Taking the Complexity out of Connectivity for IoT applications

However, before a wireless product can be put on the market, it needs to be certified, a process that can be fraught, complex, expensive and time consuming. Fortunately, wireless module and System-on-Chip (SoC) based solutions for BLE and other standards are now readily available, often complete with the required radio certifications. These solutions eliminate the need for radio design expertise for the integration as well as removing much of the qualification process allowing developers to concentrate their efforts on the features of the end device.

Nick Stone, Field Application Engineer at Anglia, introduces the portfolio of Bluetooth Low Energy (BLE) SoC and modules from STMicroelectronics which allow a much faster time-to-market and help make significant engineering cost savings.

Bluetooth Low Energy (BLE)
The Bluetooth wireless standard has become ubiquitous and is now familiar in a wide range of consumer applications from fitness bands through to handsfree phone integration in vehicles. Bluetooth Low Energy (BLE) is interoperable with classic Bluetooth and can communicate with smartphones and similar devices. It is also optimised for very low power allowing it to be integrated into battery powered applications such as IoT sensor nodes which demand long service life from a primary battery power source. This opens BLE to applications from which classic Bluetooth is excluded, such as Industrial (remote device configuration), Smart Home (sensor control and monitoring), Wearables and Hearables, enhancing and improving the user experience.

STMicroelectronics has a comprehensive offering for BLE. The STM32WB line of Microcontrollers offers integrated BLE application processors based on Arm® Cortex®-M4 core and BLE network processors based on the Arm CortexM0+ core. These processors are available as discrete devices, offering customers maximum design flexibility.

However, STMicroelectronics also offers these devices as pre-integrated modules, giving customers much easier integration and a greatly reduced qualification process. Also, for more streamlined applications, the lightweight BlueNRG portfolio from STMicroelectronics offers a spectrum of cost effective BLE 5.2 solutions from the basic network processor to single-core ultra-low-power Arm® Cortex®-M0+ Wireless SoC application processors and corresponding pre-certified modules giving designers greater flexibility to meet the demands of the application.

I will start by describing the processors in the STMicroelectronics range, and then go on to discuss the associated module options available.

Bluetooth Low Energy - System-on-Chip (SoC)
The STMicroelectronics BlueNRG range of SoC devices are available in four variants allowing users to select the right product according to their existing hardware architecture. The first and most basic of these is the BlueNRG-2N device which is a Network processor (external host required), this implementation allows designers to leverage software and minimize deployment risks, by just adding BLE functionality on top of an existing product via a basic UART or SPI-to-BLE bridge. More importantly, the dual-chip partitioning allows users to tailor the processing, memory and I/O requirements of the application by easily scaling MCU capabilities thanks to a decoupled radio sub-system.

The next two device families in the portfolio, BlueNRG-1 and BlueNRG-2 do not require an external processor to host the application as they come with and embedded  and fully programmable Arm® Cortex®-M0 with 160kB and 256kB of non-volatile memory respectively as well as fully featured I/O peripherals.

The fourth and most recent device, BlueNRG-LP, represents the 3rd generation of BlueNRG portfolio and offers an ultra-low-power SoC with best-in-class features of BLE 5.2 certified radio supporting up to 2Mbits/s (faster data transfer), Coded PHY (longer-range) and Enhanced Attribute Protocol, offering faster pairing capabilities, as well as lowest power consumption for longer battery life. The BlueNRG-LP SoC comes with 256kB of embedded non-volatile memory and is the most energy-efficient product in the portfolio.

The BlueNRG portfolio comes fully BLE 5.2 certified and is offered in various packages: QFN32, QFN48 with extended I/O capabilities or WLCSP for miniaturized and size constrained applications. Figure 1 provides a simple overview of the BlueNRG SoC portfolio.

Figure 1. BlueNRG SoC comparison

Bluetooth Low Energy - Modules

These devices form the centrepiece of the STMicroelectronics range of pre-certified BLE modules which greatly simplify connectivity adoption in every design. The Modules require no expertise in Radio Frequency and are ready-to-use products enabling wireless connected solutions.

STMicroelectronics family of BlueNRG Modules are Bluetooth SIG End-Product certified and have obtained pre-certification across major worldwide regions. The modules are suitable for operation in industrial environments up to +85 °C and are included in STMicroelectronics 10-year longevity program, this gives developers the confidence to design the BlueNRG modules into industrial applications which have typical service lives of many years, often decades, without the issue of expensive and time-consuming regular hardware redesigns. The BlueNRG modules are available in two variants, the BlueNRG-M0 (network processor) and BlueNRG-M2 (programmable SoC with featured I/O peripherals).

The BlueNRG-M0 modules are built around the BlueNRG-MS network processor chip, they provide an easy-to-use Bluetooth low energy master/slave network processor module, compliant with Bluetooth v4.2. The BlueNRG-M0 module supports multiple roles simultaneously and can act at the same time as Bluetooth low energy sensor and hub device.

The entire Bluetooth low energy stack and protocols are embedded into BlueNRG-M0 module, the external host application processor, where the application resides, can be connected to the BlueNRG-M0 module through a standard SPI interface.

The BlueNRG-M2 modules are a Bluetooth Low Energy system-on-chip application processor certified module, compliant with Bluetooth specifications v5.2 and BQE qualified. The BlueNRG-M2 module supports multiple roles simultaneously and can act at the same time as Bluetooth master and slave device.

The modules embed the entire Bluetooth low energy stack and protocols and do not require an external processor to host the application reducing the demand on the host system processor.

The BlueNRG-M2 is based on the BlueNRG-2 system-on-chip featuring a high performance, ultra-low power Cortex-M0 32-bit based core with programmable embedded 256 kB Flash and 24 kB embedded RAM with data retention. The module can deliver up to +8 dBm output power (Tx), receive (Rx) sensitivity down to -88 dBm and up to 96 dB link budget with excellent link reliability.

The BlueNRG-M0 and BlueNRG-M2 modules provide a complete RF platform in a tiny form factor measuring just 13.5 x 11.5mm with a low-profile height of just 2.5mm max. Bluetooth Radio, embedded antenna and high frequency oscillators are integrated into the modules to offer a certified solution that optimizes the time-to-market of the final applications. Both modules can be powered directly with a pair of AAA batteries or any power source from 1.7 to 3.6 V, and in the case of the BlueNRG-M0 directly from a standard 3 V coin cell battery.

Design Support
To assist designers, STMicroelectronics have developed a comprehensive suite of hardware evaluation kits, software development kits (SDK) and PC tool ecosystem. These easy-to-use tools allow designers to evaluate the full capabilities of the BlueNRG portfolio of Bluetooth Low Energy SoC devices and Modules.

An example of this is the BlueNRG Navigator, which is an “out-of-the-box” solution that has a Graphic User Interface that provides a simple and user-friendly interface to browse, flash, and run application examples included in the SDK package.

To further ease developers and enable fast adoption the whole product family is supported by leading edge 3rd parties Integrated Development Environment as well as STMicroelectronics free-of-charge and multi-platform Wireless Software Environment (WiSE).

Also, STMicroelectronics is offering a BT SIG certified Bluetooth Mesh protocol stack capable to extend BLE adoption to applications requiring unlimited networking of multiple wireless nodes, such as appliances or sensors for the smart-home as well as lighting solutions for smart-building or industrial applications.

There are also easy to use BlueNRG applications available on both Google Play and the Apple store which can be used with the various evaluation tools. Furthermore, there are PC utilities for features such as the radio initialization wizard, power consumption control/monitoring along with a flasher and ST-Link utility.

The tools provide a set of hardware and software resources for a wide range of application scenarios such as sensor data (accelerometer, pressure and temperature sensors), remote control (buttons and LEDs) and debug message management via USB virtual COM.

The boards can be powered by USB only, battery only and external power supply plus USB for application development and testing flexibility.

Anglia offer support for customer designs with free evaluation kits, demonstration boards and samples of STMicroelectronics products via the EZYsample service which is available to all registered Anglia Live account customers.

Anglia’s engineering team are also on hand to support designers with their extensive experience of wireless designs and can offer advice and support at component and system level. This expertise is available to assist customers with all aspects of their product design, providing hands on support and access to additional comprehensive STMicroelectronics resources including technical application notes and reference designs.

Summary
Whilst wireless connectivity can be a complex field, the BlueNRG Bluetooth Low Energy solutions from STMicroelectronics make Bluetooth integration into the end application a breeze whether you opt to use the SoC or certified Module based products. Furthermore, the BlueNRG portfolio is backed up with comprehensive hardware and software support tools that enable designers to get up and running in no time, and more importantly help accelerate the critical time-to-market.

And to re-iterate their commitment to supporting industrial designs, the BlueNRG portfolio is part of STMicroelectronics product longevity program which guarantees they will remain in mass production for 10 years from the product introduction date. This gives industrial product designers the confidence to integrate them into their applications knowing the parts will not be discontinued in a short space of time.

Visit www.anglia-live.com to see the full range of STMicroelectronics products available from Anglia.