Bluetooth LE home automation system allows wall switches to wirelessly control lights in mesh network

Nordic Semiconductor today announces that Phantom, a Beijing, China-based electronic lighting component manufacturer, has selected Nordic’s nRF52832 Bluetooth® Low Energy (Bluetooth LE) System-on-Chip (SoC) to provide the wireless connectivity for its End-device level Distributed Automation (ELDA) system. In an ELDA system, end-devices such as wall switches and lights can communicate with each other directly through a Bluetooth mesh network, eliminating the need for complex and costly electrical wiring and meeting the requirements for smart lighting manufacturers and home automation companies.

 

The ELDA system consists of two integrated products: the NVCM3-BT control device for LED drivers (which regulate the power supply for the LED lighting); and the SNP12-BT battery-powered device that converts a conventional wall switch into a wireless product. Both the NVCM3-BT and SNP12-BT products employ the nRF52832 SoC. The Nordic technology enables Bluetooth LE wireless connectivity between the wall switch and each LED driver.

 

The installed wireless wall switch is installed in a home or office and the LED driver control device is installed into each light to form a Bluetooth mesh network, the user then flicks the switch to activate the light in the mesh network without recourse to a central hub. Mesh networking ensures that if any individual light is out of Bluetooth LE range of the switch, another light will automatically pass the message on.

In addition, if a home user presses a button on a wireless wall switch panel to trigger a predefined lighting ‘scene’, Bluetooth mesh multicasting allows the message to be sent directly from the wall switch to the whole group of lights using the ELDA system. No central coordinator is required as each light is configured with the various predefined scenes (via a smartphone or gateway). Bluetooth mesh’s elimination of a central coordinator improves smart lighting robustness and reduces system latency.

 

While the ELDA system can operate without a gateway, Phantom offers a gateway to enables the smart lighting Bluetooth mesh to connect via Wi-Fi or Ethernet to the Cloud for remote control (via a smartphone) and energy use analysis. 

 

Nordic’s nRF52832 multiprotocol SoC combines an 64MHz, 32-bit Arm® Cortex® M4F processor with a 2.4GHz multiprotocol radio (supporting Bluetooth 5, ANT™, and proprietary 2.4GHz RF protocol software) featuring -96-dB RX sensitivity, with generous 512kB Flash memory to support Phantom’s over-the-air device firmware updates (OTA-DFU) and 64kB RAM which enables the chip to run the ELDA devices’ computationally-intensive applications. The SoC is supplied with Nordic’s S132 SoftDevice, a Bluetooth 5-certifed RF software protocol stack for building advanced Bluetooth LE applications. The S132 SoftDevice features Central, Peripheral, Broadcaster and Observer Bluetooth LE roles, supports up to twenty connections, and enables concurrent role operation.

 

The SNP12-BT wall switch device uses a CR2450 non-chargeable battery to achieve battery life of approximately five years or 300,000 push events, whichever comes first.

 

“Bluetooth LE plays the most significant role in extending battery life - a critical requirement in large-scale deployment of home and building automation systems,” says Wu Tianji, CTO at Phantom.

 

“Because we required multi-tasking, the Nordic SoC’s Zephyr RTOS [real-time operating system] support was also important. Nordic has a great reputation for making wireless transceivers and we have been using previous generations of Nordic SoCs for a number of years. And the company also provides good technical support, documentation, community, and open-source involvement.”