AT module and RN2483: not working with my Linux box

Thank you Dr Azzy, I did your recommendation and found out that it was not a clock problem. Then I focussed on the init procedure of the module and found out that the problem was tricky, due to an involuntary break condition during module power up which puts the module in a locked state. So, I reworked the init procedure carefully to avoid this break condition and now the module works perfect. I also confirm that your breakout is a great device.
GeekBot