Question: Use ADR with deep sleep (ESP32)

[Schrolli91]

Hello folks,

i am using an ESP32 on a TTGO T-Beam Board.
Is it possible to use the ADR functionality (LMIC_setAdrMode(true)) with the ESP32 deep sleep?

Which values from the LMIC struct i have to safe to the power down resistent RTC ram and restore after wake up (it's a real controller reset here)?
Are all needed params in this struct available?

I use the ABP activation mode and at the moment i'm only safe and restore the up- and downlink sequence counters (seqnoDn and seqnoUp) after the LMIC_setSession() call as mentioned in the pdf documentation.

Is the adrAckReq enough? Or are some other fields needed?
What exactly is the adrTxPow and adrChanged?

Regards,
Basti

[zsellera]

Save&restore both adrAckReq and adrTxPow; adrTxPow is the actual tx power limit set by the network, adrChanged is a flag to reset the adr counter (no need to save it).

[terrillmoore]

Please look at mcci-catena/arduino-lorawan#150 which adds full support for saving/restoring the LMIC state. I've tested it with US915. If I get a chance to fix channel shuffling, it will need one more thing (the channel-shuffle state) to be complete. But it's a decent (C++) reference for saving/restoring state.