nrf52840 BGA footprint P0.22 config as UART0 RX mode issue

[liyang]

hi,

nrf52840 BGA footprint P0.22 config as UART0 RX mode, don't receive any data, but config as other pin P1.06, work normally. 

and I also test QFN footprint with nrf52840 DK board, P0.22 can work,

so BGA bug ?

[Turbo J]

Nope: P0.22 is connected to the QSPI memory chip and cannot be used as UART RX unless this connection is openend somehow.

[liyang]

hi, Turbo:

I have disconnect QSPI, I find that uart rx will trigger ERRORSRC RW BREAK, how to resume it?

[Turbo J]

Probably by just commenting out some APP_ERROR_CHECK()...

Seriously: You want to check the UART waveform with an oscilloscope. Usually there is a good reason why the RX break flag triggers: The RX line is low for longer than a byte.