What is the best way to find out whether the esc ground connection is connected to the battery negative? 
The battery is 8s li-po, so the voltage is between 25,6v(empty) and 33,6v(full)
I was having trouble with the code when i was trying to read rpm and using that to "limit" the "power",
but now i am trying with the shunt, and it looks ok, so for now i dont need any help with the code... 
but thanks for asking..
The bigger problem is the connection off all that stuff, i will manage the code somehow... 