A detection system in a portable assay reader device is enabled or activated after a user applies a manual force to a portion of the reader device, to an object supporting the assay test strip, or to the assay test strip itself. The movement moves a switch from an open state to a closed state. The closed state enables a detection system to monitor one or more test regions in the assay test strip for a reaction. The detection system can include one or more imagers, one or more electrical detectors, one or more magnetic detectors, or one or more optical detectors that monitor the one or more test regions for applicable visible, electrical, magnetic, or optical reactions, respectively. The one or more imagers or detectors transmit data to a processing device to determine the results of a test.