Accessing Vantage Pro2 directly from LInux (Rasberry)

[cirdan52]

This may be a dumb question but for those using CumulusMX on a linux machine/Rasberry Pi is there a way for example to set the barometer without unhooking the logger and hooking it up to a Windows machine and running Weatherlink?

[steve]

I've never had to set the barometer on mine, so I don't know what it involves. Perhaps it can be done from the console?

Edit: is it this?

Calibrating Barometric Pressure
Before calibrating the barometric pressure, be sure the station is set to the correct elevation.
See “Screen 10: Elevation” on page 14 for more information.
1. Press BAR to select barometric pressure.
2. Press and release 2ND, then press and hold SET.
The pressure variable blinks.
3. Continue holding the key until the ticker reads “set barometer . . . ”.
4. Press the < and > keys to select digits in the variable.
5. Press + and - keys to add to or subtract from the digit’s value.
6. Press DONE to exit calibration.

[cirdan52]

I've never had to set the barometer on mine, so I don't know what it involves. Perhaps it can be done from the console?

Edit: is it this?

Calibrating Barometric Pressure
Before calibrating the barometric pressure, be sure the station is set to the correct elevation.
See “Screen 10: Elevation” on page 14 for more information.
1. Press BAR to select barometric pressure.
2. Press and release 2ND, then press and hold SET.
The pressure variable blinks.
3. Continue holding the key until the ticker reads “set barometer . . . ”.
4. Press the < and > keys to select digits in the variable.
5. Press + and - keys to add to or subtract from the digit’s value.
6. Press DONE to exit calibration.

That's true if you are using the console but not an option if your just using the Envoy. The jist of my question is barometer drift and resetting my barometer to a ASOS/metar station to keep it in line for the area

[steve]

You could use a terminal program and send the command, it's not complicated. From the serial spec:

"BAR=<bar value to display (in Hg * 1000)-decimal> <elevation (ft)-decimal>"

If accepted, the console will respond with an "OK", otherwise it will respond with a Not Acknowledged (0x21 = "!") character.

Example (No local Barometer value, elevation 132 ft):
>"BAR=0 132"<LF>
<<LF><CR>"OK"<LF><CR>

Example (Barometer value = 29.491 in Hg, elevation 0 ft):
>"BAR=29491 0"<LF>
<<LF><CR>"OK"<LF><CR>

[acatalano]

Steve

I'm coming over to this post which you suggested, from the other regarding correcting the Barometric pressure in the Envoy. I'm having trouble understanding your suggestion to correct the Envoy. Is a terminal program used to send the correction factor to the Envoy which will then use it to process the Barometric pressure data, storing the correction factor in non-volatile RAM? I've looked thru the Envoy manual and don't see anything there.

[steve]

Yes - just as with a VP2 display console, you need to give the Envoy your altitude so that it can calculate sea-level pressure correctly. Cumulus cannot currently do this (set the altitude). If I were to write the code to do this at some point, it is likely that it would be in a separate utility - I have already started on a utility to set the logger interval. I don't know when I will find the time to continue with the utility.

[acatalano]

Steve
I have looked thru the Davis Weather Envoy manual and I do not see any instructions to programming altitude. Is there any documentation you could refer to me that gives an explanation? Setting the altitude is probably one of several settings that can be set in the Envoy so in general it would be useful to have this documentation. I'll call Davis today to see if they can provide this.

I have the Weatherlink software. Can they Envoy be programmed from there?

[cirdan52]

[quote="acatalano"]Steve
I have looked thru the Davis Weather Envoy manual and I do not see any instructions to programming altitude. Is there any documentation you could refer to me that gives an explanation? Setting the altitude is probably one of several settings that can be set in the Envoy so in general it would be useful to have this documentation. I'll call Davis today to see if they can provide this.

I have the Weatherlink software. Can they Envoy be programmed from there?[/quote

If you are using Weatherlink, you can set all the Envoy parameters in the program. My initial question to Steve was not using Weatherlink how would one set the Envoy which he explained using a terminal program. This gets around using Windows