I am so happy !
I have discover the problem. In fact, my USB David's key wasn't connected correctly on my pc.
Window hadn't reinstalled the Key after the last crash.
I have unplugged and plugged the key, and miracle : David run correctly.
And for the speed problem with my motor, the guilty Was the counter in the sketch.
He slow down the motor and I put the value at 5 and he run normally.
Scanning without panel is very cool.
Thank's for your support.