Some embodiments provide a system for generating a memory-efficient representation of a sequence of electrically connected routing shapes. The probes are configured to extend beyond a first end of the shaft and are movable relative the shaft. The example method further includes comparing the one or more geographic features to a geographic feature map and generating a localized vehicle position based on the comparison between the one or more geographic features and the geographic feature map. The method includes causing the circuitry to respond to application to its input of an alternating current input signal by producing at its output an output signal suitable for driving an electronic light generating element, where the magnetic switch is used in regulating a current flowing through the output so as to maintain the current substantially at a selected value. It alternatively may comprise a data sampling circuit for over-sampling the bit data, a synchronizing circuit, a change point detecting circuit, and a data selecting circuit.