Cloud-compatible Wi-Fi module eases IoT and M2M applications

March 07, 2017 //By Julien Happich
STMicroelectronics' SPWF04 Wi-Fi module integrates an ARM Cortex-M4 STM32 microcontroller with a rich set of multi-functional GPIOs and with 2MB on-chip Flash and 256Kbyte RAM for generous code and data storage.

Further extra features include a hardware cryptographic accelerator and an SPI port for faster host communications. In addition, a new MicroPython scripting engine dramatically simplifies development of custom applications to run directly on the module in standalone mode. Host interactions can use AT commands via a UART, compatible with the previous generation of Wi-Fi modules, or equivalent proprietary protocol over SPI.

Support for strong internet-security protocols includes WPA2-Enterprise, which enables enhanced authentication and access control in large networks, and Wireless Protected Setup (WPS) that helps safely connect devices like printers or embedded systems. There is also support for advanced HTTPS and encryption protocols including Transport Layer Security (TLS), as well as Secured Over-The-Air (OTA) updates for applying software, firmware, or Flash file-system upgrades in the field via the Wi-Fi connection.

A full-featured TCP/IP protocol stack including HTTP, HTTPS, MQTT, SMTP, and WebSockets, simplifies connections to the Cloud and mobile devices such as smartphones or tablets.

Versatile operating modes simplify integration with existing network infrastructure, using the module in Station mode, or setting up direct point-to-point connections using the module in MiniAP mode as an access point for other devices (up to five stations). The 26.92x15.24x2.35mm module draws as little as 40µA in standby and 5mA in idle connected (DTIM=1) mode. Two versions are available, with a highly efficient ISM-band antenna (SPWF04SA), or with a built-in U.FL connector for attaching an external antenna (SPWF04SC).

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