How to strip out unwanted MQTT inputs(?)

[haskle]

Newbie(ish) question: I have managed to set up my Node_RED RPi to receive MQTT messages with the topic home/rtl_433 from an MQTT broker installed on a different RPi.

But there are a load of messages that I am not interested in, and I don't know how to "filter them out" or delete / remove them.

EG: I do not want these messages ...

home/rtl_433 : msg.payload : Object
object
time: "2021-01-26 17:29:25"
brand: "OS"
model: "Oregon-v1"
id: 0
channel: 4
battery_ok: 0
temperature_C: -157.7
mic: "CHECKSUM"

... but I do want these ...

home/rtl_433 : msg.payload : Object
object
time: "2021-01-26 17:29:16"
model: "Oil-SonicSmart"
id: 136628653
flags: 128
maybetemp: 24
temperature_C: 8.333
binding_countdown: 0
depth_cm: 96

How might I achieve this?

Many thanks!

[E1cid]

if you had given your mqtt topics another value eg

home/device1/rtl_433

You could target the topic to the device. To get all devices you could then use wildcard e.g. home/+/rtl_433

As you have not, you can use a switch node to only allow message to pass on certain message property value, etc.

[Colin]

You can use a Switch node to only pass messages where msg.payload.model is Oil-SonicSmart.