Encrypted payload and empty JSON object (EM300-TH)

ChirpStack Application Server
#1

I’ve connected EM300-TH sensor to Chirpstack server and everything works correctly but I receive wrong/encrypted payload data.
I tried Cayenne LPP codec and this custom codec which was recommended in Milesight EM300-TH manual, but none of these works - both returns an empty JSON object and payload data is not correct.
For example I receive
IK5rA/8iJQ==
which in hex is
20 ae 6b 03 ff 22 25
but from EM300-TH manual I should receive something like this:
em300th0
As I have looked, the first two bytes have never been 01-06.

I’ve tried “json” and “json_v3” payload marshalers.

My question is how exactly the payload is encrypted and maybe an advice how to decrypt EM300-TH data? Or maybe there is a way to not encrypt payload at all?

In addition, I have tried Milesight IoT Cloud and there payload data was in correct form, so the device works correctly.

Thanks

#2

It started working when I changed marshaler to “protobuf” with custom Milesight decoder.

#3

Nevermind, changing lorawan version from 1.1.1 to 1.0.2 made it work. Even for the uc1114 which has version 1.1.1 in the specs. It works with both json and protobuf marshaler