The IoT embraces many products, technologies and applications. However, in terms of numbers of units, the largest segments of the IoT market will comprise small portable or wearable electronic devices that derive power from tiny batteries, or perhaps from energy harvesting. Many of these devices will gather sensor data which is processed then sent to the Internet via an access node or gateway, using one or more wireless protocols as the first part of the link.
There is much debate around which wireless protocols are likely to dominate in the IoT world. However, most industry observers expect Bluetooth® Smart to be the protocol of choice in many instances, not least for consumer products where many Internet connections will be made via a smartphone gateway. Smartphones, set-top boxes, televisions and a host of other consumer electronic products already incorporate Bluetooth radios, and Bluetooth Smart is both lower power and more secure than Wi-Fi. Analyst IHS predicts that by the end of 2015 every mobile platform will ship with Bluetooth Smart Ready functionality.
Semiconductor innovation is focused on reducing the energy consumption of sensors, processors and radios, whilst maintain sufficient processing power and radio performance for the required tasks. ARM® Cortex® M0 type processors are typically used in Bluetooth Smart ICs.
Functional integration is a key strategy for minimizing power consumption. If the baseband processor in a Bluetooth radio has sufficient resources to run the application too, this not only minimizes the size of the solution but also its cost and energy consumption. Of course, integration must go hand-in-hand with effective power management. The on-chip resources needed for each specific task must only be fully powered when they’re needed. It’s even possible to ‘tune’ a processor so that its clock speed, and hence performance, is controlled dynamically in line with the performance needed at the time.
Dialog Semiconductor designs and manufactures SmartBond™ Systems-on-Chip (SoCs). These tiny, ultra low power Bluetooth Smart components integrate a Bluetooth low energy radio with an ARM® Cortex®-M0 application processor and intelligent power management. Measuring just 2.5 mm x 2.5 mm in a WLCSP they need just five external components for a complete hosted Bluetooth Smart solution. Access to the ARM® processor is available via 32 GPIOs. Energy requirements are so modest that one company developed a smart insulin injection pen for diabetics where removal and replacement of the pen’s cap produces sufficient energy for the SmartBond SoC to capture the exact dose of insulin delivered and send that information to a smartphone app.
The SmartBond product family has recently been expanded to include a version with on-chip flash, the DA14583, which enables end products to be upgraded in the field using Software Upgrades Over The Air (SUOTA). There are also two new application-optimised variants: the DA14581 for loosely coupled, highly resonant inductive charging based on the A4WP standard, and the DA14582 for Bluetooth Smart remote control units (RCUs). The DA1582 integrates an analogue audio codec and is optimized for remote control units that use voice recognition, motion control or gesture recognition.
The latest device in the SmartBond family, the DA14680, takes functional integration even further, adding tunable processing power, dedicated circuitry for sensor control, and analogue and digital peripherals optimised for wearables. It’s effectively a ‘wearable-on-chip’ and it will be fascinating to see how it unleashes the creativity of consumer product designers with its ease of implementation, tiny size and minimal power requirements.
Dialog Semiconductor’s ‘Wearable-on-Chip™’ – the DA14680 Bluetooth Smart (v4.2)