How can I get luminosity from WH3080

[sailmich]

Hello I need some help!

I'm running weewx on  RPI3 and with cheetah generator I create "weewx_pws.xml.tmpl" with uv and radiation in it. Now I want to get luminosity for better regulation of my blinds.

I added years ago following code in weewx_pws.xml.tmpl to get additonal value UV and radiation.  

<!--CUSTOMDATA-->
<realtime><data realtime="uv_index">$current.UV.formatted<!--uvIndex--></data></realtime>
<realtime><data realtime="radiation">$current.radiation.formatted<!--radiation--></data></realtime>

So far as I remember I just have to put the code inside the file underneath same as above with UV and radiation

<realtime><data realtime="luminosity">$current.luminosity.formatted<!--luminosity--></data></realtime>

But this dosen't work.

In skin.conf I can't find  luminosity but my PWS shows LIGHT I also tried it with light/LIGHT/LUMINOSITY.

Where can I check wich variable is in use for luminosity or is there another way to get luminosity value or did I miss some other points?

Thank for any help or hint.

Mike 

[gjr80]

Hi,

If your station provides luminosity (and your driver passes it on) just run WeeWX directly (http://weewx.com/docs/usersguide.htm#Running_directly) and you will see what fields are available. Lines starting with LOOP: are loop packets and lines starting with REC: are archive records, you should be able to use any of the archive record fields with the $current tag.

Gary

[sailmich]

Luminosity isn't in the archive records. According to the docu my device WH3080 should deliver   (http://weewx.com/docs/hardware.htm#fousb_data28). Is that a bug or do I have to change settings?

[gjr80]

Not a fine offset expert but have you set data_format = 3080 in weewx.conf? Refer the fousb notes in the Hardware Guide (http://weewx.com/docs/hardware.htm#fousb_notes). Any change will require a WeeWX restart.

Gary

[sailmich]

Weewx.conf was  Model = WH3080 and I changed it to data_format = 3080 no different at all. I just get UV and radiation which is the same sensor for luminosity. Is there something wrong with fousb driver?

Mike

[gjr80]

As far as I am aware the fousb driver works fine with a 3080, certainly I recall posts from other users that have received luminosity data. The fousb stations have occasional USB issues but that is more of a case of lost/locked comms rather than lack of luminosity data. You might try stopping WeeWX and using wee_device to query your station and look at the history data (is luminosity data being recorded). The link I posted previously has details on the commands to run.

Failing that you might need someone experienced with fousb and 3080 stations.

Gary

[sailmich]

Answer to myself. Maybe someone is running in the same problem.

Radiation is calculated by fousb driver.

You can find it in fousb code at line 598 'radiation' : ('illuminance', 0.01075), # lux, weewx wants W/m^2

What confused me is in documentation it's called luminosity while in fousb driver named illuminance.

So I just switch the factor to 1.0 and now I get the same value as displayed under LIGHT in display of my WH3080 weatherstation.

Now controll of my blinds without the factor should be easier.

[Greg Troxel]

sailmich <mm24...@gmail.com> writes:

> Answer to myself. Maybe someone is running in the same problem.
> Radiation is calculated by fousb driver.
> You can find it in fousb code at line 598 'radiation' : ('illuminance',
> 0.01075), # lux, weewx wants W/m^2

irradiance (often called insolation) is power, and is in W/m^2.

If your unit

> What confused me is in documentation it's called luminosity while in fousb
> driver named illuminance.

luminosity is not a word typically used in lighting.

illuminance measures light according to human perception. The units are lux.

> So I just switch the factor to 1.0 and now I get the same value as
> displayed under LIGHT in display of my WH3080 weatherstation.
> Now controll of my blinds without the factor should be easier.

Are you seeing values near 100,000 to 200,000 at noon in full sun? If
so that is plausibly illuminance in lux.

If you peak around 1000, that is more like irradiance in W/m^2.


It seems best for weewx to record illuminance or irradiance as measured
by the station. One can't really convert between them in a reliable
way.

[sailmich]

I agree best is take what you get out of a sensor! Thats the reason why I changed the factor to 1! In the display of my weatherstation was 12.6 kLux at cloudy sky 7pm. So thats what you called illuminance and what also have the same name in fousb driver but not in the documentation. I'm not a native so I don't know if a technical word make sense or not. I got now the same value on the display of my weatherstation and on my Rpi. Now I'mhappy!

Thanks for your explanation.

[Greg Troxel]

sailmich <mm24...@gmail.com> writes:

> I agree best is take what you get out of a sensor! Thats the reason why I
> changed the factor to 1! In the display of my weatherstation was 12.6 kLux
> at cloudy sky 7pm. So thats what you called illuminance and what also have
> the same name in fousb driver but not in the documentation. I'm not a
> native so I don't know if a technical word make sense or not. I got now the
> same value on the display of my weatherstation and on my Rpi. Now I'mhappy!
> Thanks for your explanation.

12600 lux (usually it's lower case) is quite plausible for cloudy at
7pm.

What I meant is that if your device measures illuminance in lux, then it
would be nice to have the column in the archive table be illuminance and
not "radiation".

Illuminance is a technical term in English. I had forgotten, but
luminosity refers to the relationship between irradiance and illuminance.

Wikipedia gives direct sunlight as 10 000 and 100 000 lux, variously.
100 000 matches my memory, and your light level was much less than full
sun.

These links are a bit hard to read but may be interesting:

https://en.wikipedia.org/wiki/Illuminance
https://en.wikipedia.org/wiki/Irradiance
https://en.wikipedia.org/wiki/Sunlight
https://en.wikipedia.org/wiki/Solar_irradiance