MacBook trackpad: Exactly enough to be a scale

Apple’s Trackpad installed in MacBook Pro and MacBook Air has a surprising additional function: the built -in sensors can also be used as a scale. A corresponding app called Trackweight Published the developer Krish Shah on Github. The accuracy lies in the gram area, sometimes also below. However, a private API must be accessed to query.

Solid-State Technology including sensors

The trackpads in MacBooks have been relying on Solid-State Technology for years: The performerant cursor control units are mechanically immobile and capture movement as well as pressure using integrated sensors. Clicks are again simulated using the vibration engine (Tapic Engine) – in practice it feels very natural. Funnily enough, the system already provides grams: the printed print is conveyed accordingly.

Shah uses the library to access the data OpenMultitouchupport of the developer Takuto Nakamura. This makes all the necessary data accessible that Apple does not officially spend. However, the measurement of a weight is not entirely convenient: the trackpad can only determine the value if a finger (or another object with electrical capacity) is placed.

Fingers must lie down, otherwise it will not be read

This means that you have to put it on very gently (quasi floating). In addition, you have to place the object to be kept so that it does not bother finger contact. After all, you cannot easily weigh metal objects, as these can be recognized as a finger touch – Shah recommends to place a piece of paper or a light cloth in between.

Shah has carried out various calibration processes for Trackweight, which should ensure a precise measurement result – as long as the above restrictions are observed. Every user has to decide for themselves whether you really want to use a MacBook as a kitchen scale replacement. The app, which is explicitly intended for “experimental and educational purposes”, shows what is possible with modern sensors. It’s just a shame that it takes access to private APIs. OpenMultitouchupport provides a lot of exciting information about the trackpad.