Methods and apparatus related to enabling a shopper to utilize a mobile electronic device to enhance the shopping experience. In the operation of the system, a first pair of card hoppers holds approximately two halves of a deck, which are then selectively interlaced together and supplied to the other pair of hoppers with the cards interlaced first into one of the second pair of hoppers and then into the other. On activation by relative displacement of the ends of the device, the electro-active structure twists around the minor axis due to the fact that the minor axis is curved. The mode control circuitry is configured to receive the control inputs to select one of the three modes of operation, and to alter one or more supply voltage levels to the array, for example, the Vss supply voltage using a Vss supply circuit and the Vdd supply voltage using a Vdd supply circuit, based on the selected mode of operation. The individual turns of the coil can be disposed and dimensioned so as to permit embossing of the circuit unit without restriction within an area conforming with the standard. The source of magnetic flux is positioned so as to be driven by a source of varying magnetic flux positioned along the railroad track.