Espressif has officially launched a software stack and hardware development kit which turns its ESP32 range of microcontrollers into Thread Border Routers for Matter smart home networks — complete with official certification from the Thread Group.
"We are glad to announce that the Espressif Thread Border Router (ESP Thread BR) solution has received certification from the Thread Group," Espressif's Shu Chen said of the launch, "and the accompanying development kit has now been officially released. [The] ESP Thread BR solution is based on the combination of Espressif’s Wi-Fi and 802.15.4 SoCs [Systems on Chips], built on the ESP-IDF and open-source OpenThread stack."
The Thread Border Router is designed, as the name implies, to serve as a router at the border between low-power IEEE 802.15.4-based Thread and high-performance IEEE 802.11-based Wi-Fi networks. Previously, one of the most popular approaches for building a Thread Border Router is to use the OpenThread stack atop a POSIX-compliant operating system like Linux — requiring a device with enough memory and processing power.
Espressif's approach, though, builds atop the company's own ESP-IDF framework and uses embedded-friendly integrated components to drop the requirements low enough to perform perfectly well on the company's ESP32, ESP32-C, and ESP32-S families of 32-bit microcontrollers working in partnership with the ESP32-H. "In [our] solution, the Host Wi-Fi SoC operates the Espressif Thread BR and OpenThread Core stack," Chen explains, "while the [ESP32-H] 802.15.4 SoC runs the OpenThread RCP (Radio Co-Processor). Communication between the two is established through the Spinel protocol."
As released, the ESP Thread Border Router stack includes support for bi-directional IPv6 connectivity with Wi-Fi and Ethernet backbones, bi-directional service discovery, multicast forwarding, NAT64 to allow Thread devices to access the IPv4 internet, an over-the-air (OTA) update system which combines the firmware for both microcontrollers into a single download, radio-frequency coexistence, and what the company calls a "user-friendly" browser-based graphical interface.
The ESP Thread Border Router software development kit is now available on GitHub under the permissive Apache 2.0 license, with documentation on Espressif's website; a companion development board, which combines an Espressif ESP32-S3-WROOM-1 module and ESP32-K2 with an ESP32-H2 submodule, can be purchased from the Espressif AliExpress store for $18 plus shipping.