Implementations of the present disclosure are directed to conserving energy of an injection device by using a sensor attached to the housing, configured to detect a signal associated with an amount of medicament within the injection device and to generate a sensor signal based on the signal, a control component coupled to the sensor, configured to harvest energy to process the sensor signal and to generate injection device data, and an antenna coupled to the control component and configured to transmit a radio frequency signal based on the injection device data.