first of all: I’m new to raspberry

I.ve just bought a raspberry PI 4 together with an EnOcean PI 868 module to set up a house automation system. To make it run I’ve tried the steps described on the element14 site and also used sudo stty -F /dev/ttyAMA0 57600 + hexdump -C < /dev/ttyAMA0 to see at least a single byte received .. with no success.

Of course I’ve read about the nessessary setup for PI3 like

• enabling serial
• disabling serial console
• adding dtoverlay=pi3-miniuart-bt to /boot/config.txt

and did so. The only differnece I’ve seen is in /boot/cmdline.txt: tototrials say ‘find a line startiing with wc_otg.lpm_enable=0 and remove console=serial0,115200 but I don’t have such al line.

Edit

some more things I’ve found or tried so far:

• the EnOcean PI 868 uses serial UART gpio 14 &15 and web research always brings me to these points, which are in genereal related to PI 3B but seem to be true for PI4 too:
• /dev/ttyAMA0 is by default used for blutooth, /dev/ttyS0 as ‘miniuart’ for serial
• you can switch devices by adding dtoverlay=pi3-miniuart-bt to /boot/config.txt
• /dev/ttyAMA0 is also used for serial if you disable blutooth completely with dtoverlay=pi3-miniuart-bt to /boot/config.txt
• the simplest way to see if anything is received is by calling stty -F /dev/ttyAMA0 (or ttyS0) 57600 (115200 in other posts) + hexdump -C < /dev/ttyXXX