What LMIC state must be preserved during sleep mode?

[arjanvanb (Arjan)]

As an aside, I once noticed the following:

@arjanvanb

When a counter increments, it seems LMiC allows for storing it in some “device database” (beware: my own terminology). Like for LoRaWAN’s FCntUp :

LMIC.seqnoUp += 1;
DO_DEVDB(LMIC.seqnoUp,seqnoUp);

The same macro is used after Over-the-Air Activation, or for adaptive date rate. However, DO_DEVDB is a no-operation in oslmic.h :

#define DO_DEVDB(field1,field2) /**/

(Which, I think, is also why this code even compiles, as the bare seqnoUp is not even defined?)

But maybe my guess about the meaning of the DO_DEVDB macro is wrong. First, for a database, I’d have expected LMiC to define that in the HAL, not in oslmic.h . Also, I don’t see how the values are ever read back from such database, in the IBM code.