Firmware version

[demian054]

is there any firmware requirement?

I'm trying to use this custom component, but I'm getting those messages

Clearing RX buffer.
Sensor is not sending updates, attempting to leave config mode.
Sending command timed out! Is the sensor connected?
Clearing RX buffer.

note: using the Android app I can read the values

[TillFleisch]

Yes, there is a firmware requirement for some functionality (like buttons and switches), as these option were added to the sensor at a later stage.
I am currently using V2.04.23101915. Unfortunately, I can't recall what the minimum requirement is (probably anything starting with V2..). You can update the sensors firmware using the official HLK LD2450 App.

Make sure to go to though the troubleshooting section, in particular, try to use 5V and reliable connections. Long wires and improper wiring are known to cause this kind of issue. Try running a minimal configuration which does not include any other sensors/components.