Topic: New for 2020 - OEM Davis Sonic Anemometer

[mauro63]

I think for a VP3 to exist only two things need to happen.

• Move from LSS to I²C for sensors.
• Provide a new console via low cost tablet or a smart app for the WLL. This is something that does not need to come from Davis. All the requirements are already there with the WLL API, and there is currently progress in this aspect with the very first app in development which is Daviswll.

I hear those of you advocating that having I²C is no big deal for most customers. BUT the LSS sensor supply is limited and no longer in production. No matter how many LSS sensors Davis has hoarded away, the supply is finite. Therefore Davis just has to be designed the next thing with I²C support. I VP3 or a VP2 with I²C support is evident at some point.

I absolutely agree, but this is a risky choice, an ISS with I2C protocol will allow users to choose the preferred sensors, without need to buy Davis sensor replacement, improve performances with better sensors, more little and, also better solar radiation shield, not possible now
This could be a very good upgrade if we take a look at performances, but a bad choice in a commercial view

sorry for my english

Mauro

[Mattk]

Any thoughts on how these would work with freezing rain? Most I've seen is around .50" this year.
The standard anemometer does poorly and the freezing rain events sometimes are a precursor to a blizzard so I end up with no wind data. Frustrating. 

A proper Ultrasonic anemometer requires a lot of power for freezing conditions and I doubt there is enough in a little solar panel to be useful?

[92merc]

With the design of this unit, it has a cap on it to protect from "most" freezing rain.  All it needs to do is move the solar panel off the top and onto the side.  That will help keep snow off it and allow it to be angled into the sun.

[CW2274]

All it needs to do is move the solar panel off the top and onto the side. 

In the literature they state "It is relatively unobtrusive and has a simple modernistic shape" so I'm guessing they want to keep it "pretty".

[mauro63]

but, until now, I didn't understand where to download the 2020 catalog 

Mauro

[johnd]

I absolutely agree, but this is a risky choice, an ISS with I2C protocol will allow users to choose the preferred sensors, without need to buy Davis sensor replacement, improve performances with better sensors, more little and, also better solar radiation shield, not possible now
This could be a very good upgrade if we take a look at performances, but a bad choice in a commercial view

This doesn't really work I'm afraid. Every I2C digital sensor will have its own micro API I presume and unless/until someone works out how to reverse engineer and reprogram the ISS firmware appropriately then a different sensor won't be able to yield any sensible readings. And that's not the end of the task - the solar/UV inputs are known to have 3v linear/analogue inputs, yet I can't think of a single third-party sensor that's been released to use these inputs and yield meaningful readings.

Just FAOD I'm not disagreeing for a moment that as and when a redesign of the VP2 SIM board is deemed desirable a move to I2C be made (assuming that there are no consequential issues, eg higher power drain during a T/H read). It's just a question of what priority this change is assigned. And even if it were made, it could well emerge as a further tweak to the VP2 design rather than in a (somehow) completely new VP3 design.

[twcmaster]

With the design of this unit, it has a cap on it to protect from "most" freezing rain.  All it needs to do is move the solar panel off the top and onto the side.  That will help keep snow off it and allow it to be angled into the sun.

Rainwise also sells a Davis compatible version of the LCJ that does not have a solar panel, but could be wired up to one. Unfortunately, the price is even more than the solar panel model.

Non-Solar Powered (DVC):
https://rainwise.com/products/detail.php?ID=6954

Solar Powered (DZP):
https://rainwise.com/products/detail.php?ID=9005

[fkapp]

How does the LCJ one perform in the field?

[davidg_nz]

I hear those of you advocating that having I²C is no big deal for most customers. BUT the LSS sensor supply is limited and no longer in production. No matter how many LSS sensors Davis has hoarded away, the supply is finite. Therefore Davis just has to be designed the next thing with I²C support. A VP3 or a VP2 with I²C support is evident at some point.

Any source for the SHT31-LSS no longer being in production? It should be pretty easy for Davis to release a new SIM PCB that speaks i2c instead of Sensibus (could be as simple as a firmware change given how similar i2c and sensibus are) so the fact they've not bothered suggests they're not concerned about availability of Sensibus parts. Probably they're still available from Sensirion as a special order if you're willing to buy enough of them.

I think even if they did switch to i2c it wouldn't be a Vantage Pro3 thing - just a new SIM PCB revision users wouldn't need to know about until it comes time to replace their temp+humidity sensor.

A Vantage Pro3 seems kind of unlikely really. Davis might just keep iterating on the Vantage Pro2 as they have done for the last few years with various incremental upgrades that can be retrofitted to older stations as necessary.

[galfert]

Regarding LSS sensor discontinuation from Sensirion:
You can see in the dataheet specs that the LSS version is not listed any more. Sensor parts distributors like Digikey and Mouser no longer have the LSS sensors. I have also read from other users here that production on LSS has been discontinued (they mentioned having has some sources for this information). I have communicated with Sensirion regarding the LSS discontinuation and asked them if they know what Davis would do now or if there is some secret to contract to keep providing Davis with LSS sensors. To which Sensirion responded that they had no idea what plans Davis has and was not privy to any contract with Davis to keep supplies of LSS sensors. This was not just a one off conversation with Sensirion, it was a much engaged conversation dealing with sensors quality, sensor performance, comparisons among competitors to Sensirion, OEM conformal coatings and much else. They were very interested in providing good information back with several questions posed and they knew from the beginning that I was inquiring in all these things for all of users here at wxforum.net. So it very much was not a canned brush off response. I even got a direct contact and they asked to keep informed with new information and I likewise from them.

I agree that Davis could implement I²C support whilst calling it a VP2. But that would be unwise because as you said as sensor replacement time comes then knowing if you need a LSS or I²C replacement would be more confusing. If the station owner knew they had a VP2 or a VP3 then it would be easier to get the correct replacement parts. The mistake would be calling the new model a VP2 because that would create another Green Dot headache.

[mauro63]

You can download the new 2020 catalog at link below 

https://www.meteoshop.gr/datafiles/file/PR57_2020_Catalog_Global_compressed.pdf

Mauro

[johnd]

I agree that Davis could implement I²C support whilst calling it a VP2. But that would be unwise because as you said as sensor replacement time comes then knowing if you need a LSS or I²C replacement would be more confusing. If the station owner knew they had a VP2 or a VP3 then it would be easier to get the correct replacement parts. The mistake would be calling the new model a VP2 because that would create another Green Dot headache.

It's rather an esoteric point to debate, but I still don't agree with this (ie that a revised VP2 with I2C would need to be called a VP3 if that were the only change). There are various examples of breaking changes in the VP2 lineage and, perhaps more to the point, it might (?) be possible to add I2C in a way that allowed any Davis T/H sensor to be used. For example, it always used to be true (not checked it recently but AFAIK it's still the case) that you can connect the old analogue T/H sensor or a T-only sensor like 6475 or 6477 to a more recent VP2 ISS and it would read fine. So the SIM board is obviously somehow sensing which type of T/H sensor is attached.

[Chiky33]

Hello,

I had for 1 year the SONIC-ANEMO-DZP anemometer which has the solar panel above.

Very disappointed:

I live in Switzerland near lakes and fall / winter there is often fog. The solar panel can no longer charge the battery correctly and after 3-4 days the sensor switches off ...

LCJ exchanged the anemometer against the model:

- SONIC-ANEMO-DVC which accepts a voltage of 2.7 - 35V

To make the solar power supply with a correct battery, I took the Davis 6612 Heavy Duty Solar Power kit and solder a socket on it.

=> No more breaks in foggy weather.

The anemometer is on the same mat (10 meters) and next to the analog model:

- http://kuffner.meteonet.ch/ =>

- LCJ anemometer graph => Wind Speed ​​2
- Basic Davis anemometer graph => Wind Speed ​​1

Differences between the two:

- http://kuffner.meteonet.ch/daily.php

Or on :

- https://www.weatherlink.com/ =>

Cressier / NE station (Chemins des Marais)

Have a good day.

[ValentineWeather]

Chiky33 nice report and info what to expect. 
The solar only works well when the sun is out.    I know.  I also have issues with the solar FARS fan after a few days of no sun. I'm sure others do too they just don't know it because the temperature keeps on working but when the wind speed stops that gets everyone's attention.

[fkapp]

I agree that Davis could implement I²C support whilst calling it a VP2. But that would be unwise because as you said as sensor replacement time comes then knowing if you need a LSS or I²C replacement would be more confusing. If the station owner knew they had a VP2 or a VP3 then it would be easier to get the correct replacement parts. The mistake would be calling the new model a VP2 because that would create another Green Dot headache.


It's rather an esoteric point to debate, but I still don't agree with this (ie that a revised VP2 with I2C would need to be called a VP3 if that were the only change). There are various examples of breaking changes in the VP2 lineage and, perhaps more to the point, it might (?) be possible to add I2C in a way that allowed any Davis T/H sensor to be used.

For example, it always used to be true (not checked it recently but AFAIK it's still the case) that you can connect the old analogue T/H sensor or a T-only sensor like 6475 or 6477 to a more recent VP2 ISS and it would read fine. So the SIM board is obviously somehow sensing which type of T/H sensor is attached.

Would be interesting if someone could test this by plugging in the 6475 or 6477 to a recently purchased VP2.
Will confirm "backwards comptability" and if this is the case will help with a natural evolution of sensors to new SIM vs needing to buy all new station. I am sure they will take this approach or will have many unhappy customers if and when board replacement is needed.

[davidg_nz]

It's rather an esoteric point to debate, but I still don't agree with this (ie that a revised VP2 with I2C would need to be called a VP3 if that were the only change). There are various examples of breaking changes in the VP2 lineage and, perhaps more to the point, it might (?) be possible to add I2C in a way that allowed any Davis T/H sensor to be used. For example, it always used to be true (not checked it recently but AFAIK it's still the case) that you can connect the old analogue T/H sensor or a T-only sensor like 6475 or 6477 to a more recent VP2 ISS and it would read fine. So the SIM board is obviously somehow sensing which type of T/H sensor is attached.

Looking at the datasheets and some points on the internet I suspect this can be done. The LSS and i2c parts are very similar - data and clock are on the same pins, supported voltage ranges are the same. Only difference seems to be in the signalling. I wouldn't be surprised if the only difference between the LSS and i2c parts was firmware.

On the microcontroller end it probably comes down to how much free flash memory they've got. Given the parts are electrically compatible it shouldn't be hard to on startup try reading from an SHT31-LSS and if there is no response turn on i2c and try reading from an i2c SHT31.

[davidg_nz]

Would be interesting if someone could test this by plugging in the 6475 or 6477 to a recently purchased VP2.
Will confirm "backwards comptability" and if this is the case will help with a natural evolution of sensors to new SIM vs needing to buy all new station. I am sure they will take this approach or will have many unhappy customers if and when board replacement is needed.

This backwards compatibility is only really helps people who for whatever reason need to replace their SIM PCB without replacing the temperature+humidity sensor. Probably not many people in this category.

People who need to replace a failing temperature+humidity sensor are probably much more common. They need forwards compatibility from the SIM. Once the current Sensibus sensors are replaced by newer i2c sensors unless the SIM they have already supports i2c they'll need to replace the SIM PCB at the same time as installing their first i2c sensor. For some this could be quite expensive - the NZ distributor at least seems to charge double the US price for everything.

[johnd]

This backwards compatibility is only really helps people who for whatever reason need to replace their SIM PCB without replacing the temperature+humidity sensor. Probably not many people in this category.

I suspect fkapp was simply wanting confirmation of the principle that the ISS SIM board is designed to accept more than one type of T/H sensor. But thinking about it this must still be true - the 6372 Temperature Station which was a current product until very recently consists of an ISS SIM board + 6475 temperature-only sensor. If I get a moment sometime I'll check with the one of the old analogue T/H sensors just to extend the principle.

[fkapp]

Thanks John.
If this works for fun would be to give a still in good working order 7859 sensor a run and see how compares.
I know is a bit out there....

[johnd]

If this works for fun would be to give a still in good working order 7859 sensor a run and see how compares.

Just to be clear, 7859 is the old WMII analogue T/H sensor IIRC - I haven't seen one of those in working condition for many years and it's definitely not VP2-compatible AFAIK. I was referring to the original VP2 analogue sensor whose part number escapes me right now, but which is something smaller and rather different from 7859.

[bro931]

Oh bummer. So why do you say unsurprisingly no VP3?

Because - while I'm always prepared to be proved wrong, but as I've consistently said here - I've not picked up any signs whatsoever that a 'VP3' is pending, or even on the launch roadmap for the next year or two (though Davis are pretty good at keeping early stage products very quiet). Apart from anything else, it's not at all clear to me what would be different about a VP3 from a VP2 - especially now that the tipping spoon rain gauge and (ultra)sonic anemometer are available for the VP2. I know there are some folk that would like 'real' I2C for the T/H, but for maybe 95% of Davis buyers it's not an issue. There is the console question of course, but right now and as we've often discussed here it may be that a software/tablet + WLL solution turns out to be the answer here. TBH I'm more concerned about the lack of an inexpensive LoRa gateway, but this is probably more of a US vs Europe thing (in their take-up of LoRa technology I mean).

I guess this means than no major product launches this year in addition to the items in the 2020 catalog?

It's unlikely, though not totally unknown. And I wouldn't worry too much about the 2020 catalogue not being public yet, though I dare so someone will post a link before long. Other than a new (undated AFAICS, which is interesting) front cover, it's very much like the 2019 one. And the headline new products are all mentioned in this thread.

I would like to reinforce what John said.  Davis keeps throwing minor improvements at the VP2 and thus I don't see a chance for a VP3 to be introduced anytime soon either.  It would say it is either years down the road or possibly never?  My advise for people on the fence waiting for a VP3 to come along, don't bother.

Totally agree about NOT waiting for VP3.  Talked to a Davis rep at an AMS Annual Meeting years ago and was misled to believe a new system was coming out that year (2015?).  Still nothing.  But my 2009-vintage VP2 is still working, so their loss, not mine.

[SwissWetter.shop and MeteoMap.cloud]

Any thoughts on how these would work with freezing rain? Most I've seen is around .50" this year.
The standard anemometer does poorly and the freezing rain events sometimes are a precursor to a blizzard so I end up with no wind data. Frustrating. 

A proper Ultrasonic anemometer requires a lot of power for freezing conditions and I doubt there is enough in a little solar panel to be useful?

Hello to the round

I am new here in this Forum and have just read the discussion here.

It's not just about "freezing rain." It is also about the following weather phenomena:

- Fog at Temps < 0°
- Wind with snowdrifts
- very low temperatures with ice formation
- Snowfall and windy conditions

I had some EXTREME experience with the Vaisala WXT510 a few years ago. This sensor was heated - but still too little. And this with a Finnish sensor ! We found a replacement in the WS425, which is heated with about 60W at the sensor arms.

Reason: Even the smallest ice formation falsifies the measurement and generates "storm winds" which did not exist at all.

How Davis can bring such an ultrasonic sensor on the market is a mystery to me. Even at non-alpine locations there can be ice formation (ground frost etc.). Either Davis doesn't know yet what they are getting into, or they have invented a completely new technique that ignores ice formation and snow crystals.

Ultrasonic Sensor with 240W (!) heating power for extreme conditions:

https://swisswetter.shop/VENTUS-X-UMB-von-Lufft-mit-Ultraschall-Windsensor-mit-erweiterter-Heizung

You see: An ultrasonic sensor stands and falls with the heating power.

Best regards
Markus

[ValentineWeather]

Thanks, Markus for the information on your experience. I have a strong feeling you are correct unless they have reinvented something these low powered ultrasonic sensors may be nothing but trouble for any climate outside of mild coastal areas that rarely freeze. 
 

[vsakalis]

Does someone inform me where I can buy the LCJ sonic Anemo DZP.
I cant find it in an e-shop of EU (not UK because of taxis from 2021)
Thanx