I'm trying to understand how ATSAMD21G18A communicates with Murata LoRa-module.
I assume with SPI bus on PA12_MOSI_TX, PA15_MISO_RX and PA13_SCK.
With scope I can see traffic on PA12_MOSI_TX and on PA15_MISO_RX but NO clock signal on PA13_SCK. And I can not see PA14_RF_SSN pulled down during the communication.
How that could be possible that no clock signal? How do they communicate?
I have checked with MKR WAN 1300 board and with MKR WAN 1310 board and same thing. I'm testing with Arduino MKR example sketch FirstConfiguration.ino.