Device for delivering a beneficial agent to a user includes a cassette including a cassette housing with a fluid reservoir, the cassette housing having a cassette base region, and a delivery tube. The device also includes a pump having a pump housing containing a pump assembly and having a receiving region to receive the cassette base region. The pump assembly includes a fluid drive component, a display, a plurality of input buttons. The pump assembly also includes a first processor coupled to the fluid drive component and the display and configured to reduce power to the fluid drive component and the display when the pump is in an inactive state, and a second processor coupled to the first processor and the plurality of input buttons, the second processor configured to provide an activation signal to the first processor when one or more of the plurality of input buttons is deployed.
