Drug delivery device and dose recording system herewith

A dose recording system comprising:

• a drug delivery device comprising:
• a housing at least partially encasing a dose setting and drive mechanism, wherein the dose setting and drive mechanism comprises a piston rod and a dose setting member,
• wherein the dose setting and drive mechanism is configured to perform a dose setting operation for setting a dose to be delivered by the drug delivery device by moving the dose setting member relative to the housing and a dose delivery operation for delivering the set dose by axially displacing the piston rod along an axis, and
• wherein a maximum radial extension perpendicular to the axis of the dose setting member is smaller than a maximum radial extension perpendicular to the axis of a region of the housing located adjacent to the dose setting member;
• and
• an electronic module for attachment to the dose setting member of the drug delivery device, wherein the electronic module (2) comprises:
• at least one sensor,
• a processor configured to control operation of the at least one sensor and to process or store signals from the at least one sensor, and
• attachment features for attaching the electronic module to the dose setting member.