Matthew Wall's Weewx-netatmo driver (thank you Matthew for creating it!) 
collects the data from the Netatmo server by using the /getstationsdata 
method provided by the Netatmo API. The behaviour of this method for the 
data provided by the  rain gauge is weird. Indeed, as a few others noticed, 
summing up over one day the rain data reported by the /getstationsdata for 
each observation period you do not have the same amount of rain given 
directly by the station for the day (that, by the way is wrong as well but 
to a minor extent). Usually you have a much lower value . The reason for 
this is that the station sends the rain data to the server every 10 
minutes. Each data packet reports the rain fallen  during  2 five minute 
observation periods but the /getstationdata method sends back the rain for 
just one of these periods the other is simply dropped. You can see evidence 
of this in the attached picture where I compare the data of my station 
downloaded from the netatmo.com website as an xls file (that are correct) 
with those reported by the /getstationsdata (on the right) where each 
second "five minutes"data are missed. The error is greater during heavy 
rain. Indeed, there is no error in some cases, e.g. when during the missed 
observation period we have no rain at all. 

In conclusion, using Weewx with our Netatmo weather station results in 
wrong data for rain measurement and the error can be very high (50% and 
more), .

I think that the problem could be fixed by using the /getmeasure method in 
place of the getStationdata one, because with this method you can access 
the data relevant to whatever 5 minutes time inetrval you specify in the 
query. Unfortunately, my software developping skills are not strong enough 
for forking Matthew Wall's driver.

Matthew, are you around?

Regards

Emilio

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