False wakeup reduction for fingerprint sensors

In some implementations an apparatus may include a fingerprint sensor including a wakeup sensor portion and a transmitter portion. The wakeup sensor portion may be configured to send an activation signal to the transmitter portion due to a contact indication, corresponding to contact with an outer surface of the apparatus in the fingerprint sensor area, that equals or exceeds a contact indication threshold. A control system of the apparatus may include: a fingerprint sensor portion configured for controlling the transmitter portion and for determining, based at least in part on fingerprint sensor data obtained from an object in contact with the outer surface of the apparatus in the fingerprint sensor area, whether the object is a finger; a fingerprint image data processing portion; and a wakeup reduction module configured to control the contact indication threshold based, at least in part, on one or more time intervals between consecutive false wakeups.