Table of Contents:

1.  Introduction

Notes for using Dragino Devices with TTN Stack3.

2.  Downlink

Use MQTT API for downlink: Reference: TTN Stack v3 MQTT reference

Download command is:

mosquitto_pub -h eu1.cloud.thethings.industries -p 1883 -t v3/akXXXXXps@XXXXXX/devices/lsn50/down/push -u akXXXXXps@XXXXXX -P NNSXS.XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX.LVQZECLX5FZ3XO5ACOW47IZ6HM54DMBBU776C53ZQHPLPQALIXYA -m '{"downlinks":[{"f_port": 2,"frm_payload":"AwAA","priority": "HIGH","confirmed": true}]}'

 

The MQTT command use -h,-p,-u,-P options. We can find them in the website.

 

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find -h : broker address , -p port and -u: user name

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find -P : Password

User MQTT.FX to simulate a downlink

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Use MQTT.FX to simulate downlink

Input connection info

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Input MQTT connection info

Send a downstream

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Gateway traffic for downstream

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Downstream data flow will like below:

image-20220526142741-8.png

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3.  Trouble Shooting

3.1  Problem when register a device to TTNv3 if it is already register to TTNv2

When you register the device in V2 and V3 with the same key and EUI, the device can only connect to V2.

image-20220526142914-10.png

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If you want the device to connect to V3. You must change your key and EUI, or delete the device registered on V2.

3.2  MIC Mismatch or MIC Failed

When the device is registered or the device is working normally, the problem of MIC mismatch and MIC failed occurs.

Under normal circumstances, users need to change the APPKEY to solve this problem.

 

image-20220526143057-12.png

MIC Mismatch