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TrackWeight: Turn your MacBook's trackpad into a digital weighing scale

github.com

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Re: TrackWeight: Turn your MacBook's trackpad into a digital weighing scale

#81

Post by dtgriscom »

incanus77 wrote: post #18

This reminds me of how, twenty years ago, I used the PowerBook’s hard drive vibration sensor to rig up a seismograph to measure construction noise: https://allthegooddomainsweretaken.justinmiller.io/2007/04/0...

I wrote that software, called SeisMac. Someone figured out the Apple-private API for the Sudden Motion Sensor that parks your laptop's hard drive if it detects free-fall. Working from that, I wrote a free app that used the API to show three-axis acceleration graphs. I was proudest of the calibration utility, which had you tip your laptop on its side (with properly rotated dialogs!), and then on its screen.

People would send me recordings from all over the world (e.g. on a ship in the Drake Passage showing enormous surges). It was a lot of fun, and I even got an educational grant to improve it.

Big bummer when Apple switched to solid-state drives (well, a bummer for my one small reason...)

[0]: https://en.wikipedia.org/wiki/Sudden_Motion_Sensor

Re: TrackWeight: Turn your MacBook's trackpad into a digital weighing scale

#82

Post by hbn »

cluckindan wrote: post #57
pmxi wrote: post #10

This is clever! and potentially useful too. Have you done any testing to determine how precise and accurate this is? I suspect their must be a lot of variance between laptops, since this isn’t an intended use case.

I would assume Apple hardware comes precalibrated. Homogeneity is everything for their product lines, down to individual calibration of screens and audio hardware. It would be weird to get a new laptop and have its trackpad feel different.

They have a setting for adjusting the pressure needed to activate a click.

I wonder if that affects this app at all.

Re: TrackWeight: Turn your MacBook's trackpad into a digital weighing scale

#85

Post by mietek »

dotancohen wrote: post #66
doubled112 wrote: post #40

Earlier quoted context omitted.

The recipe was on your phone/tablet and there was no way you were taking your gloves off?

Nice. No, I preemptively armed myself with a carrot before taking the dog for a walk in cold weather. I only had a non-stylus smartphone for a year and a half before whimpering back to the Note series. It's what keeps me in the Samsung sphere of influence.

I used my nose.

Re: TrackWeight: Turn your MacBook's trackpad into a digital weighing scale

#86

Post by jbverschoor »

cryptoz wrote: post #61
benoau wrote: post #3

There used to be iPhone apps that did something similar - https://www.theverge.com/2015/10/28/9625340/iphone-6s-gravit...

You can use any phone with a barometer to make a scale. All iPhones since the 6, and all the Pixels, and Samsung flagships have one. You get a zip loc bag, blow some air into it, put your phone in running an app that shows the pressure in a big font (so you can see it through the ziploc). Then you put an object of known weight on it like a quarter (balanced carefully on top of the air-filled ziploc) and note the pres…

Dropbox shouldn’t exist either bc we have rsync ;)

Re: TrackWeight: Turn your MacBook's trackpad into a digital weighing scale

#87

Post by acct-litter-al »

acct-litter-al wrote: post #78
namdnay wrote: post #17

Earlier quoted context omitted.

Could a small piece of conductive foam or some cleverly layered tin foil+paper work? So put the object on the shim (which has a known or even negligeable weight)

I once put some aluminum duct tape completely over the touch pad of an old laptop to see what would happen. Turns out it induced enough "eddy currents" to make the mouse move around the screen without me touching it--in a way, visualizing the currents! I connected the foil to ground using a small strip of the tape to the ground metal of a USB port on the side and it disabled the touch pad.

Looking back, it would have been interesting to code up a program to record the movement of the mouse as a trail of pixels...

Re: TrackWeight: Turn your MacBook's trackpad into a digital weighing scale

#89

Post by bagels »

jmb99 wrote: post #41
hackmiester wrote: post #20

Earlier quoted context omitted.

This worked all the way up through the iPhone Xs.

The single most irritating killed feature from Apple. Redesign half of their UI to rely on 3D Touch to make sense, then get rid of 3D Touch without redesigning the UI. Previewing links, moving the cursor, interacting with items, they’re all “press and hold until haptic feedback” instead of “quickly press hard and get immediate feedback.” Easier to accidentally trigger, slower to trigger on purpose.

I hated when my mother in law came to me for help using her iPhone. She had a hard time controlling and understanding 3d touch.

Re: TrackWeight: Turn your MacBook's trackpad into a digital weighing scale

#90

Post by kiddico »

cryptoz wrote: post #61
benoau wrote: post #3

There used to be iPhone apps that did something similar - https://www.theverge.com/2015/10/28/9625340/iphone-6s-gravit...

You can use any phone with a barometer to make a scale. All iPhones since the 6, and all the Pixels, and Samsung flagships have one. You get a zip loc bag, blow some air into it, put your phone in running an app that shows the pressure in a big font (so you can see it through the ziploc). Then you put an object of known weight on it like a quarter (balanced carefully on top of the air-filled ziploc) and note the pres…

I'm adding this to my list of obscure tools I have in the back of my head
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