No one has replied
Thank you for your reply.
Is there no open source in this case?
I use the following code: https://github.com/crami/RAK811_BreakBoard
Which I compile and upload under Linux.
It does not always happen, only sometimes.
For the manufacturer it's either ARM or ST, I'd choose ST because Rak811 seems to use a stm32l1xxx MCU from ST
@88bit Thank you. I was able to connect to GPS by enabling Serial interface using raspi-config utility and setting gps_port = 'ttyS0'.
Looks like your connection to RAK Support Center was lost, please wait while we try to reconnect.