[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