STMicroelectronics ST-KNX Home and Building Automation Chipset

The Internet of Things, sensors and artificial intelligence make buildings increasingly smart, and the convergence of these technologies brings new opportunities for people to simplify their daily lives. With the growing demand for convenience, flexibility and user-friendliness, wired or wireless sensor/actuator networks are becoming increasingly important. In addition, building control automation can also improve the energy efficiency and IT security of buildings.

KNX has been the global standard for building communication and automation for many years. The standard dates back to 1990 with the EIB (European Installation Bus).

After merging with standards such as BATIBUS (France) and the European Home Systems Association (Netherlands), the KNX Association was founded in 2006. Through the KNX distributed bus system, KNX-certified products from different manufacturers can be interconnected.

Figure 2)

All KNX networks use one Engineering Software Tool (ETS) for configuration and diagnostics of devices.

The most commonly used physical layer media for data transmission are twisted pair, network cable (IP protocol) and 868MHz radio frequency carrier.

ST's existing KNX-certified chipsets support all transmission media and have the potential to be further extended to mobile devices such as Bluetooth5-compatible smartphones or tablets.

Figure 3)

STKNX is a twisted pair KNX transceiver with 2 integrated voltage regulators to power KNX bus devices, protecting the largest market share of KNX wired communication in today's building automation field.

The KNX-RF transceiver currently uses a communication frequency of 868 MHz.

With the help of ETS software, KNX devices can be easily integrated into the KNX wired infrastructure.

The chipset is open to the KNX-RF protocol stack software from KNX certified partners.

TAPKO Technologies www.tapko.de already provides a KNX-certified KNX protocol stack (KAIStack) for STMicroelectronics platforms.

Figure 4 shows the KNX-RF and BLE protocol stacks integrated in the software layer of the BlueNRG-2 master controller, which is connected to the SubGHz KNX-RF transceiver via the SPI interface.

Therefore, the 32-bit Cortex M0 ARM-based BlueNRG system chip is the S2-LP controller and also the controller for BLE Bluetooth communication with iOS or Android mobile devices.

Figure 4) Figure 5)

Figure 5) shows a building automation development environment developed by STMicroelectronics that includes KNX and BLE evaluation boards. If Bluetooth is required, the development environment also provides BLE certified modules (BlueNRG-M0/M2) developed by STMicroelectronics.

If the BLE functionality is not required, the STM32 microcontroller can also be used as a master controller for KNX-RF.

All components and the KNX protocol stack are KNX certified and can be found at the following URL:

in conclusion:

The market for KNX certified products has been growing in the field of building automation applications. Room management, lighting control, home building security monitoring, and remote automatic control systems for blinds, curtains, heating, ventilation and air conditioning can provide intelligent solutions for smart buildings.

ST's wide range of MEMS and image sensors monitor motion, environment or light in building networks.

Adding Bluetooth Low Energy to the KNX infrastructure makes device configuration easier and enables the use of mobile devices as a human-machine interface to control KNX devices.

Using KNX in buildings also helps to reduce energy consumption, as radio frequency communication allows existing infrastructure to be modernized without having to lay new cables.

Furthermore, with regard to the current hot topic of connecting electronic gas meters, water meters, electricity meters and heating cost allocators to smart grid solutions, communication interfaces could be developed to enable these meters to communicate with the subGHz wireless connectivity standards used by modern metering systems, e.g. Wireless M-BUS / OMS etc.

About the author:

Michael Muenkel graduated in Communications Engineering from the University of Applied Sciences in Esslingen. Since 1987, he has worked in development, application consulting and marketing for various companies. He joined STMicroelectronics in 1999 and is currently the Marketing Manager for RF and Sensor Technologies. michael.muenkel@st.com