Page 1 of 1

Python script emulating vantage protocol

Posted: Thu 12 Jan 2017 8:44 pm
by engolling
Hello,

I want to write a python script beeing able to send data from my self built prototype weather station to cumulus (picture in attachment).
I am measuring the following data:
  1. Temperature 2m
  2. Temperature 2m in the Sun
  3. 7 Temperatures from 1m to -1m over/under ground
  4. Pressure
  5. Humidity
  6. Wind speed
  7. Wind direction
  8. UV radiation
  9. global radiation
  10. Illuminance
  11. Percipation
  12. Snow depth
  13. Leaf wetness
  14. Particle concentration
If someone is interested in, I can post more details of the station, if I find some time.

Since the Vantage protocol is well documented I consider to implement this. After reading the documentation I saw that the LOOP packet is able to transmit data of more extra sensors then the LOOP2 packet. Is that right?

Has anyone a idea if there is a more apropriate and well documented protocol especially I have a lot of possible data to transmit.

When implementing the LOOP packet, can anyone tell me which data is not taken into account by cumulus like the alarms or the forecast icons.
I assume there is no need to implement the HILOW packed, because cumulus calculates all the data by itself.
When the script is working, I will provide it here, maybe someone can use it, too.

Hoping for a lot of feedback.

Stefan

Re: Python script emulating vantage protocol

Posted: Thu 12 Jan 2017 9:02 pm
by steve
I can't tell you exactly which items from the LOOP packet that Cumulus 1 uses, because it doesn't handle the LOOP packets itself, the Davis DLL does it.

I could tell you exactly what items from the LOOP packet Cumulus MX uses, but I would have to extract the information into a form that I could give to you, and that is somewhat time consuming, and complicated by the fact that it extracts some values from the packets that it doesn't currently use; I would have to check each one to see if it actually uses it.

You're right that Cumulus (1 and MX) doesn't use the high/low data or anything else other than LOOP packets and archive packets. It should be reasonably obvious which items from those packets it uses given the data that it makes available. It uses the annual rain total as the increasing counter from which it calculates all the other rain totals.

Re: Python script emulating vantage protocol

Posted: Fri 13 Jan 2017 9:18 am
by prodata
Remember that in addition to populating the LOOP/LOOP2 packets, any emulator software also presumably needs to emulate the API by which data packets are normally requested from the WL logger. This isn't necessarily difficult but would be essential if any analysis software is going to think that your emulator is a logger.

LOOP caters for all the sensors that can be attached to a wireless VP2 station. LOOP2 only services a subset of those sensors but does include more derived values such as 2min wind speed and several other analogous values that are normally calculated by the VP2 console from the raw sensor readings. Conversely, LOOP2 does not include any readings from supplementary sensors, eg 6345 transmitters.

Re: Python script emulating vantage protocol

Posted: Fri 13 Jan 2017 10:18 am
by laulau
Hi,
This project is compatible with Cumulus by emulating a Davis VP :

https://cumulus.hosiene.co.uk/viewtopic.php?f=16&t=12083

Re: Python script emulating vantage protocol

Posted: Sat 14 Jan 2017 8:40 am
by engolling
Hello,

thank you for all your replys.

@steve It's no problem, if it's very time consuming because I can write default data in fields that I do not use. Just thought maybe there is some overview I did not find.

I have already seen the weather duino project but I could not download the software without registration, but I will have a look at it.

I will keep you updated if there are news.

Re: Python script emulating vantage protocol

Posted: Sat 14 Jan 2017 1:34 pm
by ConligWX
Not sure if this is of any use.

Have you tried looking at http://www.weewx.com/. the weather station software is written python.

Re: Python script emulating vantage protocol

Posted: Sun 12 Feb 2017 10:08 pm
by engolling
After a lot of considerations a skipped programming the python script and I'm going to implement the emulation into the arduino µC like the WeatherDuino project does.
Thank you for all your feedback.