Zigbee networking is a key element in home automation, smart lighting, smart building, and broad Internet of Things (IoT) connectivity. So STMicroelectronics’ addition of Zigbee 3.0 support to its STM32WB55 wireless microcontrollers is welcome news to designers of these sorts of systems. Zigbee 3.0 unifies the features of Zigbee specifications for consumer and industrial applications, a move that has driven major consumer and Internet brands to choose Zigbee connectivity for new smart-home products.
ST’s Zigbee 3.0 software for STM32WB55 includes the Exegin Zigbee PRO protocol stack, provided free of charge, and delivered and fully supported by ST. This stack is used in Exegin products certified as Zigbee Golden Units and is approved as a reference stack for use by test laboratories. To further ease development, ST’s offer supports 46 Zigbee 3.0 clusters that help users quickly establish device capabilities. A further 21 clusters support legacy products.
STM32WB55 microcontrollers also support Thread and Bluetooth 5.0, with over-the-air update (OTA) capability. There are currently 10 STM32WB55 variants, offering a choice of package styles and flash-memory density from 256 Kb to 1 Mb. Further variants scheduled to be introduced in the next quarter will give developers extra flexibility to meet application performance and cost targets. The devices feature the Arm Cortex-M4 with floating-point unit, DSP instructions, and a memory protection unit (MPU) that enhances application security. An Arm Cortex-M0+ coprocessor dedicated to managing the integrated IEEE 805.15.4 radio and the MCU’s cyber-protection features ensures real-time low-layer operations run smoothly without compromising application execution. The RF transceiver has a link budget of 106 dB, to ensure reliable connections over distance.
ST’s ultra-low-power microcontroller technologies and high feature integration, which include the radio balun circuitry, ensure STM32WB55 devices help designers meet tight power and size constraints in a wide range of IoT and wearable devices. There are rich analog and system peripherals, as well as cyber-protection and ID features including secure firmware installation (SFI), customer key storage, hardware public key authority (PKA), and cryptographic accelerators. Capacitive touch and LCD controllers also simplify user-interface integration.
The Zigbee 3.0 software is now included in the STM32CubeWB MCU package, which provides embedded software including low-layer (LL) APIs and hardware-abstraction layer (HAL) drivers for STM32WB microcontrollers, as well as Bluetooth 5.0, Mesh V1.0, and Thread libraries, FreeRTOS kernel, FatFS file system, and the STMTouch capacitive-sensing library. The STM32Cube ecosystem, through STM32CubeMonitor-RF for RF testing and STM32CubeMX for device configuration and code generation, ensures more comfortable and easy development.