sorry for my English
I've tried sending the command (echo 'h'> / dev / rfcomm0) from the Ubuntu terminal to my Arduino using Bluetooth hc-06. but he tells me rfcomm0 busy device.
my pc connects well to bluetooth, i use blueman, i have an arduino
the serial port of my arduino also tells me the same message when I try to open it (device / dev / rfvomm busy)
Thank you for your cooperation, I remain attentive