Using MacBook's trackpad as digital weighing scale

Summary

TrackWeight Turn your MacBook's trackpad into a precise digital weighing scale TrackWeight is a macOS application that transforms your MacBook's trackpad into an accurate weighing scale by leveraging the Force Touch pressure sensors built into modern MacBook trackpads. IMG_7303.mov To use it yourself: Open the scale Rest your finger on the trackpad While mainting finger contact, put your object on the trackpad Try and put as little pressure on the trackpad while still maintaining contact. This is the weight of your object How It Works TrackWeight utilizes the Open Multi-Touch Support library by Takuto Nakamura to gain private access to all mouse and trackpad events on macOS. This library provides detailed touch data including pressure readings that are normally inaccessible to standard applications. The key insight is that trackpad pressure events are only generated when there's capacitance detected on the trackpad surface - meaning your finger (or another conductive object) must be in contact with the trackpad. When this condition is met, the trackpad's Force Touch sensors provide precise pressure readings that can be calibrated and converted into weight measurements. Calibration Process The weight calculations have been validated by: Placing the MacBook trackpad directly on top of a conventional digital scale Applying various known weights while maintaining finger contact with the trackpad Comparing and calibrating the pressure readings against the reference scale measurements Ensuring consistent accuracy across different weight ranges It turns out that the data we get from MultitouchSupport is already in grams! Requirements macOS 13.0+ (for Open Multi-Touch Support library compatibility) (for Open Multi-Touch Support library compatibility) MacBook with Force Touch trackpad (2015 or newer MacBook Pro, 2016 or newer MacBook) (2015 or newer MacBook Pro, 2016 or newer MacBook) App Sandbox disabled (required for low-level trackpad access) (required for low-level track...