Modules for the Edge
Connecting to the IoT edge requires highly integrated technology, blending wireless connectivity and intelligence. Feeding those needs, a variety of IoT modules have emerged that offer pre-certified solutions that are ready to use.
By Jeff Child, Editor-in-Chief
he Internet of Things (IoT) is one of the most dynamic areas of embedded systems design today. Opportunities are huge as organizations large and small work to develop IoT implementations. IoT implementations are generally comprised of three main parts: the devices in the field, the cloud and the network (gateways) linking them together. This article focuses on the “things” side—in other words, the smart, connected edge devices of the IoT. For more on IoT gateways, see “IoT Gateway Advances Take Diverse Paths“ (Circuit Cellar 328, November 2017).
Because this sub-segment of technology is growing and changing so fast, it’s impossible to get a handle on everything that’s happening. The scope that comprises IoT edge devices includes a combination of embedded processors and microcontrollers that provide intelligence. It also includes various wireless, cellular and other connectivity solutions to connect to the network. And it includes sensors to collect data and battery technologies to keep the devices running.
Connecting the various nodes of an IoT implementation can involve a number of wired and wireless network technologies. But it’s rare that an IoT system can be completely hardwired end to end. Most IoT systems of any large scale depend on a variety of wireless technologies including Wi-Fi, Bluetooth, Zigbee and even cellular networking.
What’s most interesting among all that, are not those individual pieces themselves, but rather an emerging crop of modular IoT products that combine intelligence and connectivity, while also taking on the vital certifications needed to get IoT implementations up and running. With all that in mind, the last 12 months have seen an interesting mix of module-based products aimed directly at IoT.
Certified IoT Modules
Exemplifying those trends, in September 2017, STMicroelectronics (ST)introduced the SPBTLE-1S, a ready-to-use Bluetooth Low Energy (BLE) module that integrates all the components needed to complete the radio subsystem (Photo 1). The BLE module integrates ST’s proven BlueNRG-1 application-processor SoC and balun, high-frequency oscillators and a chip antenna.
Developers can use this module to bypass hardware design and RF-circuit layout challenges. The SPBTLE-1S is BQE-approved, and FCC, IC and CE-RED (Radio Equipment Directive) certified to simplify end-product approval for North America and EU markets. ST’s Bluetooth 4.2 certified BLE protocol stack is included, and the supporting Software-Development Kit (SDK) contains a wide range of Bluetooth profiles and sample application code.
The device is packaged in a space-efficient 11.5 mm x 13.5 mm outline and has a wide supply-voltage range of 1.7 V to 3.6 V. The SPBTLE-1S module is well suited for small, battery-operated objects powered by various types of sources such as a primary button cell or rechargeable Li-ion battery. High RF output power of +5 dBm and good receiver sensitivity help to maximize communication range and reliability.
The BlueNRG-1 SoC at the heart of the SPBTLE-1S implements the complete BLE physical layer (PHY), link layer and network/application-processing engine comprising a low-power ARM Cortex-M0 core with 160 KB flash, 24 KB RAM with data retention and a security co-processor. The SoC also implements smart power management, with a DC/DC converter capable of powering the SPBTLE-1S module to ensure optimum energy efficiency. Users can leverage an extensive set of interfaces, including a UART, two I²C ports, SPI port, single-wire debug and 14 GPIOs, as well as peripherals including two multifunction timers, a 10-bit ADC, watchdog timer and real-time clock and a DMA controller. There is also a PDM stream processor interface, which is ideal for developing voice-controlled applications.
IoT Module for Development
Riding the IoT wave, all the major microcontroller vendors have beefed up their module-based IoT solutions in order to make it easier for developers to design in their MCUs. One example along those lines is the LPC54018 IoT module, developed by NXP in partnership with Embedded Artists. …
Read the full article in the March 332 issue of Circuit Cellar