1. A biometric authentication unit comprising: a biometric object sensor comprising sensor elements and a sensor processor; and wake-on-event circuitry maintaining the sensor processor in at least one of a powered-off or powered down mode, and including a bulk biometric object sensor configured to detect a biometric object on or in a vicinity of the sensor elements and to power-on or power-up the sensor processor responsive to the detection of the biometric object on or in the vicinity of the sensor elements; wherein the sensor processor is configured to communicate with a host electronic device, the host electronic device including a host electronic computing device separate from the sensor processor, wherein, when the biometric object is present on or in the vicinity of the sensor elements, the sensor processor is configured to analyze one or more items of biometric bona fides data of the biometric object and received from the biometric object sensor to determine if the biometric object is desired to be imaged for use in authenticating a user providing the biometric object, wherein when the biometric bona fides data is determined to indicate that the biometric object is not desired to be imaged, the sensor processor commands the wake-on-event circuitry to monitor for the biometric object to leave contact with the sensor elements or leave the vicinity of the sensor elements, and wherein after commanding the wake-on-event circuitry to monitor for the biometric object to leave contact with or the vicinity of the sensor elements, the sensor processor returns to the at least one of the powered-off or the powered down mode and will be woken by the wake on event circuitry after the biometric object leaves contact with or the vicinity of the sensor elements.