°C.

The BMD-380 also features Arm’s TrustZone CryptoCell cryptographic unit. u-blox states that this unit will make it easier for engineers to implement the security features necessary in today’s vulnerable IoT environment.


Applications for the BMD-380

The BMD-380 is geared for a number of applications that require BLE 5 in a low-power system. In particular, u-blox states that the unit's long-range protocol makes it a useful option for communicating in harsh radio environments.

Other applications may include: 

  • IoT
  • Environmental monitoring
  • Wearables
  • Safety and security
  • Low-power sensor networks
  • Smart energy management
  • Interactive entertainment devices
  • Climate control
  • Home appliances
  • Lighting products
  • Access control
  • Home health care


Radio Performance

The BMD-380 operates over a frequency range of 2.360GHz to 2.500GHz. Employing GFSK modulation, data can be transmitted at 1Mbps or 2Mbps. With QPSK, the rate is 250Kbps. These complex modalities are described in further detail in Digital Phase Modulation: BPSK, QPSK, DQPSK.

The maximum transmit power is +8dBm, and in the BLE mode, receiver sensitivity is –96dBm. The internal antenna offers a maximum gain of –1dBi.


Power Requirements

u-blox also includes a DC-DC converter to enable the BMD-380 to be powered directly from its USB port from LiB cell.


Example of LV mode with USB and external regulator.

Example of LV mode with USB and external regulator. Image (modified) used courtesy of (PDF) u-blox

With the converter enabled:

Transmitting only: 14.8mA at +8dBm and 4.8mA at 0dBmm

Receiving only: 4.6mA at 1Mbps

CPU: 3.3mA


Supplied directly from VDD:

System off with no RAM retention: 0.4μA

System off with full 256KB RAM retention: 1.86μA, 2.35μA


Interfacing the BMD-380

This device, designed to be flexible, offers a multitude of interfacing options, including one or multiple: 

  • SPI 
  • Quad SPI 
  • UART 
  • I2C
  • GPIO x 44
  • I2S
  • PWM
  • PDM
  • USB 2.0
  • Analog I

The device features a pin multiplexing system that allows most internal peripherals, including the UART and SPI, to be used on any of the 44 GPIO pins. This option allows the designer to optimize his or her PCB layout.

However, it is only possible to multiplex one peripheral signal to a GPIO pin at a time. In addition, some functions are restricted to only certain pins.


Evaluation and Support Tools

u-blox offers the (PDF) BMD-380 evaluation development kit to speed up product development for OEMs.


BMD-380 evaluation board

The BMD-380-EVAL. Image from (PDF) u-blox


According to the datasheet, the evaluation board is said to "provide a complete I/O pin out to headers, on-board programming and debugging, 32.768 kHz crystal, power and virtual COM port over USB, BMD-380 USB connector, 64 Mb quad SPI Flash, four user LEDs, and four user buttons."


Around the Industry

The STM32WB series from ST is based on a 64MHz Arm Cortex‐M4 core as an application processor and a 32MHz Arm Cortex‐M0+ core for network processing. They support Bluetooth 5.0, ZigBee 3.0, and Openthread.

Cypress’s CYW20819 is a Bluetooth 5 single-chip solution targeted at Bluetooth mesh, wearables, gaming consoles, and other IoT applications. It includes an Arm Cortex-M4 core running at a maximum speed of 96MHz.