An electronic device includes a housing having an aperture and a main circuit board disposed in housing. The main circuit board includes an edge and a plurality of contact surfaces located at the edge proximate to the aperture, whereby a mating connector is connectable to the contact surfaces by inserting the mating connector into the housing from outside of the housing via the aperture. An update connector adapter includes a support structure and a mating connector mounted on the support structure. The mating connector includes a plurality of contact terminals for contacting the contact surfaces. The update connector adapter further includes an update connector mounted to the support structure. A programming unit is connectable to the update connector for programming the main circuit board. The control unit may be programmed by inserting the update connector adapter into the aperture and connecting the mating connector to the contact surfaces.