An awning deployed in the wind is a sail. The arms lever against the fixings, and what breaks is rarely the fabric: it is the wall, the roller tube or the arm itself. And it nearly always happens when nobody is home to retract it.
This setup solves that with a station that measures the real wind on the terrace and a relay that retracts the awning when it passes the threshold.
The four pieces
The Ecowitt WS90 measures, a gateway collects the reading, the Shelly 2PM Gen4 gives the order and the motor retracts the awning.
The piece most often forgotten is the gateway. The WS90 has no Wi-Fi: it transmits over Bluetooth and Zigbee. For its readings to reach the app you need a Shelly BLU Gateway, or any Shelly Plus, Pro, Gen3 or Gen4 device that is not a sensor. If you already have a Shelly near the terrace, it is probably acting as the gateway already.
Mind the range: the WS90’s Bluetooth reaches about 30 metres outdoors, and a load-bearing wall in between eats most of that. The station goes outside on a mast; the gateway, as close as possible.
Your awning gives the threshold
There is no need to invent a number. Standard EN 13561 requires the manufacturer to declare a wind-resistance class, and it is in the awning’s documentation. For folding-arm awnings only two exist:
| Withstands up to | Threshold to set | In the app | |
|---|---|---|---|
| Class 1 | 28 km/h (Beaufort 4) | 18-23 km/h | 5-6.4 m/s |
| Class 2 | 38 km/h (Beaufort 5) | 28-30 km/h | 7.8-8.3 m/s |
Class 1 is the norm for folding-arm awnings without a cassette; class 2, for cassette, drop-arm or vertical awnings. If someone offers you a “class 3” folding-arm awning, something does not add up.
The threshold goes below the limit, not at it: between the sensor detecting the gust, the order travelling and the awning finishing its retraction, several seconds pass, and the wind does not wait. Leave 5 to 10 km/h of margin.
- The app works in m/s. Divide km/h by 3.6.
- Use the gust, not the average. The WS90 reports the gust as the maximum over the last 28 seconds, and gusts are what break things: a 20 km/h average can hide a 45 km/h blow.
The 2PM in cover mode
With cover mode on, the 2PM stops treating its two outputs as separate relays: it interlocks them so they can never be active together and learns the travel with a calibration. From then on you ask it to “retract” or “go to 40 %”, not “turn for two seconds”. Without calibration, the retraction sometimes stops halfway.
Cover mode drives two-direction 230 V AC motors. It does not work with DC motors. Check the motor’s rating plate before buying anything: this is the mix-up behind most returns.
With a DIN-rail panel or several awnings, the Shelly Pro Dual Cover PM does the same with two motors. The Shelly 2PM Gen3 has the same cover mode, without Zigbee or Matter.
Step by step
- Fit the 2PM behind the awning switch or in a protected box, with the motor’s two control wires on O1 and O2.
- In the app, enable cover mode and run the full calibration.
- Mount the WS90 on a Ø25 mm mast, in the open, with the north marker aligned. Against the wall, on the lee side, it measures anything but the wind.
- Add the WS90 to the app through the gateway.
- Create the scene: if the gust exceeds X m/s, retract the awning.
- If the awning lacks the pitch to shed water, add a rain scene too: pooling breaks arms just as wind does.
- Test it with an absurd threshold — 2 m/s — and check that it really retracts. Then set the real one.
And add a lock condition so that no other scene — the sun one, say — deploys it while the wind is still up.
What can fail
A wireless automation is not a wired wind sensor. It has three points of failure that a wired sensor does not:
- Batteries. The WS90 runs on a solar panel backed by two lithium AA cells, which last about six months. After a grey winter with flat cells, it stops reporting. Heed the low-battery warning.
- Range. Move the gateway or the router and you can lose the link without knowing until the windy day.
- The cloud. If the scene runs in Shelly’s cloud and the internet goes down, the order never leaves. And with no power there is neither motor nor relay.
So for a large or expensive awning, or a very exposed wall, the manufacturer’s wired wind sensor is still the primary protection: it acts when everything else is down. The WS90 adds rain, solar radiation, barometric trend, alerts and history. For a small terrace awning, the WS90 alone is enough for most people.
Frequently asked questions
Does it work with Home Assistant?
Yes, but not the way people expect. The BLU Gateway sends the data to Shelly’s cloud and does not expose it on the local API. What works is picking up its BTHome broadcasts with a Bluetooth adaptor or a BLE proxy, or integrating it directly over Zigbee.
What batteries does it take?
Two 1.5 V lithium AA cells, not included. With the internal heater on, alkalines can overheat and leak in cold or damp, and it does not accept NiMH or NiCd rechargeables.
How accurate is its wind measurement?
±1 m/s below 10 m/s and ±10 % above. Plenty for deciding whether to retract an awning; allow for it when setting the margin.
Does it work for roller shutters too?
Yes, with the same setup. Wind matters less for shutters, but the same station can lower them on solar radiation in summer.
Switch off and verify there is no voltage before touching the motor; the 230 V connection is a job for a qualified installer. And respect the awning manufacturer’s wind, rain and temperature limits: the automation does not replace the standard, it applies it.