Systems and methods for controlling a power trowel. A power trowel includes a handle including a speed control input, a housing, a shaft connecting the handle and the housing, a safety mechanism located on the shaft, a blade assembly positioned below the housing, a motor located within the motor housing and coupled to the blade assembly, and a controller. The safety mechanism includes a safety lever configured to move in response to an uncontrolled condition of the power trowel. The controller is connected to the motor and the safety mechanism. The controller is configured to drive, in response to actuation of the speed control input, the motor, detect a movement of the safety lever from a first position to a second position, and perform, in response to the movement of the safety lever to the second position, a safety operation.