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TFA wind sensor
Posted: Monday 27 August 2018 16:33
by stuiow
Quick question, what units do the tfa anemometers output in, MPH/KPH/MS?
Cheers
Sent from my SM-G955F using Tapatalk
Re: TFA wind sensor
Posted: Wednesday 05 September 2018 20:29
by ds106
Hi,
Ruud v Gessel's "Cresta weather sensor protocol" describes Windspeed and Windgust as mph. As I can see RFLink passes sensor mph value as kmph to domoticz, rfxcom passes calculated kmph from sensor mph.
- Win1.jpg (35.7 KiB) Viewed 3490 times
Regards Götz
Re: TFA wind sensor
Posted: Monday 12 November 2018 14:59
by koenkooi
Domoticz seems to do something different here:
It gets '8' as data:
- Schermafbeelding 2018-11-12 om 14.53.04.png (22.88 KiB) Viewed 3247 times
And displays '2.9 km/h'
- Schermafbeelding 2018-11-12 om 14.53.10.png (50.42 KiB) Viewed 3247 times
The code has this:
Code: Select all
//Wind
if (m_windunit == WINDUNIT_MS)
{
m_windsign = "m/s";
m_windscale = 0.1f;
}
else if (m_windunit == WINDUNIT_KMH)
{
m_windsign = "km/h";
m_windscale = 0.36f;
}
else if (m_windunit == WINDUNIT_MPH)
{
m_windsign = "mph";
m_windscale = 0.223693629205f;
}
else if (m_windunit == WINDUNIT_Knots)
{
m_windsign = "kn";
m_windscale = 0.1943844492457398f;
}
else if (m_windunit == WINDUNIT_Beaufort)
{
m_windsign = "bf";
m_windscale = 1;
}
Why does domoticz think the data is in decimeters/second?
Re: TFA wind sensor
Posted: Tuesday 13 November 2018 8:16
by Toulon7559
In Domoticz speed expressed as 0.1m/s is aspect of definition.
See
https://www.domoticz.com/wiki/Domoticz_ ... L%27s#Wind
Only reason I could imagine, is that then the practical transfer values can be expressed as integers.
Re: TFA wind sensor
Posted: Tuesday 13 November 2018 13:45
by koenkooi
So is the '8' in the data overview the value read from rfxcom (presumably in km/h) or the processed value? I ask because the '8' is a lot closer to the 10km/h from the local weather report than the 2.9km/h domoticz displays.
I don't have a different (calibrated) anemometer to compare against, so domoticz could be doing the right thing already.
Re: TFA wind sensor
Posted: Tuesday 13 November 2018 15:44
by Toulon7559
If you are using Nexus' USB-interface, that interface is according to TE923:
this documentation might apply for read-out.
Reading
this documentation indirectly you can find practical info on Nexus' data protocol.
Re: TFA wind sensor
Posted: Tuesday 13 November 2018 19:30
by koenkooi
I'm using the 433MHz sensors with an rfxcom transceiver connected to domoticz.
Re: TFA wind sensor
Posted: Sunday 18 November 2018 14:35
by sincze
I noticed the difference as well and notified the stunt team on 28_7_18 unfortunately no response. But hopefully fixed in r49.
- Windmeter.JPG (64.84 KiB) Viewed 3119 times
Re: TFA wind sensor
Posted: Wednesday 28 November 2018 20:37
by Toulon7559
@stuiow
Which interface are you applying to read the TFA_Nexus anemometer?
By accident (while looking for something completely different) I can confirm the observation by
ds106 that in Domoticz it
seems to make difference over which interface you read windspeed from TFA_Nexus
a) over the Console's TE923 USB-interface, or
b) wireless by RFXCom or
c) wireless by RFLinkGateway:
- the readouts a) and b) from the TE923-interface, respectively from the RFXCom
usually agree
- the readout c) through the RFLinkGateway [in my case R46] shows much lower values [meanwhile this 'possible bug' reported to Stuntteam],
possibly (?) a factor 1.6 due to output as mph vs. kmh
Furthermore, (similar to reported by
sincze) generally the values coming from my TFA_Nexus' anemometer are lower than those coming from a co-located WS7000-anemometer (which I better trust, because better quality, although aged).
Just raises the question: which wind speed is true & correct?