A computer-implemented method includes defining a valid scan or range of valid scans as a valid activity of an object in an application-specific activity taking place through a light curtain sensing area of a light curtain, defining an invalid scan or range of invalid scans as an invalid activity of the object in the application-specific activity taking place through the light curtain sensing area of the light curtain, storing parameters and activity-specific rules for processing a plurality of objects, monitoring and processing the object in the application-specific activity taking place through a light curtain sensing area of a low cost light curtain in conjunction with the stored parameters and activity-specific rules, and reporting a status and results of the processing of the object.