A medication delivery device comprising: a device body ; a dose setting member attached to said device body and rotatable relative to said device body about an axis of rotation (AA) during dose delivery; and an actuator attached to said device body; characterized in that the medication delivery device further comprises: a sensed element attached to and rotationally fixed with said dose setting member, said sensed element including axially extending surface features radially-spaced from one another about the axis of rotation of said dose setting member, wherein said sensed element is rotatable relative to said actuator during dose delivery in relation to the amount of dose delivered; a rotational sensor attached to said actuator, wherein said rotational sensor comprises a switch, said rotational sensor including a movable element (103, 326. 492, 692) positionable to slidably contact the axially extending surface features during rotation of said sensed element relative to said actuator during dose delivery, said rotational sensor configured to generate a signal in response to a triggering of the movable element over the axially extending surface features during the rotation of said dose setting member, wherein the movable element alternately engaging or disengaging the axially extending surface features is operable to trigger the switch and generate said signal; and a controller operatively coupled to the rotational sensor, wherein, in response to receiving the generated signal from said rotational sensor, the controller is configured to determine a number of the axially extending surface features passing the movable element of the rotational sensor during dose delivery. a device body ; a dose setting member attached to said device body and rotatable relative to said device body about an axis of rotation (AA) during dose delivery; and an actuator attached to said device body; characterized in that the medication delivery device further comprises: a sensed element attached to and rotationally fixed with said dose setting member, said sensed element including axially extending surface features radially-spaced from one another about the axis of rotation of said dose setting member, wherein said sensed element is rotatable relative to said actuator during dose delivery in relation to the amount of dose delivered; a rotational sensor attached to said actuator, wherein said rotational sensor comprises a switch, said rotational sensor including a movable element (103, 326. 492, 692) positionable to slidably contact the axially extending surface features during rotation of said sensed element relative to said actuator during dose delivery, said rotational sensor configured to generate a signal in response to a triggering of the movable element over the axially extending surface features during the rotation of said dose setting member, wherein the movable element alternately engaging or disengaging the axially extending surface features is operable to trigger the switch and generate said signal; and a controller operatively coupled to the rotational sensor, wherein, in response to receiving the generated signal from said rotational sensor, the controller is configured to determine a number of the axially extending surface features passing the movable element of the rotational sensor during dose delivery. <EOS>