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SX1276/78 OTAA/downlink issue

Hello, this is NoriAbe from Japan.

Currently I have OTAA/downlink related problems on Dragino LoRa mini, equipped with
ATMega328P controller and SX1276/78 wireless chip. And my gateway is Multitech Conduit.
I’m using LMIC software libralies.

My problem is my endpoint can join OTAA session and send up link messages. But it can
NOT receive downlink messages. Actually sometimes it does, but sometimes it does NOT.
Its behavior is not stable, I think.

I found some items which may solve my problems in your FAQ lists. For example,

image

Could you give me more detailed information on how to check the frequency offset, the software/firmware settings on both sides?

Dragino guy did NOT know about it. Multitech guy said GW seemed to be OK. That’s it.

I need Semtech, an expart of communication device provider, know-how information.

Thank you,

Hi,

Please open an issue in your LMIC provider ticketing system as Semtech to not support LMIC.
Nevertheless if the LMIC flavor you use implements LMIC_setClockError(MAX_CLOCK_ERROR * 1 / 100); you can try to increase this value: it will set the open the RX windows wider, so it will compensate for the ATMega clock drift. More explanations on LMIC-Arduino repository.