Something about encoder connection

   i have two VESC 6.4,when im trying position control，i used both ABI encoder and AS5047 encoder, ABI encoder is easy to connected by the manual,

and it works fine,but when i connect VESC to AS5047,the chip burned,so i think if there is gndloop.

   so im wondering should we do not connect gnd?   

   what's the connecting difference between 3.3V opration and 5V opration?

   How we deal with the resistant R1 and R2？in my AS5047 PCB broad there is only C1 and C2.