OTAA only on first Join, then ABP on LMiC


(Robert Keck) #1

Good morning everyone,
I have a question regarding the LMiC Library and the differences between OTAA and ABP.
I am currently developing a Low Power device using a stm32 and LMiC. To achieve the lowest power consumption,
I plan to use the lowest sleep mode the stm32 can get into, where the controller is almost turned off (so no data is persisted).
Because I only want to have to Join a single time over OTAA (when the device is turned on the very first time (or after a custom reset)) I am writing the network session and the application router key to the flash and use them the next time with ABP before sending my payload. Only problem is, that this doesn’t work. The sendjob times out every time I try to send via ABP using the params I got from the 1st OTAA join.
Has anyone an idea or done it before?

Thanks in advance,
Rob


(Alexbn71) #2

Hi Rob, with which LoRaWAN module?

Alex


(Robert Keck) #3

I built a custom board with sx1272.
OTAA works perfectly fine, but when i want to start a ABP Session with the params stored in the flash it doesn’t work. Is there anything more i have to call besides LMIC_setSession(id, addr, netkey, appkey) to make it work?
Direct ABP (without doing an OTAA before) doesn’t work either, I just found out.