STMicroelectronics and Stackforce – an ST Authorized Partner – have announced a wireless M-Bus (wM-Bus) software stack that leverages the integrated sub-GHz radio and multiple modulation schemes supported by STM32WL microcontrollers to cut bill-of-materials cost and enhance flexibility for developers of smart-metering systems.

Developed by Stackforce, the wM-Bus stack complies with most of EN 13757-3/-7, covering the upper layers of the Wireless M-Bus protocol stack, as well as the lower layers (EN 13757-4) and its wM-Bus modes S, T, and C used throughout Europe in the 868MHz band. The mode N for operation at 169MHz is an option, too. In addition, it meets several other metering standards, including the most common Open Metering System (OMS) specification, as well as more specific standards like Dutch Smart Meter Requirements (DSMR) or CIG Italian Gas Committee specifications.

Supported by the STM32 development ecosystem, STM32WL microcontrollers are ultra-low-power devices that use a range of ST technologies and design approaches to meet smart-meter designers’ needs. The sub-GHz radio inside STM32WL has a wide linear frequency range, dual power output, and can satisfy EN 300 220, FCC CFR 47 Part 15, ARIB T108, and other radio-equipment regulations, including China regulatory requirements to assist development of products for markets worldwide. Other key features include an integrated switched-mode power supply (SMPS) and hardware cryptographic accelerators.

The Stackforce wM-Bus stack is available immediately through here. The wM-Bus over LoRaWAN stack will be available end of July 2020. For more information please visit www.st.com/stm32wl.