LPS8v2 failed command down

Gateways
1

I am using a Dragino LPS8v2 gateway with a LT22222-IO end device and communicating with the onboard node-red server. I can receive DataUp fine but never complete a command/down. If I manually place the data into Enqueue it works fine. Is there a way to interrupt and see the command/down packet?
{
devEui: “a840417618xxxxxx”
confirmed: false
fport: 10
data: “AwER”
}

Any direction would be greatly appreciated

2

What MQTT topic are you posting them to?

Should be:

application/<APPLICATION_ID>/device/<DEV_EUI>/command/down

If you want to see the downlinks sent from Chirpstack to the gateway you can subscribe to the topic: <region>/gateway/<gateway_id>/command/down although these will be encrypted.

3

Here is the topic:
application/212e403b-1af2-4489-aa5a-62190303ccbb/device/a8404142f18941b6/command/down

And the data:
const datastr = msg.payload
const payloadobj = {
“devEui”: “a84041761859fa76”,
“confirmed”: false,
“fport”: 10,
“data”: datastr
}

4

I think you’ve run into a classic coding error here. The case of the missing capitol!

If you look at the example:

{
    "devEui": "0102030405060708",             // this must match the DEV_EUI of the MQTT topic
    "confirmed": true,                        // whether the payload must be sent as confirmed data down or not
    "fPort": 10,                              // FPort to use (must be > 0)
    "data": "...."                            // base64 encoded data (plaintext, will be encrypted by ChirpStack)
    "object": {                               // decoded object (when application coded has been configured)
        "temperatureSensor": {"1": 25},       // when providing the 'object', you can omit 'data'
        "humiditySensor": {"1": 32}
    }
}

fPort has a capitol P :wink:

1 Like
5

Downlink command from ChirpStack to LPS8v2 to LT-22222-L surely works.

You need to change the decode for the downlink to control LT-22222-L.
https://iotthinks.com/wp-content/uploads/2022/11/LT-22222-L-Codec.txt