How to post a DeviceEUI to a IoT topic?

Question

I have several Wireless/LoRa devices with their own DeviceId and DevEui identifiers.  I have them routing their uplinks to a vanilla topic like `devices/lorawan/uplink`.

But I'd like them to post their uplinks on their own subtopic using their DevEui or DeviceId.

e.g. `devices/lorawan/ab123fffe4567890/uplinks`

I assume this is done using a Wireless destination, but it's not clear what the variable is when configuring the topic inside the destination settings.  Something like`devices/lorawan/${WirelessMetadata.DevEui}/uplinks`?

Accepted Answer

Hi,

my proposed approach is to follow these steps:

1. Point a Wireless Destination to an AWS IoT Rule (let's call it ProcessLoRaWANUplink)
2. Use the following IoT SQL:
```
SELECT *
```
3. Add "Republish" action and specify a topic as following:
```
 devices/lorawan/${WirelessMetadata.LoRaWAN.DevEui}/uplinks
```

Please notice:

- You should double-check that including metadata is enabled in the Service Profile you assigned to the LoRaWAN device  
-  Double-Check that IAM Role assigned to the "Republish" action us allowing "iot:Publish" to  "devices/lorawan/*".  In this specific case, I recommend not to use "Create role" option when creating an Action the Management Console, but create a role  using AWS IAM Management Console, using the following trust relationship:
```
{
  "Version": "2012-10-17",
  "Statement": [
    {
      "Effect": "Allow",
      "Principal": {
        "Service": "iot.amazonaws.com"
      },
      "Action": "sts:AssumeRole"
    }
  ]
}
```

and the following policy:
```
{
    "Version": "2012-10-17",
    "Statement": {
        "Effect": "Allow",
        "Action": "iot:Publish",
        "Resource": "arn:aws:iot:::topic/devices/lorawan/*"
    }
}
```

best regards, Andrei

How to post a DeviceEUI to a IoT topic?

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