Hi there,
I'm having a lot of fun with running apps on nrf9160 SiP on board of nrf9160 DK.
nrf52840 SoC contains the standard board controller fw.
nrf9160 SiP contains the standard secure bootloader from samples and modem fw.
My app is very simple and uses only leds.
What I'm trying to do is just to blink by LED1 each 100 msec. Only Zephyr's main thread is being used.
The probability of a successful run when i see a blinking led is about 20-30% of all tries.
I've tried several DK start sequences and none of them give me a 100% success rate:
* switch DK off / on and wait
* switch DK off / on, push reset button (nrf91 debug state) and wait
* switch DK off / on, set nrf52 debug, push reset button and wait
* switch DK off / on, set nrf52 debug, push reset button, set nrf91 debug, push reset button and wait
3 sec delay has been added to the very beginning of the main thread to give time for the board controller to boot and init all routes.
In all successful runs it takes about 10-30 seconds to start blinking.
What's the proper start sequence for nrf9160 DK?