WeatherLink Live

Davis WeatherLink Live

The Davis WeatherLink Live device is fully supported by Cumulus MX.

Cumulus MX also supports historic data catch-up by using the Davis WeatherLink.com cloud data source - though this does require you to have a Pro licence to enable the feature.

There are a few caveats around this though...

• You must have at least a Pro subscription for your device on WL.com to grant access to the historic data.
• The new APIv2 used to access the data is still in testing and development by Davis. Though it seems pretty stable, and I have discovered no bugs in the calls Cumulus uses.
• The APIv2 keys are not yet available via WL.com, you must request them on the developer forum - see below for details.

If you meet the criteria and are willing to accept that the API is not yet "production" ready, then these are the steps you need to follow...

1. Sign on to the Davis APIv2 developer forum: https://gitter.im/WeatherLink/v2-api
2. Post a message copying @jeremywall-davis, and request an API key. Jeremy should reply privately within a day or two giving you your API key and secret.
3. Ensure you are running Cumulus MX v3.4.0 or later
4. If this your first run of CumulusMX.
   1. Add a local firewall rule on your server to enable UDP port 22222 inbound
   2. Go into the Station setup and select Davis WLL as the station type
   3. In the WLL section enter your API key and secret. LEAVE THE STATION ID BLANK
   4. Set up your sensor to transmitter ID mappings if different from the defaults
   5. It is not necessary to enter the WLL IP address, Cumulus should just find it on your network. But if you know it it does not harm to enter it, Cumulus will change it anyway if your WLL ever changes address.
   6. Save the setup
   7. Stop/Restart Cumulus
5. If you only have a single station registered with WL.com, then Cumulus should discover its ID automatically and start using it
6. But if you have more than one, the Cumulus will list their API IDs and names in the console window.
7. Note the ID you want to use. Go back into the Station setup and enter the ID there. You do not need to restart Cumulus after that.
8. Enjoy! Cumulus should now download missing data for periods it is stopped.

Eventually once the APIv2 is out of testing, then you should be able to retrieve your APIv2 key and secret via the normal WL.com page along with the existing APIv1 (until it is retired).

There is effectively no limit on how much historic data you can download++, I have tested using a four day catch-up without issues.

Once APIv2 goes live Davis will impose rate and data limits - currently they are proposing...

• 300 API calls per hour, or 2 API calls per second
• 24 hours of data in any one call

Cumulus honours these restrictions.

The APIv2 uses both a key and a secret that encrypts part of the URL making playback or emulating the API calls by another user impossible. A nice feature other web APIs could emulate.

++Cumulus MX will get the max 24 hours data per call if required, which will give a limit of 300 days of historic data catch-up.