So finally it seems to fly ! As my ESC have kind of no voltage regulator, I could’nt use Dshot protocol unless my batt would get under 3.8v… So I kept searching on Oneshot.
As Nigelsheffield said that programming by Tx should be active to do the quick calibration he did (see rcgroups 's thread linked on 1st post), I went again with BHelisuite through my 4 ESCs and activated programming by Tx for all. There I noticed that all of them had very different values for min and max throttle. I think I didn’t pay much attention few days before when I unticked programming by Tx. At this time I wrote down values from one of them and thought it was same for all.
I tried Nigelsheffield’s quick calibration of esc that didn’t work I don’t know why. And, finally, I went through all for ESCs again, unticked tx programmation, and set throttle values 1000 to min and 1700 to max. Then in silverware’s dvr_esc.c, I reported those values for min and max and set throttle off to 900. Checked that with “throttle to motor” enabled. Ok, good and linear response. Then tried without… And it flies !! Not well but now I can start learning about tunning PIDs with the good help of SiverVise !
So thanks again all of you for your support, alone I would spend at least one week more on it !