Configuration

All configuration lives in the [LoopData] section of weewx.conf, which the installer creates. This page documents every option; the sample configuration at the bottom is exactly what a fresh install writes.

[[FileSpec]]

Option Meaning
loop_data_dir The directory into which the loop data file should be written. If a relative path is specified, it is relative to the target_report directory.
filename The name of the loop data file to write (loop-data.txt by default).

The file is written atomically (a temp file in the same directory, then a rename), so a reader can never see a partial write.

[[Formatting]]

Option Meaning
target_report The WeeWX report to target. LoopData uses this report to determine the units to use and the formatting to apply. Also, if loop_data_dir is a relative path, it is relative to the directory of target_report. When LoopData is first installed, target_report is set to the sample report included with the extension: LoopDataReport (also the default if the option is absent).

Why does LoopData need a report at all? Because conversions are decided by the report, not by the units stored in the database: if the database is metric but the target report specifies US units, day.outTemp.avg arrives as 68.2°F. On every loop packet, LoopData applies the target report’s converters and formatters, so each value lands in loop-data.txt exactly as the WeeWX reporting cycle would have rendered it — page javascript can drop values straight into HTML. Individual fields can override the unit or formatting; see the field reference.

The target report also supplies the language: the trend.barometer.desc descriptions, moon phases, compass ordinates, almanac body and constellation names, and hemisphere letters all follow the target report’s lang file — see Translations.

[[LoopFrequency]]

Option Meaning
seconds The frequency of loop packets emitted by your device. This is needed to give the proper weight to accumulator entries. For example, this value is 2.0 for Davis Vantage Pro 2 and RainWise CC3000 devices.

It is crucial to specify the correct loop frequency. For vantage and cc3000, this will be 2 seconds.

[[RsyncSpec]]

Only needed if you push loop-data.txt to a remote webserver — see Syncing to a remote server for the how and why.

Option Meaning
enable Set to true to rsync the loop data file to remote_server.
remote_server The server to which the loop data file will be copied. Passwordless ssh using public/private key must be configured from the user account weewx runs under to the account on the remote machine with write access to remote_dir.
remote_user The userid on remote_server with write permission to remote_dir.
remote_dir The directory on remote_server where filename will be copied.
compress True to compress the file before sending. Default is False.
log_success True to write success-with-timing messages to the log (for debugging). Default is False.
ssh_options Extra options for the ssh transport (e.g., a key file or port). Whether or not this is set, LoopData appends safety bounds for any keyword you don’t set yourself: -o ConnectTimeout=<timeout>, -o ServerAliveInterval=<timeout>, -o ServerAliveCountMax=2 and -o BatchMode=yes, so a dead or hanging remote cannot stall the loop processing thread (an option you set always wins).
timeout I/O timeout. Default is 1 (when sending, time out in 1 second). Also used for the ssh ConnectTimeout and ServerAliveInterval bounds described under ssh_options. 0 disables all time bounds.
skip_if_older_than Don’t bother to rsync if the data is older than this number of seconds. Default is 3. (Skip it and move on to the next packet rather than shipping stale data late.)

[[Include]]

Option Meaning
fields The fields to include in the json file — a bare comma-separated list. Each entry is a report tag with the $ removed; each becomes a key in loop-data.txt. The complete grammar is in the field reference.

The json file will only include the fields specified here (plus the automatic windrose.bands key when any windrose field is configured).

A field entry containing a comma — a formatting call with two arguments, or an almanac tag with two keywords — must be quoted, or ConfigObj will split the entry at the comma into two bogus fields: fields = ..., 'day.rain.sum.format("%.2f", add_label=False)', ...

Translating trend.barometer.desc

As of 6.4 the descriptions served for trend.barometer.desc (Falling Slowly, Steady, …) are gettext-style keys into the target report’s [Texts] — translate them in the target report’s lang file (the sample report’s shipped lang/de.conf, lang/fr.conf, lang/nl.conf and lang/es.conf already carry all nine), or override a description without touching any skin file:

[StdReport]
    [[LoopDataReport]]
        [[[Texts]]]
            "Steady" = "Holding steady"

The pre-6.4 [LoopData] [[BarometerTrendDescriptions]] section is gone and now ignored — delete it from weewx.conf.

trend.barometer.code (an integer from -4 through 4) is the language-neutral companion; see Special fields.

windrose_bands

Overrides the wind-speed band edges used by the windrose observation. Ascending edges, in the target report’s windSpeed unit; the first edge doubles as the calm threshold:

[LoopData]
    windrose_bands = 1, 4, 8, 13, 19, 25

The default is the classic WRPLOT/NOAA bands (0.5, 2.1, 3.6, 5.7, 8.8 and 11.1 m/s, converted to the report’s unit). See Choosing your bands for how to pick edges suited to your site.

The trend window (time_delta)

The trend window cannot be changed on a case-by-case basis, but it can be changed for the entire target report, using the standard WeeWX customization — in the target report’s configuration:

    [[[Units]]]
        [[[[Trend]]]]
            time_delta = 86400    # for a 24 hour trend.

The default is 10800 (3 hours) — a WeeWX default. If time_delta is greater than 259200 (3 days), LoopData caps it at 259200.

Sample configuration

Fresh installs add the following [LoopData] section to weewx.conf. The fields line is exactly the fields the sample report’s instrument panel reads. Upgrading installs keep whatever fields line is already in weewx.conf — to adopt the panel, replace your fields line with this one (appending any fields other pages of yours use).

[LoopData]
    [[FileSpec]]
        loop_data_dir = .
        filename = loop-data.txt
    [[Formatting]]
        target_report = LoopDataReport
    [[LoopFrequency]]
        seconds = 2.0
    [[RsyncSpec]]
        enable = false
        remote_server = foo.bar.com
        remote_user = root
        remote_dir = /var/www/html
        compress = False
        log_success = False
        timeout = 1
        skip_if_older_than = 3
    [[Include]]
        fields = current.dateTime.raw, current.outTemp, current.outTemp.raw, day.outTemp.min.raw, day.outTemp.max.raw, day.outTemp.min.formatted, day.outTemp.max.formatted, current.outHumidity, current.outHumidity.raw, day.outHumidity.min.raw, day.outHumidity.max.raw, current.windSpeed, current.windSpeed.raw, current.windDir.raw, current.windDir.ordinal_compass, 10m.windGust.max, 10m.wind.gustdir.raw, 10m.wind.gustdir.ordinal_compass, current.barometer, current.barometer.raw, trend.barometer.raw, trend.barometer.desc, current.rainRate, current.rainRate.raw, day.rain.sum, day.rain.sum.raw, day.rainRate.max, day.rainRate.max.raw, current.dewpoint, current.dewpoint.raw, day.dewpoint.min.raw, day.dewpoint.max.raw, day.dewpoint.min.formatted, day.dewpoint.max.formatted, current.appTemp, current.appTemp.raw, day.appTemp.min.raw, day.appTemp.max.raw, day.appTemp.min.formatted, day.appTemp.max.formatted, current.UV, current.UV.raw, day.UV.max, current.radiation, current.radiation.raw, day.radiation.max, current.pm2_5, current.pm2_5_aqi.raw, current.pm2_5_aqi.formatted, day.windrose.banded, day.windrose.calm, unit.label.outTemp, unit.label.barometer, unit.label.rain, unit.label.rainRate, unit.label.windSpeed

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