Serial LTE Modem app in NCS main - glitch on TX before INDICATE

[Michal Mühlpachr]

Hi, 

NCS main, nRF9160 DK

git log -n 1 --oneline
4f916da03 (HEAD -> main, origin/main, origin/HEAD) west.yml: rebase OSS trees

SLM prj.conf changes:

CONFIG_SLM_START_SLEEP=y

CONFIG_SLM_WAKEUP_PIN=6

CONFIG_SLM_INDICATE_PIN=2

CONFIG_NRF_MODEM_LIB_TRACE_ENABLED=y

There is unexpected glitch on TX just beforfe INDICATE is active:

Regards,

Michal

[Albrecht Markus Schellenberger]

Hello Michal, 

Michal Mühlpachr said:

INDICATE was triggerd by this test scenario:

I’m not sure if I fully understand this. I assume that the indicate pin was triggered here which causes the glitch, right? 

52.70 <INDICATE transition> -> High 
52.78 <INDICATE transition> -> Low 

How was the pin triggered? It doesn’t seem to me that the SLM application did it itself? 

Regards, 

Markus