Radio modules using STMicroelectronics’ STM32WB55 wireless microcontroller are available from Arrow Electronics. The Sharky modules were co-developed with Italian designer, Midatronics. By Caroline Hayes
The microcontroller integrates a 2.4GHz RF transceiver supporting Bluetooth 5 (including Bluetooth Low Energy), Thread, and ZigBee stacks. Its dual Arm Cortex-M core architecture enables real-time secure application performance running on the 64MHz Cortex-M4F core, and concurrently manages the radio subsystem and security tasks on the integrated but independent Cortex-M0+
The MDX-STWBP-01 and MDX-STWUP-R01 Shrarkypro modules have an on-board PCB antenna or a UFL connector, respectively, for attaching an external antenna. Balun circuitry for connecting the antenna is integrated in the microcontroller. There is also the MDX-STWBC-R01 and MDX-STWBW-R01 modules, with a choice of a chip antenna or no antenna, respectively.
The power-efficient modules draw 13nA in shutdown mode and 600nA in standby with the microcontroller real-time clock and RAM powered up. Receive sensitivity is -96dBm and RF output is programmable, with low active current at 4.5mA receive and transmitting at 0dBm.
For security, the microcontroller’s hardware-based encryption consists of public key authorisation (PKA) and random number generator (RNG), with customer key storage to keep keys hidden.
The modules are supplied with the RF (32MHz) and 32.7kHz crystals required by the microcontroller, already fitted. Developers can use ST’s STM32Cube development ecosystem, with configuration tools, middleware, and new extensions for the microcontroller, including peripheral drivers, connectivity libraries, and a monitoring tool for RF testing.