Fetching min/max values for weather sensors

[norrland]

It would have been great if there was a way to fetch at least daily min/max values for weather sensors like temperature, wind, barometric pressure and humidity through the API. Even better if we could fetch daily, weekly, monthly and yearly min/max values. It is an important feature when using Domoticz as a weather station.

Using a request like this returns current values
/json.htm?type=devices&rid=99

The history request returns all values for a period
/json.htm?type=graph&sensor=temp&idx=99&range=day

For both cases it is up the the front-end or other caller to calculate min/max. Or is there another option that I've not been able to find?

Right now, I'm using virtual sensors that are set by a LUA script that invokes a bash-script that uses SQL to fetch max/min values in the Domoticz DB. A somewhat lengthy solution.

[stlaha2007]

Sorry, but have you looked further at the json-wiki??

Month and Year reports include min-avg-max temp.
Try the following /json.htm?type=graph&sensor=temp&idx=IDX&range=month

Add it to your domoticz url and replace IDX with the temp-device you want...
Still need to seperate them.

[Edit: typo in sentence]

[norrland]

Thanks for your fast reply!

Yes, i understand that the monthly and yearly range gives min (tm), max (te) and average (ta) for days included. It is however only daily values. To get weekly or monthly you still need to calc, right?

If this is the json-wiki you are referring to, then yes, I've read it.
https://www.domoticz.com/wiki/Domoticz_API/JSON_URL's

As far as I can see it does not mention anything about min/max but it is not so hard to figure out with some testing. Or is there another wiki-page I've missed?

[mvzut]

I'm also interested in a more convenient way to fetch min/max values of temperature sensors. In other home automation systems it's often a built-in function. Maybe an idea to show this in the UI for each sensor, and report the values in the JSON output (or even in the otherdevices_svalues)?

By the way, you don't have to go via bash scripting to fetch daily min/max values, you can simply run a LUA script every minute that directly updates a virtual Domoticz device. I did it like this:

Code: Select all

min_max_buiten = otherdevices['Min/max buiten']
min_buiten = tonumber(string.match(min_max_buiten,'(.*)\194\176C /')) or 0
max_buiten = tonumber(string.match(min_max_buiten,'/ (.*)\194\176C')) or 0
temp_buiten = tonumber(otherdevices_svalues['Buiten achter']:match("([^;]+)"))
if temp_buiten > max_buiten then max_buiten = temp_buiten end
if temp_buiten < min_buiten then min_buiten = temp_buiten end
new_min_max_buiten = min_buiten .. '\194\176C / ' .. max_buiten..'\194\176C'
if new_min_max_buiten ~= min_max_buiten then
  table.insert(commandArray, {['UpdateDevice'] = otherdevices_idx['Min/max buiten'] .. '|0|' .. new_min_max_buiten})
end

You could also store the min/max values in individual dummy temperature devices, but I solved it with a text device.
Downside of this solution is that I have to do this for every temperature sensor that I want to know min/max values for. This creates a lot of overhead and extra devices.

[stlaha2007]

Both are correct conclusions or solutions.

I agree there's no weekly graph for temp, and also not a min/max on de daily.
A weekly graph incl. min/max might be handy.
Also the less quick methode is temp tab button custom graph with long term gives you more to your liking.

Just curious... why do you guys want min/max of the current day/24hours? As i can see it directly (not by .05 exactly ) ehat min and max are.

[Nautilus]

I'm also interested in a more convenient way to fetch min/max values of temperature sensors. In other home automation systems it's often a built-in function. Maybe an idea to show this in the UI for each sensor, and report the values in the JSON output (or even in the otherdevices_svalues)?

By the way, you don't have to go via bash scripting to fetch daily min/max values, you can simply run a LUA script every minute that directly updates a virtual Domoticz device. I did it like this:

You could also store the min/max values in individual dummy temperature devices, but I solved it with a text device.
Downside of this solution is that I have to do this for every temperature sensor that I want to know min/max values for. This creates a lot of overhead and extra devices.

Can I ask how do you manage the time period of the min / max temps with this approach, do you just clear the values at some point or? Otherwise, if there is one really warm or cold day, then the values basically never update after that? Or have I missed something?

[mvzut]

I'm also interested in a more convenient way to fetch min/max values of temperature sensors. In other home automation systems it's often a built-in function. Maybe an idea to show this in the UI for each sensor, and report the values in the JSON output (or even in the otherdevices_svalues)?

By the way, you don't have to go via bash scripting to fetch daily min/max values, you can simply run a LUA script every minute that directly updates a virtual Domoticz device. I did it like this:

You could also store the min/max values in individual dummy temperature devices, but I solved it with a text device.
Downside of this solution is that I have to do this for every temperature sensor that I want to know min/max values for. This creates a lot of overhead and extra devices.

Can I ask how do you manage the time period of the mio / max temps with this approach? If there is one really warm or cold day, then the values basically never update after that? Or have I missed something?

Sorry, I forgot to mention that I set both values (min and max) to the current values at midnight.

[Nautilus]

Sorry, I forgot to mention that I set both values (min and max) to the current values at midnight.

Ok, I assumed something like that Would be nice to have e..g. a rolling 24h min / max but this is probably the simplest way to get started.

[Toulon7559]

Perhaps a very 'practical & down to earth' reaction, but why don't you apply a website like WeatherUnderground to make the info on min/max per time-period? They already have the database- and calculation-functions to produce the answers to your question, as well as a presentation of results.
If WUnderground is not your favourite, then as alternative AWEKAS or PWSWeather can do the job.

And if you want to keep the job at your computer, perhaps PYWWS is your friend (although it needs 'some' effort to get it running).

[norrland]

Perhaps a very 'practical & down to earth' reaction, but why don't you apply a website like WeatherUnderground to make the info on min/max per time-period? They already have the database- and calculation-functions to produce the answers to your question, as well as a presentation of results.
If WUnderground is not your favourite, then as alternative AWEKAS or PWSWeather can do the job.

And if you want to keep the job at your computer, perhaps PYWWS is your friend (although it needs 'some' effort to get it running).

That's how I'm doing today, with a local http://www.wviewweather.com server. It is however not so smooth to have two different sites and having to flip pages on both of them to get a complete overview of both weather, cameras and automation.

Another solution would be to build a new dashboard/frontpage that can incorporate all servers state but it would take more effort than I'm able to put into it. Domoticz is so close to fix all these features, especially with the new front pages and themes available here on the forum.

This small change would get us a bit closer!