RPi5 has 5 UARTs and you seem to pick the default one that is normally in use for debug/console.
Err no. Not unless things have changed recently.
On a Pi 5 the default for debug/console is the UART that's routed to the three pin debug header. That's ttyAMA10 not ttyAMA0 which is the usual default UART on GPIOP 14 & 15.
There is one potential point of confusion though: the /dev/serial0 symlink. On My Pi5 that points to the debug UART (ttyAMA0) which is different to the behaviour on previous models where it points to whichever UART is routed to GPIO 14 & 15.
Whether or not that would explain the behaviour the OP is seeing I have no idea.
Statistics: Posted by thagrol — Sun Jan 11, 2026 6:26 pm