Downlinks using MQTT

Hi. I am having a lot of trouble sending a downlink from the app-server to a node using MQTT publish: mosquitto_pub -t application/1/device/a1a1b2b2c3c3d4d4 -f mqtt.json

the mqtt.json looks like this:
{
“confirmed”: false,
“fPort”: 5,
“data”: “SGVsbG8=”,
“object”: {
“temperatureSensor”: {“1”: 25},
“humiditySensor”: {“1”: 32}
}

I inserted the following line into the lora-app-server.toml under [application_server.integration.mqtt]:
downlink_topic_template=“application/1/device/a1a1b2b2c3c3d4d4/tx”

from what i read of the documentation, this is all i need to do.

I see the following screenshot in the Loraserver log files.

I am running Loraserver using docker installed last week with no configuration changes, except for the frequency band (AU_915_928), and the lora-app-server.toml. This is on an Ubuntu 18.04.2

I have searched for the error and found no useful information.
Any help on this error would be very much appreciated. Thanks

You should not modify the downlink_topic_template in config file, it is a template, not your real mqtt topic.

1 Like

I see. i think i misunderstood the instructions for the app server config MQTT setup. Okay i made that change and have a new error to deal with: a problem with the payload i sending in the file?

appserver_1 | time=“2019-05-09T07:36:34Z” level=error msg="integration/mqtt: tx payload unmarshal error: unexpected EOF

Please see https://forum.loraserver.io/t/problem-with-sending-downlink-via-mqtt/4263.