ATMEGA3208 MegaCoreX- ttn-otaa - still joining

I tried today LMIC library and example ttn-otaa with TTNv3 and my custom pcb which consist of ATMEGA3208 and RFM95. I filled APPEUI, DEVEUI and APPKEY. But when it starts it still trying to join network and I see successful join in ttn console. Maybe some incompatibility with MegaCoreX ? Will be glad for any help.

In serial it repeatedly every few seconds writes:

Packet queued

Some other screenshots

Sorry; you’d think that since I run the site, I would have seen this and responded earlier… but I’m still trying to find an accommodation with Discourse’s notification system.


This is a clear example where everything is working in the uplink path, but something is broken in the downlink path. Most likely there’s an antenna switch that has to moved to the RX position by a GPIO; could also be a timing issue, or even a gateway issue. I always suggest the raw sketch as a diagnostic at this point, if you have two devices.