actually I am playing with UARTS and the beaglebone A5.
I want to controll a stepper motor driver by using the /dev/ttyO4.
When I use an USB Serial TTL 3,3 V converter (/dev/ttyUSB0)
everything works finde (minicome, ser2net, …)
But if using one of the boards UARTS (for example /dev/ttyO4)
the connection cannot bei done.
The stepper motor driver has also a USB Serial TTL 3,3V
interface. Thus the bone and the driver are at the same level.