[danner]

... Is there no way to display inches?

// --------------------------------------------------------------------------------------
//   Define data display units
// --------------------------------------------------------------------------------------
#define Date_Time_Format 1     // 0 for dd-mm-yyyy, 1 for yyyy/mm/dd
byte Temp_Display_Unit = 1;    // 0 for ºC, 1 for ºF
byte ATM_Display_Unit  = 1;    // 0 for mBar, 1 for inHg
byte Rain_Display_Unit = 0;    // no setting, always mm
byte Wind_Display_Unit = 1;    // 0 for Km/h, 1 for mph, 2 for m/s, 3 for Knots

I know that commonly the rainfall in USA is expressed in inches. Unfortunately for USA users, the WeatherDuino can only display the rainfall (and rainfall rate) in mm. I don't remember where but there are a discussion on the forum about this matter. The main reason is about precision, to display 0.1mm of rain in inches, we need to use at least 4 decimal places.

2 decimal places is what we normally use. 0.2mm could be rounded up to 0.01". Can any rain gauge actually measure 0.1mm of rain? I would think the bucket tip would require a lot more rain than 0.1mm.

[werk_ag]

... Can any rain gauge actually measure 0.1mm of rain? I would think the bucket tip would require a lot more rain than 0.1mm.

I have referred 0.1mm just as a reference value, however there are some rain gauges that can measure 0.1mm of rain, and 0.2mm are common. The metric versions of the Davis rain gauges, all use a 0.2mm tip bucket.

...2 decimal places is what we normally use. 0.2mm could be rounded up to 0.01

Thanks for that info. If using just 2 decimal places is acceptable to display rainfall in inches, so that option it will be implemented on next software release.

[danner]

... Can any rain gauge actually measure 0.1mm of rain? I would think the bucket tip would require a lot more rain than 0.1mm.

I have referred 0.1mm just as a reference value, however there are some rain gauges that can measure 0.1mm of rain, and 0.2mm are common. The metric versions of the Davis rain gauges, all use a 0.2mm tip bucket.

...2 decimal places is what we normally use. 0.2mm could be rounded up to 0.01

Thanks for that info. If using just 2 decimal places is acceptable to display rainfall in inches, so that option it will be implemented on next software release.

Relatively speaking 0.2mm is twice as much as 0.1mm.   I've been using cheap chinese weather stations since about 2005, Davis was out of my price range, but nice to know their rain gauges are very good.

Thank you for adding imperial units for rain on the display. I would have to pull out my calculator to convert from those funny numbers to other funny numbers.

[werk_ag]

Thank you for adding imperial units for rain on the display. I would have to pull out my calculator to convert from those funny numbers to other funny numbers.

WeatherDuino Pro2 already allow showing all units in both Metric and Imperial system, except the rainfall. I don't know why I haven't did it before.  
I have spent the last hours implementing it, and it seems to be working well. Rainfall data in inches will be shown with two decimal places.

[danner]

Outstanding, thank you!

[danner]

Bugfix worked, thanks!

[danner]

I'm not sure if this is the correct place to request it, but could the internal web page "ATM" reading be changed use 2 decimal places when the user is using inHg? At the moment 29.97inHg is being rounded up to 30.0inHg. I know its a small nit.

TIA

[JT118]

... Is there no way to display inches?

// --------------------------------------------------------------------------------------
//   Define data display units
// --------------------------------------------------------------------------------------
#define Date_Time_Format 1     // 0 for dd-mm-yyyy, 1 for yyyy/mm/dd
byte Temp_Display_Unit = 1;    // 0 for ºC, 1 for ºF
byte ATM_Display_Unit  = 1;    // 0 for mBar, 1 for inHg
byte Rain_Display_Unit = 0;    // no setting, always mm
byte Wind_Display_Unit = 1;    // 0 for Km/h, 1 for mph, 2 for m/s, 3 for Knots

I know that commonly the rainfall in USA is expressed in inches. Unfortunately for USA users, the WeatherDuino can only display the rainfall (and rainfall rate) in mm. I don't remember where but there are a discussion on the forum about this matter. The main reason is about precision, to display 0.1mm of rain in inches, we need to use at least 4 decimal places.

2 decimal places is what we normally use. 0.2mm could be rounded up to 0.01". Can any rain gauge actually measure 0.1mm of rain? I would think the bucket tip would require a lot more rain than 0.1mm.

The 0.1mm refers to the depth of the rain falling, and not to the amount of water in the bucket, for example the standard FO gauge is 55cm2 cross sectional area, therefore 55x0.1=5.5ml in bucket. FO gauges, though rather vague, are in theory 0.3mm rain per tip therefore 16.5ml of water in bucket per tip. See here for expansion of this: http://www.meteocercal.info/forum/Thread...264?page=3

[AllyCat]

Hi,

Can any rain gauge actually measure 0.1mm of rain? I would think the bucket tip would require a lot more rain than 0.1mm.

As an experiment I mounted a 15 cm (6 inches) diameter funnel above the FO rain sensor to give a nominal 0.1 mm resolution.  I believe the normal definition of a wet/dry day is if => 0.2 mm of rain falls, so the 0.3 mm of the FO is not really "good enough".  Particularly as in my experience, it sometimes can be  prone to a single "false tip" when the morning sun strikes it, which might affect a "record" for the longest period of wet or dry days.

However, the funnel did not necessarily give any earlier warning of the onset of rain, because the water droplets tended to hang on the funnel sides, unless treated with a surface-tension-reduction coating such as "Rain-X".  Another potential issue is that a very high rate of rainfall may "overload" the see-saw (which "loses" some water whilst it is actually tipping), but "splash out" is a well-known issue with the basic FO rain sensor anyway.

For the first onset of rain the hydreon RG-11 is rather interesting with a discussion here.  It can emulate a tipping bucket with a resolution down to 0.0001" (0.1 mil) or even 0.001mm !  But I don't believe the absolute (overall total) accuracy is (or could be) as high as a well-maintained tipping bucket.  It also requires a local power supply so it is not suitable to use with most pure battery-operated sensor/transmitter systems, but this might not be a major issue for a Weatherduino-based station.

Cheers,   Alan.

[danner]

Thank you.