Hi.

In our port of LoRaMAC some functions like OnMacStateCheckTimerEvent are running in ISR context due to timer callback. It seems the original implementation does the same. If this is correct, an ISR flags based solution might be better.

When we try Over The Air Activation with Atmel SAMR21-xpro, it crashes due to ISR stack overflow. This doesn't happen with STM32L1 based MCUs.

Cheers