Nordic-powered Bluetooth LE smart lock reimagines the home entry experience

An Apple HomeKit®- and Amazon Sidewalk-compatible smart lock that can be retrofitted onto almost any existing door has been launched by California-based company Level Home. The Bluetooth® Low Energy (Bluetooth LE) ‘Level Lock’ is powered by Nordic’s nRF52840 Bluetooth 5.2/Bluetooth LE advanced multiprotocol System-on-Chip (SoC) and enables instant and secure keyless entry to authorized users. 

Constructed from a combination of stainless steel and strengthened metal alloys, Level Lock has a compact profile made possible in part by the Nordic SoC’s compact 7 by 7mm footprint. The lock meets the highest industry standard for security, durability and reliability and is AAA certified by the Builder’s Hardware Manufacturers Association (BHMA). 

Advanced security features

In operation, the smart lock is paired to a user’s Bluetooth 4.0 (or later) smartphone using Bluetooth LE. From the ‘Level Home’ app users can then automatically lock and unlock their door without the need for a physical key, and send digital keys to authorized guests, for example a tradesperson, friend or babysitter. From the app, users can also set specified entry periods for guests with a ‘Party Pass’ feature, create a single event pass for multiple people to use, as well as view a record of the smart lock’s activity. 

The Nordic nRF52840 SoC incorporates an Arm TrustZone CryptoCell™-310 cryptographic module and an AES 128-bit hardware accelerator. These features support a wide range of asymmetric, symmetric and hashing cryptographic services for secure applications, and support Level Lock’s security requirements for the unlocking process. Alternatively the smart lock also supports key-, keycard- or touch-based (‘Level Lock – Touch Edition’) unlocking.

HomeKit and Sidewalk compatible

Nordic-powered Apple HomeKit and Amazon Sidewalk compatibility provides the user remote connectivity to Level Lock via HomeKit hub or Sidewalk-enabled devices. The ability to connect to other Apple, Amazon, as well as third party smart home devices allows consumers to perform ‘automations’ or create linked events, for example turning off lights or activating security cameras once the door has been locked.

The Level Lock is powered via a single Li/MnO2 battery, providing up to one year of battery life in typical use, thanks in part to the ultra low power operating characteristics of the nRF52840. The SoC has been engineered to minimize power consumption with a fully-automatic power management system that reduces power consumption by up to 80 percent compared with Nordic’s nRF51 Series. 

Nordic’s nRF52840 advanced multiprotocol SoC combines a 64MHz, 32-bit Arm® Cortex® M4 processor with floating point unit (FPU), with a 2.4GHz multiprotocol radio (supporting Bluetooth 5.2, Long Range, Bluetooth mesh, ANT™, Thread, Zigbee, IEEE 802.15.4, NFC, and proprietary 2.4GHz RF protocol software), featuring 8dBm output power -95dBm RX sensitivity for a link budget of 103 dBm, with 1MB Flash memory and 256kB RAM. The Dynamic Multiprotocol feature uniquely supports concurrent wireless connectivity of the protocols. The SoC features 12Mbps Full Speed USB.

The nRF Connect SDK [Software Development Kit] is recommended for nRF52840 software development. The nRF Connect SDK integrates the Zephyr RTOS, supports applications using Bluetooth LE, Bluetooth mesh and Thread, and includes examples, Bluetooth LE profiles and driver support for all peripherals. The SDK also includes a migration of Nordic’s Bluetooth SoftDevice Controller from the company’s proven SoftDevices used with the nRF52 Series. The nRF5 SDK can also be used for development with Nordic’s S113, S132 and S140 SoftDevices Nordic’s Bluetooth RF protocol stacks.

“The nRF52840 is a super versatile SoC that checked all the boxes for us and provided multiprotocol support,” says Ken Goto, co-founder and CTO of Level. “We were highly constrained in terms of physical space and power consumption, so the SoC footprint for its performance capabilities and available GPIOs was a great match. It had more than enough CPU performance to support our encryption needs, enabled us to add new protocols without changing the hardware platform, and helped introduce an entirely new smart home entry design and experience.”

• About Level Home
• About nRF52840
• About Nordic Semiconductor