nrf52811 fatal error after connecting scope probe to UART RX pin

[Marcel]

Hello,

we have a strange proglem with nrf52811 on an own board

after uart initialization and connecting the scope (Saleae) probe to the RX pin the device outputs fatal error via RTT. before connecting the probe the uart channel is physically floating

we have tested the same setup with NINA-B301 (nrf52840) and the results seem the same - either the device goes into fatal state after some random time or after touching / moving the device

is there any recommendation on how to deal with situation like this?

marcel

[awneil]

Are you getting a framing error?

https://devzone.nordicsemi.com/f/nordic-q-a/49220/wakeup-the-nrf51422-with-uart-pins/196259#196259

[Marcel]

You know what - this just might be the problem! The initial fatals are gone so I believe this might just do the trick! Thanks for pointing me to the thread. I would not say this behavior is very intuitive