soldering SMD part is much easier than soldering to SMD parts.
After a half of night shoring MK22 pins I've managed to gather communication with C6000 when sending and receiving text messages (original 2.1.6 FW).
I've only collected SPI0 data, as there was no communication via SPI1. Also when I've tried to sniff interrupts I failed, as the parasite capacity induced by probe wires was too large for radio to work reliably.
I'm attaching two dumps:
- SMS_TXOK_RXOK.sr:
SMS from SQ6SFO(2606178) to APRS(262993) with content "ECHO".
After few second answer comes with standard "Hi Jakub, SMS was received(...)" - SMS_TXOK_RXOK.sr:
Same message, but as the hotspot was not receiving there were no confirmation SMS was sent succesfully.
Files can be opened by https://sigrok.org/wiki/PulseView
I'll try to decode the communication to easier readable text form.
Also I hope to write some POC code for SMS sending during the weekend