Serial LTE modem strange double Ready after wakeup

[Michal Mühlpachr]

nRF9160 DK NCS v1.6.0, SLM with:

CONFIG_SLM_GPIO_WAKEUP=y

CONFIG_SLM_INTERFACE_PIN=24

Sometimes after at#xsleep=0 and several pulses on pin 24 SLM wakeups with double Ready response:

AT

OK

at#xsleep=0

Ready

at#xsleep=0

Ready

Ready

AT+CFUN?

+CFUN: 0

OK

[Michal Mühlpachr]

[Albrecht Markus Schellenberger]

Hello Michal,

is this something you observe in NCS v1.6.0 only, or can you reproduce the behaviour in earlier versions as well?

I might want to be interested in how those “several pulses” look like. Can you elaborate?

Regards,

Markus

[Michal Mühlpachr]

It is observation related to NCS v1.6.0 only.
I make "several pulses" by scratching GND plane on USB connector by wire.
It usually takes 3-5 trys (sleep-wake) to get double Ready from SLM during wakeup.

[Albrecht Markus Schellenberger]

Okay, thanks! Will be reported to our application team.

Regards,

Markus

[Albrecht Markus Schellenberger]

Hello Michal,

Our development team has done some analysis on this, and they are able to reproduce the behaviour you are describing, but not in NCS v1.7.0.

If you are not already have upgraded to v1.7.0, could you please test this patch and check if that solves the issue?

138051_double_idle_wakeup.patch

Thanks and regards,

Markus