POWERED FASTENER DRIVER

A powered fastener driver includes a housing, a cylinder within the housing, the cylinder containing a pressurized gas, a piston within the cylinder and movable from a top-dead-center position to a bottom-dead-center position, a driver blade movably coupled to the piston, a lifter, a drive unit configured to provide torque to the lifter, and a sensor. The driver blade has a plurality of teeth defining a predetermined number of edges. The sensor is configured to detect an edge of one or more of the plurality of teeth and a controller in communication with the drive unit and the sensor. The controller is configured to count a number of edges detected by the sensor, compare the number of detected edges to the predetermined number of edges, and stop the drive unit when the number of detected edges is less than the predetermined number of edges.