The invention is concerned with a simple and reliable manner of monitoring a handling or use of injection devices by means of a reusable electronic module. According to the invention, a displacement of a component of the injection device between an initial position and an intermediate position, and a subsequent displacement of the same component between the intermediate position and a final position essentially identical with the initial position is observed by one and the same sensor comprised in an electronic module separate from the injection device. A status or state of the injection device is then inferred in the electronic module from these two observations by way of digitally processing sensor output information. The invention thus enables secure, easy and cost-effective operation of components, devices and systems for the generation, collection and distribution of data associated with the handling or use of the injection devices.