STMicroelectronics Cloud compatible Wi-Fi modules simplify and secure IoT and M2M applications

     STMicroelectronics' latest cloud-compatible Wi-Fi module will accelerate the development of various iot hardware and machine-to-machine communication devices. The new module provides advanced network security features and application protocols, and the built-in microcontroller supports stand-alone or serial port to Wi-Fi mode.

     The SPWF04 Wi-Fi module integrates an ARM® Cortex-M4 STM32 microcontroller with a variety of feature-rich GPIO ports, 2MB on-chip flash memory and 256KB RAM to provide ample storage space for code and data. Other features include a hardware cryptographic algorithm accelerator and an SPI port for connecting hosts with faster communication speeds. In addition, the new MicroPython scripting engine greatly simplifies the development of custom applications that run directly in modular stand-alone mode. The module interacts with the host device, either through the UART transceiver using AT commands compatible with previous generation Wi-Fi modules, or through the SPI port using an equivalent communication protocol unique to the customer.

     The new module supports robust network security protocols, such as WPA2-Enterprise for stronger authentication and access control security on large networks, and Wireless Protection Settings (WPS) to help secure printer or embedded device connections. The new module also supports advanced HTTPS and encryption protocols, including Transport Layer security (TLS) and software secure over-the-air download (OTA) updates over Wi-Fi wireless field updates of software, firmware or flash file systems.

     The full-featured TCP/IP stack, which includes HTTP, HTTPS, MQTT, SMTP, and WebSockets, helps simplify module connectivity to the cloud and mobile devices, such as smartphones or tablets. Several UDP[1] protocols, including TFTP, SNTP, and mDNS, aid device search and file exchange. Other product highlights include IPv6 support, web Server Extensions (SSI) that simplify the interaction of networked devices, and REST(Representational State Transition) apis that efficiently use bandwidth to effectively interact with web resources.

     The flexible mode of operation simplifies the module's integration with the existing network infrastructure, with the module's Station wireless site mode for connecting wireless routers and the MiniAP mode for establishing direct point-to-point connections to provide access points for other devices (up to five wireless sites). SPWF04 also has an extended socket protocol layer that can manage up to eight socket clients or two socket servers, and each module can handle up to eight clients or two WebSocket clients simultaneously.

     Like the previous generation, the SPWF04's RF output power and reception sensitivity are high, ensuring communication reliability even in harsh communication environments. In addition, the new module offers increased performance and functionality within strict size and power limits, with a module size of only 26.92mm x 15.24mm x 2.35mm, and power consumption in standby mode and connected idle mode (DTIM=1) of 40µA and 5mA respectively.

     At present, there are two SPWF04 products, one is a built-in high energy efficiency ISM band antenna (SPWF04SA), and the other is equipped with a U.FAST antenna interface (SPWF04SC), which requires a separate external antenna. The new modules are FCC(US), CE(EU) and IC(Canada) certified products and comply with European RoHS regulations, thus simplifying the final product to obtain the relevant mandatory certification.