I have a rover that I am now powering the M7 from a 3.3v reg that goes into Vin, Gnd goes to gnd of the camera and the Teensy MCU that I am using to control the rover. The regulator is getting its power from the 7.4v lipo batter which also powers the rover electronics and the motors. Its working but the M7 processor is getting hot as hell and I am not sure why. Connections to the Teensy are through the uart (serial commications).