Ultra low power semiconductors scale up IoT sensing

Offices, restaurants, factories, and opera houses are just a few examples where miniature IoT sensors – capable of measuring temperature, humidity, space occupancy, and many other useful parameters – are proving to be a game changer for operators. The technology allows users to monitor fresh air in meeting rooms, schedule cleaning and maintenance, warn if commercial fridges and freezers have failed, and perform many other business-critical tasks.

15-year battery life

A revolution in IoT sensing has been promised for a while, but what’s making it possible today is the rise of ultra low power electronics that give wireless sensors a battery life as long as 15 years. “We developed ASICs to control the sensors and provide power management,” Øystein Moldsvor, Co-founder and VP of Engineering at Disruptive Technologies, told TechHQ. “And they enable electronics that consume just a few nanoamps of current.”

Reducing the energy footprint of IoT sensors opens the door to much larger deployments. Today, operators can focus their efforts on benefiting from the data rather than worrying about changing batteries. Besides the electronics, the design of the communications protocol also plays an important role in keeping power consumption low. And while specifications such as Zigbee and BluetoothLE allow devices to run for longer, they still have trade-offs within their designs as the protocols are trying to appeal to all use cases.

Recognizing that there were further energy-saving opportunities left on the table, Moldsvor, and his colleagues, who have backgrounds in the semiconductor industry, leveraged their expertise in wireless microcontrollers. “The protocol and encryption system is optimized to improve the sensor lifetime,” Moldsvor explains, which brings our discussion neatly to the topic of security.

End-to-end encryption

In conventional IoT systems, the hubs or gateways that gather data from end-points and send the information to the cloud can represent a target for so-called ‘man in the middle’ attacks. Aware of this threat, Disruptive Technologies takes security a step further and, in effect, pairs its sensors directly with users. At the point of manufacture, each sensor is assigned a unique 256-bit asymmetric encryption key, which facilitates the creation of a tamper-proof, end-to-end encrypted communication channel. The solution is proof that security can still be enabled even on power-constrained devices. “Encryption costs a little bit of energy to setup, but it’s not a major drain on the device,” said Moldsvor.

Having covered-off low power consumption and put security measures in place, the other critical element in the design story is making sensors that are easy to set up and use. Each device, which can measure as small as 19 mm square and just 2.5 mm thick, features a QR code that allows users to quickly add the sensor to their account. And with the details now on the system, the discovery protocol enables the device to be readily identified on the network.

Moldsvor points out that a small team can easily install 1000 sensors in day, and devices are supplied with an adhesive backing to simplify mounting. What’s more, even though battery chemistry is designed for room temperature, the low-power characteristics of the sensing electronics mean that devices still remain functional at conditions as low as -40 degC. Customers include food warehouse operators, who place temperature sensors inside freezers. In the IT sector, devices can be stuck against server cabinets to keep an eye on heating and cooling, and monitor for any leaks in the system. The list of applications huge and, in many ways, is only limited by the imagination of the end users – for example, sensors can be cable-tied to pipes to keep track of water temperature, a deployment that has saved hundreds of thousands of litres of water at offices in London, UK.

Data studio

To make it easy for users to access their data, as well as set-up notifications and alerts, the team has designed a web-app to accompany the devices. The software provides a variety of dashboard views, and data can be integrated with other packages such as Microsoft’s Power BI. To do this, customers can use data connectors that forward information from the cloud to an external database in real-time. Other visualizations include heat maps, which can be built using Python and animated to give valuable building information, for example.

The best way to discover what IoT sensing can do for your business is to get hands-on with the technology – for example, by picking up a starter kit and putting the devices to the test. Customers have found numerous ways to automate reporting tasks and gather facilities data to better understand how buildings are being used. Live information can help to optimize heating and cooling, to save on energy bills, and to prevent food waste. Carbon dioxide sensors can be integrated into intelligent building ventilation systems to adjust airflow to ensure much more comfortable and pleasant working environments.

Smart buildings are well suited to new models of working, where office occupancy can be much harder to predict. Sensing data allows facilities managers to deploy only the services that are required at the time, and use resources much more efficiently.