Open source · Zigbee · Battery powered
Feel the wind.
Before it hurts.
Brezza watches the front bar of your awning and tells your smart home the moment the wind starts shaking it.
How it works
Asleep almost
all the time.
An ESP32-H2, a LIS2DW12 accelerometer and one CR123A cell. When the awning is still, nothing is transmitted.
The LIS2DW12 raises a wake-up interrupt when it detects shaking.
The ESP32-H2 measures vibration for 5 seconds: RMS in mg, gravity removed, independent of orientation.
It joins the Zigbee network, reports the level, and goes back to sleep.
While the shaking continues it wakes every 30 s to measure again. When things calm down, the interrupt is re-armed.
Every 5.5 hours it wakes on a timer just to report the battery level.
In Home Assistant it shows up through ZHA as Vibration RMS (mg), plus battery.
Hardware
Three ways to build it.
Same firmware, same pin map. Pick the one that fits your workshop.
Breadboard
ESP32-H2 SuperMini and a GY-291 breakout, with the cell on the 3V3 pin. The quickest way to try it.
Wiring ›
Module board
Custom 80 × 35 mm PCB with ESP32-H2-MINI-1 and a TPS63900 buck-boost. Assembled by JLCPCB.
KiCad and BOM ›
SuperMini board
The same electronics with a SuperMini soldered by its edge. Easier to source.
KiCad and BOM ›Design decisions and numbers: hardware/SPEC.md
Enclosure
Printed. Bolted. Done.
A box in ASA-GF that sits on the face of the bar, held by two M4 screws into T-nuts in the slot. The Fusion 360 design, the assembly animation and the video are on the v1.0-prototype release.
Firmware
Arduino. Zigbee end device.
The sketch is firmware/brezza/brezza.ino, built with Arduino-ESP32 3.1 or newer.
| Board | ESP32H2 Dev Module |
|---|---|
| USB CDC On Boot | Enabled |
| Partition Scheme | Zigbee 4MB with spiffs |
| Zigbee Mode | Zigbee ED (end device) |
Hold BOOT for 3 seconds at power-up to wipe the stored network. Calibration and bench findings are in the README.
Open by design
Build it. Change it. Share it.
| Firmware | MIT |
|---|---|
| PCBs and enclosure | CERN-OHL-P-2.0 |
| Docs, images, renders, videos | CC BY 4.0 |
The ESP32-H2-MINI-1 footprint, symbol and 3D model come from Espressif (CC BY-SA 4.0). See the README for third-party files.