This guide walks you through buying and installing the kit that Elf reads its vineyard data from:
- Ecowitt weather station - temperature, humidity, wind, rainfall
- Ground-level temperature sensor - the part that matters most for frost protection
- OpenSprinkler controller - switching spray sections on from your phone
It is the same kit we run at our own Pustkowie Vineyard. In spring 2025, with the temperature falling to -1.9°C, we did not lose any buds.
What Elf does not do
Start here, because it shapes the buying decision: Elf observes and recommends, a person switches the hardware on. The screen shows you the ground temperature, the trend through the night, the risk level and a recommendation of which spray sections to run - but it will not send the command for you. You confirm the start in the app.
Elf does not send notifications either: no SMS, no email, no WhatsApp messages. Warnings are visible once you open the module screen. If the forecast points to a frost night, you still set your own alarm clock.
The hardware gives you an accurate reading from your own block and remote control from your phone, instead of walking out to the pump at 3 a.m. It does not give you an automation that runs while you sleep.
Part 1: Ecowitt weather station
The station gives Elf a measurement from your own block instead of model data for the nearest grid point. The critical part is not the anemometer but the ground-level temperature sensor - that reading drives the frost risk, because near the soil it can be 2-3 degrees colder than at screen height.
What to buy
A basic kit is enough to start:
- Ecowitt GW1100 or GW2000 gateway - receives the sensor data and sends it to the cloud, around EUR 35-60
- WH32 or WH31 temperature and humidity sensor - often bundled with the gateway, around EUR 20 on its own
Worth adding:
- WN34 - ground-level temperature sensor, around EUR 15. For frost protection this is essential, not an extra.
- WS69 or WH65 - full station with wind, rain and UV, around EUR 100-140
Where to buy: Amazon and local marketplaces, home-automation retailers, or directly from ecowitt.com (longer shipping).
Mounting
The gateway sits indoors, within WiFi range and where the radio signal from the sensors reaches it. USB power is fine.
The outdoor sensor goes on a post or a wall on the shaded side, away from direct sun. Mount it 1.5-2 m above ground, away from buildings and concrete - they store heat and push the night reading up.
The WN34 ground sensor goes 10-20 cm above the soil, in the middle of the vineyard rather than at its edge. Give it a small shield against direct sun. This is the reading that counts on a frost night.
Setting up the gateway
- Install the Ecowitt app from the App Store or Google Play and create an account.
- Add the device: reset the gateway by holding its button, connect your phone to its WiFi network (the name starts with ECOWITT), then enter your own network details.
- Put the batteries into the sensors. They should appear in the gateway settings on their own - assign channels, for example channel 1 for the post sensor and channel 2 for the ground sensor.
- Check in the app that the readings change. Only then move on.
Make sure the gateway is set to upload to the Ecowitt cloud - it is on by default, but a reset can switch it off.
API keys and the station MAC
Elf reads the data through the Ecowitt API, so it needs three things from your Ecowitt account:
- Sign in at ecowitt.net.
- Open View Devices and check that your data is there. The device entry shows its MAC - a string such as
D8:F1:5B:.... The mobile app shows the same address in the gateway details. - Go to Settings → API Keys.
- Generate an Application Key (the long string) and an API Key (the shorter one).
- Save all three values - you enter them together in Elf.
The MAC tells Elf which gateway to read; the keys alone are not enough, because one Ecowitt account can hold several stations.
Connecting it to Elf
Where: the WineryElf app, Settings, the Sensors section. Only the account administrator can see it.
In the Ecowitt weather station block paste the Application Key, the API Key and the station MAC, then click Save - a Configured label appears next to the block title. While any field is empty, the save button stays disabled.
Then click Test connection: Elf makes a real call to the station and answers with the current air temperature. That is the quickest way to confirm that the keys and the MAC belong together. Readings usually appear on the screens within a few minutes.
When a reading stops refreshing, the frost screen says so directly - it usually means flat batteries in a sensor, or a gateway that has lost WiFi.
Part 2: OpenSprinkler controller
OpenSprinkler is a valve controller that lets you start the sprinklers from your phone. In Elf it also tells the frost protection screen which sections you have, so the screen can recommend which ones to run. You confirm the start yourself.
Buy it only if you already have a sprinkler system. Without valves and pipe there is nothing for the controller to control.
What to buy
The controller, depending on your valves:
- OpenSprinkler 3.0 AC - for standard 24 V AC valves, around USD 170
- OpenSprinkler 3.0 DC - for latching DC valves, around USD 160
Order it from opensprinkler.com, sometimes available on eBay or Amazon.
You also need:
- solenoid valves, one per section (Hunter, Rain Bird and similar)
- two-core cable to each valve
- a 24 V AC power supply, often included
- optionally a rain or flow sensor
Mounting
The controller goes somewhere dry - a distribution box, a garage, a shed. Connect the 24 V AC supply and the network, either by Ethernet cable or over WiFi.
The valves go on the irrigation pipe, one per section. Run a two-core cable from each valve to the controller: one core to the COM (common) terminal, the other to the terminal of its section - 1, 2, 3 and so on.
Before you backfill the trench, run water through each section separately and check that the valve you switch is the one that opens. Mixed-up section numbering is the most common installation mistake and the hardest one to work out at night.
Connecting it to Elf
Elf talks to the controller through OpenThings Cloud - the manufacturer’s cloud service - not through an address on your local network. That way it works when you are away from the vineyard, and it needs no port forwarding on your router.
- In the controller panel (or the OpenSprinkler app) enable OpenThings Cloud and copy the OTC token issued for the device.
- Recall the controller password. The factory default is
opendoor- if it is still in place, change it before you put the controller on the cloud. - Where: the WineryElf app, Settings, the Sensors section. In the OpenSprinkler (OpenThings Cloud) block enter the OTC token and the controller password, then click Save.
- Click Test connection - Elf answers with the number of sections it found in the controller.
Once saved, the password is never shown again; the field then carries a hint that it is stored. Leave it empty if you only want to change the token.
Elf also reads the section names - the ones you set in OpenSprinkler - so it is worth naming them in plain words (“rows 1-6”, “young plantings”) instead of leaving “Station 1”.
Pressure and water
Two things decide whether frost sprinkling works at all:
- Pressure - sprinklers normally need 2-3 bar. Below that the water does not atomise evenly and, instead of protecting the buds, it simply wets them.
- Water supply - a night of sprinkling runs to tens of cubic metres. Work that out before the season, not at 2 a.m. when the tank starts to drop.
Part 3: A frost night in practice
Frost sprinkling works through the latent heat of fusion: as water freezes on a bud it releases heat and holds the bud near zero, even though the air around it is colder. There is one absolute condition - the sprinkling has to run without a break until the ice thaws in the morning. Stopping halfway through the night does more harm than not sprinkling at all.
What Elf shows
Where: the WineryElf app, the Frost protection section.
The screen gives you the ground and air temperature from the Ecowitt station, humidity, wind and gusts, the trend over the past hours, and the risk level. With a controller connected you also see the spray sections and a recommendation of which ones to run.
Reading history builds up only while somebody has the screen open - on a cold night it is worth leaving it open on a phone or tablet, so the trend has readings to calculate the rate of fall from.
The thresholds we work with
These are the settings from Pustkowie Vineyard - not the only sensible ones, but proven in our own block:
- Watch from a ground temperature below 2 degrees with a falling trend
- Start sprinkling at 0.5 degrees and still falling
- Stop only once the temperature is clearly above 3 degrees and the ice has left the buds
- Season from 1 March to 14 June (northern hemisphere; in the southern one it is the spring either side of September)
- Sections run in pairs, because the pressure is not enough for all of them at once
What the seasons taught us
Test the whole system before the season. A poor moment to discover that the valve on section three has not opened since last year is the first frost night. Run each section by hand and watch the sprinklers turn.
Trust the ground sensor, not the forecast. A forecast describes the temperature at two metres. Near the soil, on a still night, it can be 2-3 degrees colder - and that is where the buds are.
A still night under a clear sky is more dangerous than a colder but windy one. Wind mixes the air, so a radiation frost does not settle as low.
Have a plan for a power cut. A controller without power will not open a valve, and frost nights like to arrive with a storm.
Do not count on the app waking you. Elf sends no notifications.
What it costs
| Item | Approximate price |
|---|---|
| Ecowitt GW1100 or GW2000 with an outdoor sensor | EUR 50-70 |
| WN34 ground temperature sensor | EUR 15 |
| OpenSprinkler 3.0 controller | USD 160-170 |
| Solenoid valves, 6 of them | EUR 70-140 |
| Cable and connectors | EUR 25-50 |
| Total | around EUR 330-450 |
Prices are indicative. You can buy the weather station on its own and start there - the sprinkler controller only makes sense once you have a sprinkler system.
Questions
Write to [email protected]. If you get stuck on the mounting or on the keys, tell us what the screen says - we know the common problems from our own installation.