The Emax SimonK that run with my APM do not work with Pixhawk, they are simply not compatible. Can any one suggest which ESC's (30A) will be compatible with Pixhawk. What i've found is that Silabs based ESC with BLHeli are also not compatible, perhaps Atmel based may work, can any one suggest (from experience, not theory) which ESC's (preferably simonk) are suitable and where to buy them? need at least 6 for my Hex.

Using ztw with pixhawk. Without any Problem. Simonk firmware

Thanks for the quick response, where can i get them?

I buy from factory directly. But ucan find them on aliexpress.  Search for ztw ESC.

Very reliable . using on all my filming setups
X8 carrying black magic production camera too..

With sunnysky motors

Thanks a ton  Sujith. Bought this pixhawk few months back but was never able to use. Am using Sunnysky too so these ESC's will be perfect.

Need to move to pixhwak, specially now that Arducopter will stop APM support from 3.2.1 i think.

They are good escs. Well built. Did over 100 flights with a opro setup . no problems whatso ever. They are rated at 600 hz

check here

Afro ESC 30Amp Multi-rotor Motor Speed Controller (SimonK Firmware)
http://www.rcproduct.in/all-speed-controllers/24-afro-esc-30amp-multi-rotor-motor-speed-controller-simonk-firmware.html?search_query=afro&results=7


Find out more Esc's
http://www.rcproduct.in/22-all-speed-controllers

Is the microcontroller Silabs or Atmel in Afro Esc's?

Atmel afro.