Hi!
Judging from these posts:
http://www.rcgroups.com/forums/showthread.php?t=1686498&page=27#post23859577 (Scroll to #401)
and
http://fpv-community.de/showthread.php?20672-Hobbywing-Skywalker-20A-Regler-mit-Atmel-MC (German)
The hardware has changed without notice. There seems to be no way to find out what hardware you have unless you peel off the heatshrink and have a look at the chips.
I don't expect these different hardwarerevisions to act exactly the same - like required on a multirotor. So if you can not get a stable flight with your APM (or other FC) please check, if all your esc are exactly the same.
EDIT: They are fake: http://www.rcgroups.com/forums/showpost.php?p=23898084&postcount=436
Cheers
Kraut
Rob
Replies
The Atmel Skywalker 20A are fake, confirmed by Hobbywing!
http://www.rcgroups.com/forums/showpost.php?p=23898084&postcoun...
Greets
Kraut Rob
Haha, i just flashed my skywalker 20A (sil) chip with the new blheli 9.4 fw. 3 of 4 esc work, one is screwed it drops speed randomly. So my apm quad will be grounded for weeks now until new ESC arrive. STAY AWAY FROM BLHELI 9.4 FW - at least with Skywalker 20A ESC it sucks.
BTW: What is better SimonK or Dji opto esc?
Cheers
Kraut Rob