Send a downlink message to the end node via RPI MQTT Broker not TTN odre other LORA SERVER

End Devices (Nodes)
1

Hello everyone,

My application on TTN is working fine, I can send uplink and downlink with my Dragino LG308 gateway to my LS01 and LHT65 end nodes.

But now I have built my MQTT Broker server on Raspberry Pi and my end node can send the uplink into my Raspberry Broker very well.

My problem is that I can’t send a downlink to my end node.

What data format should I use to send a downlink to my end node?

I’m not using TTN and instead I’m using a MQTT broker on the RPi. I have sent the “0xA601” function to it encoded as base64 but I get no response from the LG308 . In the LG308 log I get INFO~ [DNLK]Format error: when i try to sent some payload like pgE=

The topic on the LG308 that its subscribed to is also CLIENTID/# would this be correct?
the LG308 does appear to be receiving the instruction from mqtt but will not broadcast to LORA radios.

Any help is much appreciated,

thanks

2

Then maybe you should use the support channel for the software you are using. This forum is for TTN.

3

thank you for replay

i´m using mosquitto broker that i install on my Raspberry pi.

the question I would like to know is what payload format to use to send a downlink to my node with my MQTT Broker on RPI3.

4

Is your mqtt broker talking to TTN?

5

nop I configure the Gateway with my own Server IP Adresse from company.

gateway

6

If you are not using TTN the question is not for this forum. This forum is about TTN. Not other LoRaWAN solutions that are proprietary.

7

Hello kersing,

I user TTN MQTT broker and sending base64 coded json message. In TTN livedata I receive the coded message, but I’n not able to make a decoder for my Payload.
I’m searching everywhere but found nothing.

I would be happy, if you can help me.

Thx in advance.
Werner

8

What is sending the message and where do you want to use it? Where should the decoder be running?

9

Thx for Reply.
I publish with an ESP8266 via SMQTT to the TTN Broker this message:
{“downlinks”: [{“f_port”: 1,“frm_payload”: “6piB”,“priority”: “NORMAL”}]}, where 6piB is the base64 coded message A601 to this topic v3/myapplication/devices/eui-aaaaaaaaaaaaaaaa/down/push

In the livedata I see following
image

I have no idea to write the download Decoder in the TTN Console for this device and find nothing helpful in the web.

would be great, if you can help me.

10

You don’t need a downlink decoder. It is just a convenience function providing a human readable version of the downlink. Not having a downlink decoder doesn’t mean the downlink isn’t sent to the device.
I’ve never used a downlink decoder in 8 years working with TTN and my downlinks get to the end devices without any issues.

Did you find the help pages the console links to? If not, start at Payload Formatters | The Things Stack for LoRaWAN

To get rid of the error, make sure you set the decoder to “none”.

11

Hello Kersing,

thank you so much for your reply. First I changed the device downlink formatter to none, but still get the same Bytes in the TTN-Console.
Today I checked the base64 Code and coded it again at Base64 to hex: Encode and decode bytes online - cryptii and got a different Code.
After recompiling my ESP8266 and sending it, I got the right Bytes in the TTN-Console and with next received packet it resets the counter.

Have an nice weekend.

Werner