Versatile Bluetooth LE smart lock offers Apple HomeKit and Xiaomi Mijia compatibility for broad smart home ecosystem support

Nordic Semiconductor today announces that Shenzhen, China-based Lumi United Technology, a member of smartphone and electronics giant Xiaomi’s ecosystem of companies, has selected Nordic’s nRF52840 Bluetooth® 5.2/Bluetooth Low Energy (Bluetooth LE) advanced multiprotocol System-on-Chip (SoC) to provide the wireless connectivity for its ‘Aqara Door Lock N200’.  

 

The smart door lock enables instant keyless door entry for multiple authorized users in domestic security applications. Once installed, the Aqara Door Lock N200 can be paired to the user’s Bluetooth 4.0 (and later) smartphone or tablet and set up and operated from either the iOS- and Android-compatible Xiaomi ‘Mi Home’ app or the iOS-compatible ‘Apple Home’ app. Bluetooth LE connectivity between the smartphone and door lock is provided by the nRF52840 SoC. From the app users can configure the lock settings and remote alarms, add/delete/update user information, remotely monitor the status of the lock, review a history of when the lock has been opened, and receive push notifications in the event the lock is abnormally tampered with, or if the door has not been properly locked.

The Nordic 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, underpinning the security of the Aqara Door Lock N200 unlocking process. Alternatively, the smart lock supports Near Field Communication (NFC), fingerprint, password and temporary password, and emergency key unlocking.

 

Apple HomeKit and Xiaomi Mijia compatibility allows the user to connect the smart lock to other Apple, Xiaomi as well as third-party smart home devices and perform linked events. For example, turn off the lights and activate the security camera as soon as the door is locked.

 

The Aqara Door Lock N200 employs eight AAA batteries and provides up to 18 months of battery life before replacement in standard operation, thanks in part to the ultra low power characteristics of the Nordic SoC. The nRF52840 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 the nRF51 Series.

 

Nordic’s nRF52840 is Nordic’s most advanced ultra low power nRF52 Series SoC. The SoC supports complex Bluetooth LE and other low-power wireless applications that were previously not possible with a single-chip solution. The nRF52840 is Bluetooth 5.2-, Thread 1.1-, and Zigbee PRO (R21) and Green Power proxy specification-certified and its Dynamic Multiprotocol feature uniquely supports concurrent wireless connectivity of the protocols. The 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, ANT™, Thread, Zigbee, IEEE 802.15.4, and proprietary 2.4GHz RF protocol software) with 1MB Flash memory and 256kB RAM. A new radio architecture with on-chip PA provides features -95-dBm RX sensitivity (at 1Mbps Bluetooth LE), a maximum output power of 8dBm, and a total link budget of 103dBm. The chip supports all the features of Bluetooth 5.2 (including 4x the range or 2x the raw data bandwidth (2Mbps)) compared with Bluetooth 4.2.

 

The SoC is supplied with Nordic’s S140 SoftDevice, a Bluetooth 5-certified software protocol stack for building long range and high data Bluetooth LE applications. The S140 SoftDevice offers concurrent Central, Peripheral, Broadcaster, and Observer Bluetooth LE roles, and supports high throughput and long range modes as well as advertising extensions. 

 

“Bluetooth LE was the preferred wireless protocol for the Aqara Door Lock N200 because it provides fast, stable configuration for users without the need for Wi-Fi connectivity,” says Dachuan Zhou, Senior Product Manager, Lumi United Technology.

 

“We selected the nRF52840 SoC because of its ability to run Bluetooth LE and its Apple HomeKit compatibility. Nordic’s SoftDevice architecture is also a major advantage because it allowed us to significantly reduce the size of the device’s firmware.”