STMicroelectronics bases smart building KNX-RF software on S2-LP transceiver
For power-conscious building automation, the KNX software by STMicroelectronics is for its S2-LP ultra-low-power radio transceiver to enable energy-saving standardised wireless connectivity for smart building controls.
The software runs on an STM32 microcontroller or a BlueNRG-2 Bluetooth Low Energy SoC with an Arm Cortex-M0 core running at 32MHz. There is also a set of I/O peripherals.
The software contains a certified KNX-RF stack, an RF adaptation layer, and S2-LP library needed to connect the transceiver to create a low power wireless KNX node. The S2-LP operates in the 868.3MHz band at only 10mA with +10dBm output, reports ST, for what it claims is market-leading, energy efficient, secure and robust wireless connectivity which can prolong battery run-time and reducing the overall cost of the end product.
ST explains that combining the S2-LP radio and BlueNRG-2 SoC allows a smartphone to access KNX-based networks and provide an intuitive interface to monitor, control, configure, provision and update the KNX nodes.
Whether hosted on the BlueNRG-2 or STM32 MCU, ST’s KNX-RF software enables power savings for pushbuttons, light switches, occupancy sensors, roller-shutter controls, dimmer actuators, and other devices for lighting, heating, HVAC, and energy-harvesting systems, confirms ST.
The software meets the latest KNX-RF Multi specification, which supports secure (S mode), encrypted communications and frequency agility. Five channels help to avoid interference and permit fast and slow communication modes to save power. The KNX-RF Multi is also claimed to boost reliability and allow larger numbers of KNX devices to co-exist on the network, including listen before talk (LBT), fast acknowledge with auto-retry, and support for repeaters.
ST has teamed with authorised partner, Tapko, which provides the certified KNX stack and Actimage for the RF adaptation layer.
ST also offers the STKNX integrated transceiver for KNX TP communication over twisted-pair cable. The portfolio of products for smart building communications covers all major industry standards, says ST and enables wired and wireless KNX specifications. ST also provides embedded software, evaluation tools, and mobile apps to accelerate the development of Bluetooth Low Energy Mesh and 6LoWPAN networking solutions for smart-building and industrial applications.
Both S2-LP and BlueNRG-2 devices belong to the ST 10-year longevity programme.