jmlat:
OK it seems it is an HC-05 ...I have no button on board
I looked at the Maryn Curre website and didn't find the exacly same board but I will try different procedures (upercase, lowercase...)
I already tried /r/n , /r , nothing but with no more result !
I'm sure you have proven it is an HC-05 by virtue of using the KEY and actually getting a response. Unless Martyn has something to say about it, I believe there are essentially two types of HC-05 - those on a board with a button, and those without. The procedures are slightly different but I'm sure the code is the same. Of course this is your golden opportunity to come up with something nobody has seen before, but you might clarify things by coming forth with which particular breakout board you are using. This is usually clearly marked on the back as a code e.g. JY-MCU ( never has a button) or ZS-040(sometimes has a button, sometimes not). I'm guessing you have a JY-MCU
If you are certain that you have had a response before, this can't be a serious problem - just something stupid that will likely only happen once.