Krzysztof Strehlau's Custom Zigbee Gateway Houses an Espressif ESP32-S3 and SiLabs' EFR32MG1
Design delivers "full control over devices, control over the flow between Zigbee and the internet, and voice notifications," the maker says.
Software developer and maker Krzysztof Strehlau has created his own Zigbee gateway, building around an Espresiff ESP32-S3 and a Silicon Labs EFR32MG1 system-on-chip to deliver a custom, compact, personalized device for home automation.
"But why just [not] buy a Zigbee USB stick," Strehlau asks, rhetorically, of the impetus behind his project. "I would like to have full control over devices, control over the flow between Zigbee and the internet, and voice notifications in one device. In my old apartment I had basic power outlet setup controlled via a 433MHz radio controlled by [An Espressif] ESP8266. However, as we're reaching another life milestones with my amazing wife, some inspiration [has] grown in my head and I've challenged myself to build my own Zigbee gateway."
Strehlau's design uses two modules mounted on a custom-designed PCB: an Espressif ESP32-S3-WROOM-1 and an EBYTE E18, which features a Silicon Labs EFR32MG1 system-on-chip. Between the two, the gadget has Wi-Fi, Bluetooth 5.0 Low Energy (BLE), and Zigbee 3.0 support — with the EBYTE module offloading the work of Zigbee processing from the ESP32 host processor. To deliver audio notification,s the board also features an Analog Devices MAX98357A digital to analog converter (DAC) and 3W amplifier — while there's an on-board temperature sensor for good measure.
"The most challenging part was soldering the DAC chip," Strehlau explains, "and then a bit easier was USB [Type-C] soldering. Recently I have been mainly involved in firmware development," the maker continues, detailing improvements including a power-saving clock-speed adjustment that down-shifts the ESP32-S3 from 240MHz to 80MHz when not playing audio, automatic baud-rate detection, over-the-air updates, audio playlist support, and, most recently, a 3D-printed housing — though this will need to be revisited, as a design mistake placed the mounting points on the outside of the case.
The project, which is still a work-in-progress, has been written up on Hackaday.io.