The present invention provides a drug injection device (1) comprising a housing (2) extending along a longitudinal axis and comprising an exterior housing surface, an activation element (20, 50) configured to undergo movement relative to the housing (2) corresponding to an action performed on or by the drug injection device (1), a transducer (90, 91, 92) arranged on a transducer bearing portion (8.1, 9.1, 9.2) of the exterior housing surface, a processor (82) electrically connected with the transducer (90, 91, 92), and an energy source (95). The transducer bearing portion (8.1, 9.1, 9.2) is capable of deflection relative to other portions of the exterior housing surface, the activation element (20, 50) is arranged to deflect the transducer bearing portion (8.1, 9.1, 9.2) in accordance with said movement relative to the housing (2), the transducer (90, 91, 92) is adapted to register a deflection of the transducer bearing portion (8.1, 9.1, 9.2), and the processor (82) is configured to count deflections registered by the transducer (90, 91, 92).
