KNX IoT

Thread-based connectivity for KNX building automation

Overview

KNX is a widely deployed building automation standard, traditionally run over a wired twisted-pair bus. KNX IoT is a new physical layer for KNX: The KNX Association's open-source KNX IoT Point API enables KNX devices to communicate wirelessly over IPv6 networks rather than the existing wired bus. Nordic supports KNX IoT over Thread, a low-power, IPv6-based wireless mesh protocol, bringing wireless connectivity to KNX sensors and actuators for the first time without requiring new wiring.


Why Thread

for KNX-IoT

KNX had very limited existing wireless options. KNX RF is confined to Europe and doesn't support IP or mesh topology. KNXnet/IP, the existing IP-based option, isn't low-power. It works well as network backbone infrastructure, but not as a transport for battery-powered sensors and actuators.

Thread is a global, low-power, IPv6-based mesh protocol running in the 2.4 GHz ISM band, so KNX IoT devices over Thread can run on batteries for years instead of months, and can be deployed anywhere in the world, not just Europe. It also removes the need to run wiring to every device: retrofitting a KNX IoT sensor over Thread instead of twisted-pair wiring can cut installation cost by roughly 10x, which matters a lot in retrofit-heavy markets like commercial and residential building automation.


Nordic's Involvement

Nordic joined the KNX Association to support the development of KNX IoT over Thread. This builds on our existing Thread leadership: We were the first semiconductor company to provide production support for the OpenThread stack, and that same multiprotocol foundation now extends to KNX IoT.

KNX IoT add-on for nRF Connect SDK

Nordic maintains a KNX IoT add-on for the nRF Connect SDK, integrating the KNX Association's official KNX IoT Point API Stack. The current release, v0.1.0, is a first experimental release:

  • Integrates KNX IoT Point API Stack v1.0.0, the official stack released by the KNX Association in March 2026.
  • Runs over Thread on the nRF54LM20A, nRF54LM20B, and nRF54L15 SoCs.
  • Compatible with nRF Connect SDK v3.4.0, the long-term stable (LTS) release.
  • Ships with Light Switch Sensor and Light Switch Actuator samples.
  • Commissioning is currently hardcoded for lab evaluation, not yet suitable for production deployments.

Docs: https://nrfconnectdocs.nordicsemi.com/addons/ncs-knx-iot/0.1.0/index.html

Compatible SoCs

nRF54L15 SoC

Ultra-low-power wireless SoC for Bluetooth LE, Bluetooth Channel Sounding, Matter, Thread, Zigbee, Aliro, and Amazon Sidewalk

128 MHz Arm Cortex-M33
1.5 MB NVM, 256 KB RAM
Extended peripheral set
RISC-V Coprocessor
Advanced security
CSP package option

Read more

nRF54LM20A SoC

Ultra-low-power wireless SoC for Bluetooth LE, Bluetooth Channel Sounding, Matter, Thread, Zigbee, and Aliro

128 MHz Arm Cortex-M33
2 MB NVM, 512 KB RAM
Extended peripheral set
RISC-V Coprocessor
High-speed USB
Advanced security
Up to 66 GPIOs
CSP package options

Read more

nRF54LM20B SoC

Ultra-low-power wireless SoC with integrated Axon NPU, for hardware-accelerated edge AI applications, supporting Bluetooth LE, Channel Sounding, Bluetooth Mesh, Zigbee, Thread, Matter, Aliro, and 2.4 GHz proprietary protocols.

128 MHz Arm Cortex-M33
2 MB NVM, 512 KB RAM
128 MHz integrated Axon NPU
High-speed USB

Read more