rePhill provides a compact and convenient platform for monitoring supply levels in a variety of shop settings. Although designed for use in a machine shop in conjunction with a bin storage system for small components such as nuts, screws, and washers, the application concept can be scaled in both number of monitored storage containers and component size.

For the demonstration of the project’s functionality, we installed a force-sensitive resistor (FSR) beneath each of two storage bins, and connected each to an Arduino Uno board. The rePhill graphical user interface (GUI) contains panels for the individual containers, which, upon initialization of the program, are initially empty. The user can then add items of a certain type to one or more of the available bins via interactions with drop-down menus that hold the available options for the chosen shop component based on an Excel spreadsheet database. Pre-loaded in the database are the details for objects of type ‘Screw’, ‘Nut’, and ‘Washer’, with a myriad of materials, thread size, and dimensions.

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Once the bins contain items, the program uses the voltage reading from the FSR/Arduino interface to check whether the weight of objects present in the containers is below a threshold value. As soon as the weight falls below this critical value, an event is triggered that displays a message in a ‘Notifications’ panels alerting the user that the corresponding bin is running low on the items. This notifications panel can be cleared and the bin refilled.