Join-accept sent but not recieved. Wrong timing?

ChirpStack (v4) Setup and configuration
1

Hello.
For three days I’ve been trying to get otaa lorawan to work with a Mikrotik wAP lr8 gateway and LILYGO T-Beam v 1.2, but I am getting the same problem over and over. I’ve tried multiple diffrent loraWan libraies on the t-beam.

The code I am running on the t-beam is taken from this example: GitHub - designer2k2/tbeam-lorawan-mapper: LoRaWan GPS Mapper for TTN and Helium Network, using the TBeam1.2 SX1262
The example uses the exact same hardware as I am, so it should work correct.

The problem I am facing is that the t-beam is not recieving the join-accept.
In the mikrotik traffic console I can see both the join request and also the join accept.

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Same for the Chirpstack. I can see both the request and the accept.

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Screenshot 2025-02-05 131228
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As you can see in the picture of the mikrotik console above, the join-accept is sent the same second as the join-request. Shouldn’t there be a 5 seconds delay? Is there a setting in chirpstack for that?
My theory is that the join-accept timing is wrong. And that the t-beam isn’t lilstning for the accept when the accept is sent.

If I can provide any more information that might make it easier for anybody to help me just let me know.
Thanks in advance for any help.

2

I guess that “Time” isn’t the time of transmission. To transmit a message via RX1 or RX2, the downlink request is sent to the gateway and is programmed for transmission. Transmission is made at a specific time (according to the gateway’s internal clock), and is not done when the request is received.

On the other hand, the gateway transmits immediately for Class C-styled downlinks, which is not applicable to the join procedure.

3

I’d also assume timing is not the issue here. Are you certain all of your device ↔ server frequencies match? Are you using eu868? As that is the frequency of the join-accept.

If it’s not that, maybe it’s a misconfiguration of the device profile.

4

Please try running RadioLib’s LoRaWAN examples first as a stand-alone sketch. That way you can confirm that the fundamentals of the mapper sketch work (as it uses RadioLib at its core).

5

Thanks for the replies :slight_smile: I just order a usb to lora dongle to hopefully help me debug it even more.
@Liam_Philipp I am very sure, but will dubbelcheck.
As @bns said I will create a stand-alone, just fundamentals sketch to eliminate all other variables.
Will get back in a few days when I’ve got time to test it :slight_smile: