Cumulus Support

I finally received my GW1003 weather station from Ecowitt yesterday so I thought I would just do a quick report on what I have found out so far.

For testing, I built a new "clean" instance of CumulusMX on a spare Raspberry Pi 3 Model B, running Raspbian Buster, Mono 6.8.0.105 and Cumulus MX 3.5.4 b3075.

The GW1003 kit includes the following sensors / equipment:

GW1000 - WiFi Gateway with Indoor Temperature, Humidity and Barometric Sensor
WS80 - Ultrasonic Wind Speed&Direction, Solar Radiation & Light, Temp & Humidity 6-in-1 Sensor
WH40 - Rain Gauge Sensor

I also added in a WH57 - Lightning Detection Sensor. (Just for a bit of fun)

First part to set up was the GW1000 gateway. This is much smaller in physlical size than I anticipated but fits neatly in to a standard USB "all in one" electrical plug or alternatively you could use a USB extension cable if you want to locate it away from your electrical supply. Set up was quite easy. You need to download the WS View app for either IOS or Android and follow the instructions in the app. Quite easy to do and it was hooked up to my wifi network within minutes. One thing missing is the ability to assign a static IP address to the GW1000. I assigned the address using DHCP address reservation in my router. You dont actually need to do this as the WS View app keeps track of it if the IP address changes. CumulusMX also has the auto-detect feature option for the GW1000 gateway once you have configured Cumulus MX for an Ecowitt station. I just like to have fixed addresses for certain bits of kit so I dont have to go looking for them on the network if there is an issue to do basic things like "ping".

Next, I configured Cumulus in the standard way. I am not uploading to my website yet so just configured a basic set of parameters. Once configured I restarted Cumuslus and it automatically detected my GW1000. So far so good.

Next came the sensors. This was simply a matter of installing the batteries into each one and within seconds they were connected to the GW1000 and reporting data. This was being picked up in Cumulus on my local machine. The sensors appear to be extremely well made, very sturdy and solid. However, the funnel on the rain gauge (its a push and twist mechanism) doesn't "click" into place, is quite loose and can easily be twisted. Maybe needs a bit of tape on the underside. It has a small grill that fits inside the funnel to catch any debris, leaves etc that may fall in there and there doesnt appear to be any major holes for insects to crawl inside. Time will tell.

The actual set up, once I had Cumulus installed on my PI, took around 30 minutes.

You can view weather stats on the WS View app and also review your connected sensor. Some show battery levels and all show wi-fi signal strength. The app is not brilliant, it gives a very basic display of the conditions. You can also calibrate your sensors via the app, and its needed to adjust absolute / relative pressure differences so that the correction is made.

Before climbing up on top of the shed I tempoarily installed the sensors outside. Parts of my old Maplin station are still working and when comparing current values they do vary slightly, temperature, humidity, pressure by about 0.5 of a point but they are in different locations outside the house so potentailly could be why. Having said that my Maplin station is 7 years old so may be on its last legs. I cant compare the wind speed / direction as that bits not working on my old station. We have had some rain today and there is 0.3mm difference with the older station showing the higher amount. Again, its 7 years old and is probably not the most technologically advance instrument available.

As for the lightning detector, this was just for a bit of fun. No storms yet although I did notice that Cumulus shows a detection on 7th Feb 2106 158 miles away. This doesnt show on the WS View so maybe this is just a little glitch in Cumulus, or maybe I just avoid travelling 158 miles from the house in 86 years time.

You can configure the GW1000 to upload data to various weather services. I already do this through CumulusMX so for the time being wont get in to that.

I guess the proof of the pudding will be when I get the sensors and the GW100 permanently located, but until then, so far I have no major complaints.

I got mine on Monday and the rain collector is on the garage roof and the other part is now on the roof. Interesting bit of kit and I had to calibrate the pressure as it was a fair bit off out of the box.

So today we had rain for the 1st time in yonks.. the Ecowitt reported 0.3mm @1.2mm/hour the Davis Vue, 0.8mm @ 2mm/hr. they are next to each other.. which one is right????

edit : I was also hit with a £50 import charge.. tossers!!!! Might try to contest it.. or maybe not!

My pressure seems to be ok, although cant take an accurate measurement as I checked on 3 local RAF stations, there is a lot round here, and they vary quite a lot. All are within a 10 - 15 mile radius of my location but my GW1003 is sitting somewhere in that range. My local BBC weather forecast gets its data from RAF Holbeach which is 20 miles as the crow flies but that was last updated at 2pm this afternoon so absolutely no good whatsoever. I picked some other spots within 20 mile radius and checked on BBC, some updated more recently and I again sit somewhere mid-range so have to say I am happy with it. Compared to my 7-year old Maplin station the GW1003 is .6hpa higher so more or less accurate enough. I assume you adjusted the relative pressure to account for your altitude.

I have also noticed today that the rain gauge does not record as much rain either, 2.0mm on the GW1003 and 4.5 on the Maplin. I did notice on the GW1003 that the rain sits on the funnel and not all drops into the tipping bucket. I dont know exactly how much but if its a fair amount it could make a difference. I did see this on the Ecowitt website http://www.ecowitt.com/news/60.html, makes me wonder if they are suggesting this as an improvement. Will try and get hold of some teflon spray, looks like a good idea anyway.

My unit is still "under test", rain gauge screwed on an open area fence and main unit sat on patio table. Plan to install fully at the weekend.

As for import charges, I got hit with those as well, £12 was FedEx handling fees, there will be import duties plus VAT@20% on goods + shipping costs. Unfortunately there is little you can do about it.

Andy

Thanks!
I'll order mine shortly
The VAT in Sweden is 25%
PS
any thoughts regarding the Note

There’s a built-in heat plate in the 6-in-1 sensor package body, if the lowest temperature at your place is below -3°C, or 26.6°F, and the weather is mostly snowy or rainy, then you may need to activate the heater by supplying a 5V/1A power to the sensor heating element for melting accumulated snow or ice

Interestingly, this morning my old Maplin station recorded 0.0mm rain overnight and my Ecowitt 0.9mm at 5.30am. Judging by the concrete patio at 6.30 when I woke up, we didnt have any rain. When I looked at the funnel on the GW1003, again there was a large amount of rainwater sat on the funnel which hadnt run down in to the tipping mechanism, on my Maplin one there was none. I am suspecting that rain collecting on the funnel is the problem and eventually, maybe a small breeze disturbs it and it runs down in to the tipping bucket. Have ordered some Teflon spray.

@rogerthn,
Speak with Lucy at Ecowitt Support, she is happy to "help" with import costs.

Regarding the heating plate, I am not sure if I need this but I ordered a cable for it anyway, just in case. I also ordered one of these devices from Ebay
https://www.ebay.co.uk/itm/12V-220V-Dig ... 2749.l2649

I got the 220V version which in theory I can connect to a mains power socket, plug in a USB adaptor and it should turn on and off automatically when the temperature is between a certain range. Need to rig up a light to it as well to get some indication when its on to ensure its not on when it should be off otherwise it will burn out the heating plate.

Andy

You can contest the FedEx charges - I did every time and got my £12 back.

http://blog.adamowen.co.uk/dont-pay-fed ... ment-fees/

Thanks Mapantz I will give this a try. I already paid the invoice but will push to get their charges refunded.

Andy

Back to the rain gauge. After a short heavy shower my Maplin gauge registered 3.6mm of rain and my GW1003 1.9mm.

10 minutes after it had stopped raining I took the attached photo. Thats a lot of rain that hasnt been measured. I have also taken the "debris filter" out to see if that helps as there are rain droplets stuck in there as well.

Will wait for the next downpour.

You need something vibrating against that funnel to get those drops moving!

That will eventually stop happening. However, I used some silicone spray on mine. Rain readings are within a mm of my Davis VP2, which is acceptable.

Big Daddy wrote: ↑Thu 30 Apr 2020 7:24 am ...
@rogerthn,
Speak with Lucy at Ecowitt Support, she is happy to "help" with import costs.

Regarding the heating plate, I am not sure if I need this but I ordered a cable for it anyway, just in case. I also ordered one of these devices from Ebay
https://www.ebay.co.uk/itm/12V-220V-Dig ... 2749.l2649
...

Andy

Thanks!
I've already had some chat with Lucy and I'll for sure ask for some "help" with import costs

I've ordered a 220V Temperature Controller Thermostat Control Switch and it will take some time before it is in Sweden
"Estimated delivery Sunday, May 17, 2020 - Sunday, Jul 19, 2020" but even if it's delayed it should be here before the temperature is below 0 °C again

Interesting to see what solution is the best regarding the "rain issue"

Roger

Big Daddy wrote: ↑Wed 29 Apr 2020 10:11 pm My pressure seems to be ok, although cant take an accurate measurement as I checked on 3 local RAF stations, there is a lot round here, and they vary quite a lot. All are within a 10 - 15 mile radius of my location but my GW1003 is sitting somewhere in that range. My local BBC weather forecast gets its data from RAF Holbeach which is 20 miles as the crow flies but that was last updated at 2pm this afternoon so absolutely no good whatsoever. I picked some other spots within 20 mile radius and checked on BBC, some updated more recently and I again sit somewhere mid-range so have to say I am happy with it. Compared to my 7-year old Maplin station the GW1003 is .6hpa higher so more or less accurate enough. I assume you adjusted the relative pressure to account for your altitude.

Here is my input on your station. I may need a bit of your input to perfect this.

You seem to be at I'm guessing 5 meters elevation (your barometer - location of GW1000).
The GW1000 Rel Offset should then be set to 0.6 hPa (as that corresponds to 5 meters of elevation)

Before adjusting that ...for reference your current WU, PWSweather, and WeatherClould seem to all indicate that your reporting pressure is about 2 hPa too high. This will need fine tuning after you enter the 0.6 hPa Rel Offset. That fine tuning you would then do with the Abs Offset.

I would recommend using EGXC (Coningsby(RAF), EN, UK)
https://aviationweather.gov/metar/data? ... e=&hours=0

The distance to this airport should not be a problem if you select a time to fine tune calibrate when isobars pass through both your location and EGXC. I like using Windy.com to see isobars. The isobars are not on by default but you can turn them on in their map. I also set the map to show pressure in inHg because it has more precision than their rounded hPa which is in whole hecto Pascals.

Sadgit wrote: ↑Wed 29 Apr 2020 6:39 pm I got mine on Monday and the rain collector is on the garage roof and the other part is now on the roof. Interesting bit of kit and I had to calibrate the pressure as it was a fair bit off out of the box.

Unless your location is at elevation 0 then the barometric pressure will be off out of the box. The higher your elevation then the more off it will be. The station has no way of knowing your elevation. You have to give it your elevation by entering in the Rel Offset (Relative Offset).

I use the following site to calculate the offset:
https://keisan.casio.com/exec/system/1224579725

Leave all numbers as they are. Only enter in your elevation (of your barometer not your anemometer). This is the total elevation of your location plus how high off the ground your GW1000 is. Do not change the temperature no matter how tempting that may seem. Then click on the Excecute button.
Then subtract 1013.25 - resulting Atmostpheric pressure P. The answer you get to that subtraction will be the Rel Offset value you need to use. You never touch that again. Realize you are doing this even before you look to see what the local METAR pressure is. That doesn't matter yet. That will be your next step after you enter this Rel Offset. Then Step 2 is to look at the local METAR and decide how far off you are. You then adjust Abs Offset (the Absolute Offset) by however much your Relelative reading is. The change you enter for Abs Offset will also affect the Relative reading on your Live data.

In Summary:
Adjust Rel Offset once...just to indicate your elevation
Then fine tune only adjusting the Abs Offset.

When you adjust Abs Offset you aren't matching Absolute to the METAR rather you are adjusting Absolute to effect a change in your Relative...so that you can match the Relative to the METAR.

@galfert:
@Sadgit:
I don't really understand what you are doing / saying here (and yes I do understand the calculation that is not my point)?

What value do you want to be taken by CumulusMX for storage? Sea level or the actual measured value? How can a user be sure what value he is looking at?

Calibration of the pressure - Sadgit's question - does not mean calculating it to sea level. It means correcting the device value with a standardised barometer or institute value. Just like you would calibrate the temperature reading with a standardised thermometer. Calculation of pressure to sea level is really very different to calibration!

Thanks for the info.

I am at 16ft elevation so roughly 5m and have my Rel pressure already set to an offset of +0.6 but as you noted it does look as if my Abs pressure is 2 hpa out compared to Conningsby.

Using your information I have adjusted my pressure in line with Conningsby which is slightly different to what Windy shows but will keep making minor adjustments if needed to get it right.

Hans,
My understanding is that pressure is always meteorogically reported as the Relative (sea level) figure, this way you get a constant "global" reading. If you report Absolute (station) then it could vary greatly even within a short distance as the house on top of the hill will report a different (lower) value to the house in the valley.

I agree, the calibration is to ensure that the Abs pressure is calibrated correctly, mine was roughly 2.0 hPa too high. Now I have the Abs pressure calibrated and my Relative offset, it reports what the pressure would be at sea level.

Andy