ST introduces new battery-saving wireless MCUs optimised for remote controls
STMicroelectronics has introduced the STM32WL3R, a wireless microcontroller (MCU) optimised for remote control units in consumer products and home automation. Evolved from the STM32WL3 sub-GHz wireless MCU, the STM32WL3R contains a low-power RF transceiver, flexible power-saving states, and six individual wake-up pins that facilitate creating energy-efficient remotes.
ST co-developed the STM32WL3R with France-based building-automation innovator Somfy group, which produces smart systems including wirelessly controlled electric roller shutters, garage openers and connected solutions for home and commercial applications. Engineers at Somfy labs worked with ST to design the new MCU for their next-generation RF remotes and sensors, resulting in a compact and cost-efficient unit that offers flexibility and extended battery life for a great user experience. “This single-chip wireless MCU, optimised for use in remote-control units, lets us continue setting the pace in systems for smarter, more comfortable, and environmentally friendly buildings,” said Serge Robin, RF Development Manager at Somfy.
With its specially engineered RF transceiver, the STM32WL3R is the world’s first Cortex-M0+ multiband wireless MCU to operate in the 315MHz band allocated for remote controls in North America, while the support of the 850MHz and 950MHz ISM bands qualifies its use in products approved for sale worldwide.
Specially adapted for the STM32WL3R, the MCU’s extra power-saving states give greater control to deactivate unused circuitry while also optimising the system wake-up time. In these states, battery life is extended while RAM retention preserves the application context to ensure fast wake-up and thus provide the best possible user experience. Among the states available, ultra-deep stop draws just 450nA while retaining 16KB of RAM data and there is also an incredibly frugal 14nA shutdown mode with up to six wakeup pins.
By providing six wake-up pins, instead of one, the STM32WL3R allows richly featured remotes while simplifying circuit layout and facilitating reuse of the PCB design in multiple product variants.
