Thanks jack123uk for your answer.
I modified my .yaml, now it looks like:
switch:
- platform: broadlink
host: 192.168.1.249
mac: 'xx:xx:xx:xx:xx:xx'
type: rm_mini
But, unfortunately, no changes… I got the same message:
2019-06-11 16:47:00 ERROR (MainThread) [homeassistant.components.broadlink] Failed to connect to device
On the other hand, I have tried the Broadlink Manager from Tomer_Klein
no success…