No InfluxDB entry for Number result from EXEC binding

Add-ons Persistence Services
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1

Hi.
I just got a REHAU airquality sensor I put into my Raspberry Pi. Together with a small tool (“airsensor”) that reads the values from the sensor and put them to STDOUT, I hope to have a cheap monitoring for my Homeoffice (which I have to use quite regularly currently, thanks to COVID-19).
On command line it works quite well, “/home/openhabian/rehau/airsensor -o -v” returns just the value I need:

openhabian@openhab:~ $ /home/openhabian/rehau/airsensor -o -v
1226

The resulting item I defined is:

Number:Dimensionless AirSensor_Output  "Rückgabewert Luftgüte"  (gAirSensor) {channel="exec:command:airsensor:output"}

I then configured a Thing with this command, REGEX transformation (which should not be used here) and 60 second interval. In influxdb.persist I added a line to “Item”:

AirSensor_Output     : strategy = everyChange, everyHour, everyMinute

The problem I face: I don’t get any value into my InfluxDB. When I change the datatype for the item to String, these are imported into the DB, but of course it’s not possible to create a grafana graph for it :frowning:

Could someone point out what’s wrong?

2

Exec binding output channel is of String type. That’s it, there is no Number type channel.

Unfortunately there are as yet no profile types available to match a String channel to a Number Item.

Your recourse is to output to a String Item, and have a rule triggered on update parse the string to a number and post to a Number Item.

3

Ah okay, thanks for the confirmation. I didn’t get an error, but this explains a lot :slight_smile:
I will do as proposed then …