Can I use a Raspberry PI model B to interact directly to a router debug console (undocumented) via "screen".
TX <-> RX RX <-> TX GND <-> GND # screen -L /dev/ttyAMA0 115200,-parenb,-cstopb,cs8
Probable serial parameters: 115200, 8N1. Tests confirm 3.3v by following this tutorial.
The "mini UART" seems problematic because of the fixed frequency so I will disable bluetooth and use the PL011 UART via /dev/ttyAMA0.
I have read that I can also use any GPIO as TX and RX but maybe this could add some more problems since I would need to find or program a driver?
Also note that I use a custom 64Bit custom kernel/OS with the kernel configured only for this purpose. I know about USB to TTL cable and ordered one... I have some basic electronic components and tools if required but would prefer a direct connection if this is realizable.