An electrical connector can receive a substrate having conductive tracks. The connector includes a housing with a port and at least one alignment feature that together define a direction of insertion. At least three function pins mounted to the housing each include contacts that electrically connect to one of the conductive tracks of a substrate inserted in the connector. A sense pin mounted to the housing has a contact that electrically connects to at least one of the conductive tracks of an inserted substrate. The sense pin can include a plurality of electrically-connected segments, each segment extending substantially parallel or substantially perpendicular to the direction of insertion of the substrate. Systems and methods for detecting an analyte in a bodily-fluid sample are also described.