Outgoing Value Format on MQTT thing?

Add-ons Bindings
1

Running OpenHab 2.5.8. Regarding this setting on an MQTT thing…

Outgoing Value Format

Format a value before it is published to the MQTT broker. The default is to just pass the channel/item state. If you want to apply a prefix, say "MYCOLOR,", you would use "MYCOLOR,%s". If you want to adjust the precision of a number to for example 4 digits, you would use "%.4f".

I have a WiFi ESP chip that I’ve programmed up to turn on various blinds around the house. It will receive for example “HALLOPEN” to a “openhab/blinds/trigger” topic that causes the ESP chip to then switch a MOSFET sending a logical key press to an infrared remote therefore opening the hall blinds. Another example would be send “BEDROOMSCLOSE” to close the bedroom blinds via a different IR remote.

I figured based on the description above, on my Hallway blinds thing for example, I could put “HALL,%s” in the “Outgoing Value Format” box above, in the hope that the thing would prefix the “CLOSE” command on a rollershutter item type that is sent with “HALL” therefore sending “HALLCLOSE” but this does not work.

Am I reading the text of what this setting is supposed to do incorrectly? If so what is the easiest way to achieve this?

2

Argh… NVM… seems no pattern to transform the output is supported on a rollershutter. Bottom of this page :frowning: Any other simple solution to this?

3

You could use a rule to publish data to MQTT

4

Thanks, yeah I thought about using rules but figured with advancements in the mqtt binding with pattern transformations etc it should be doable in the paperui

5

You can use a transformation. A simple MAP transformation might be sufficient. If not a JavaScript transformation can do pretty much anything.

6

I though that meant only that the default is %s, without frills. The openHAB command is passed unaltered to MQTT payload.
I’d expect “HALL,%s” to produce a payload like HALL,down or HALL,56

But you can’t get from openHAB command DOWN to payload text CLOSE by formatting alone, so some transformation will be needed.