I am trying to control a BLDC motor without sensors using BEMF method and zero crossing detection. I managed to detect the zero crossing point but I am not sure if it is correct. I read that the hall sensors signal and BEMF ZCP have a phase shift of 30 degree. I measured the output of one hall sensor and the zero crossing point for the same phase (B):
How can I be sure that I really detect the zero crossing point ? Right now the motor runs in open loop, first I want to be sure when to switch to the next state because if I do it wrong it might burn the MOSFETs.