Cumulus Support

Hello!

I was looking at my new Davis Vantage Pro2 console the other day and I suddenly realised that the barometer is shown as 1 decimal point on the console but Cumulus MX shows this as 2 decimal points. Does anyone know why the console only shows this as 1 and not 2 decimal points?

I was thinking if there was a way to change the barometer to 1 decimal point on Cumulus MX but then I'd loose accuracy.

Thanks,

William

The console uses 2dp for inHg which is sensible, and 1dp for hPa/mb which is also sensible. The data protocol uses 2dp so it can send inHg or hPa, but the hPa values are converted from inHg 2dp values, so not every second decimal place is not even available when using hPa, you will find it jumps between the available values.

Cumulus doesn't have any mechanism for convert Davis hPa values to 1dp, but I do myself and only display everything to 1dp on my website. Quoting hPa to 2dp is a nonsense, it equates to an elevation change of around 10 cm at sea level. If anyone can calibrate their barometer to that level of precision I'll buy them a beer! Plus the Davis applies a 'correction' to the readings to attempt to compensate for temperature and humidity variations.

Ok, thanks Mark.

How did you manage to get everything to measure in 1 decimal point?

mcrossley wrote:Quoting hPa to 2dp is a nonsense, it equates to an elevation change of around 10 cm at sea level.

Just walking round the room the console is in will affect the readings at 2dp precision, so noise will drown any true atmospheric signal!

I increased the number of decimal places for Davis stations in Cumulus on the advice of Davis (to 2 for hPa/mb and 3 for inHg). Make of that what you will.

Eventually MX will allow the user complete control of the number of decimal places displayed and logged for each sensor, then people can do exactly as they like, in either direction.

I'll add an ini-file switch to the next build of MX to turn off the increased pressure DPs for Davis stations.

You're just amazing, Steve. You solve everything, thanks very much.