While the Apple Pencil is designed as a sketching tool for creative professionals, MacRumors reader Simon Gladman has created three Swift demo apps that show the accessory being used for three unconventional purposes -- as a weight scale, controlled synthesizer and 3D controller for image editing.

PencilScale


PencilScale, based on Goodman's Plum-O-Meter, is an experimental app that uses a homemade harness to turn the Apple Pencil into an electronic scale that is highly sensitive, but not incredibly accurate.

The experiment works by subtracting the touch's force from a base weight, which is "set as the current touch force when the 'zero' button is pressed," and multiplying it by 140 for a very rough weight in grams.

PencilSynth


PencilSynth is an AudioKit-powered synthesizer that can be controlled by the Apple Pencil depending on its orientation and position.

  • Apple Pencil's horizontal position on the screen controls frequency

  • Apple Pencil's vertical position on the screen controls the modulating multiplier

  • Apple Pencil's altitude angle controls the carrier multiplier

  • Apple Pencil's azimuth angle controls the modulation index

PencilController


PencilController is an experimental image processing app that uses the Apple Pencil as a controller for the fine setting of parameters on Core Image filters.

The demo has three image filtering modes:

  • Hue/Saturation - Apple Pencil's azimuth angle controls hue and its altitude angle controls the saturation

  • Brightness/Contrast - Apple Pencil's altitude angle along North/South controls contrast and the angle along West/East controls brightness

  • Gamma/Exposure - Apple Pencil's altitude angle along North/South controls exposure and the angle along West/East controls gamma

Gladman explains that "the app uses a spring loaded pattern, so the user needs to hold down one of the mode keys in the bottom left of the screen to stay in the filtering mode."

The source code for all three projects is available on GitHub.

Related Roundup: iPad Pro
Buyer's Guide: iPad Pro (Don't Buy)
Related Forum: iPad Accessories

Top Rated Comments

FlexMonkey Avatar
128 months ago
I know this is sounds cool. But come on guys I'm tired of hearing this non-sense use of technology. There is abviously a much better device for such thing and it doesn't cost a lot of money to have one. I'm talking about the scale and somebody did it on iPhone 6S 3D Touch too. It's because you can it doesn't mean you have too.
Hi!

I'm actually the same guy that did the "Plum-O-Meter" for weighing things on an iPhone :)

Of course there are better devices, but I'm interested in experimenting, tinkering and playing then seeing what results. Actually, using the Pencil as a controller works really well for the fine adjustments in the image processing app and the fact the it has five degrees of freedom makes it a unique input device for the audio app.

Without some left field thinking, we'd all be using abacuses!

Cheers!

Simon
Score: 16 Votes (Like | Disagree)
Waxhead138 Avatar
128 months ago
Aren't the phrases "Highly Sensitive" and "Not Incredibly Accurate" a bad combination under pretty much any circumstance?

.....As a side note, those two phrases remind me of almost every girlfriend I've ever had, the first phrase typically causing the second.... ;)
Score: 7 Votes (Like | Disagree)
teslo Avatar
128 months ago
I know this is sounds cool. But come on guys I'm tired of hearing this non-sense use of technology. There is abviously a much better device for such thing and it doesn't cost a lot of money to have one. I'm talking about the scale and somebody did it on iPhone 6S 3D Touch too. It's because you can it doesn't mean you have too.
yeah, why would anyone ever want to do things?

i, for one, am witnessing exactly what i'd hope would start happening upon the release of a new device: tinkering, feedback, and constructive criticism. i'm sorry you're tired, i hear energy drinks are all the rage nowadays.
Score: 6 Votes (Like | Disagree)
Makosuke Avatar
128 months ago
Aren't the phrases "Highly Sensitive" and "Not Incredibly Accurate" a bad combination under pretty much any circumstance?
Nope, from a scientific terminology perspective, that actually makes perfect sense.

Accuracy, scientifically speaking, is how close to the real value a measurement will produce.

Precision (aka sensitivity) is how small of a quantity you can measure, accurately or otherwise.

And repeatability is how close to the same value taking the same measurement at two different times will produce, accurately, precisely, or otherwise.

So: An accurate scale will tell you something weighs 502 grams when it weighs 502 grams. A precise scale will tell you that something weighs 498.93 grams, although it might actually weigh 502.00 grams if the scale is not also accurate. And a repeatable (and precise) scale will tell you that something weighs 498.93 grams every time you weigh it, although if it's not also accurate it might really weigh 502 grams.

This particular "scale", silly or otherwise, will give you a lot of digits of precision on the weight measurement, so it's quite precise. It however isn't calibrated at all, so the accuracy is bad. No idea whether it's repeatable or not.
Score: 5 Votes (Like | Disagree)
nagromme Avatar
128 months ago
Think what you could do with 3 pencils! You could control that synthesizer with one, and jam the other 2 in your ears until the racket stops.
Score: 4 Votes (Like | Disagree)
joueboy Avatar
128 months ago
I know this is sounds cool. But come on guys I'm tired of hearing this non-sense use of technology. There is abviously a much better device for such thing and it doesn't cost a lot of money to have one. I'm talking about the scale and somebody did it on iPhone 6S 3D Touch too. It's because you can it doesn't mean you have too.
Score: 3 Votes (Like | Disagree)

Popular Stories

iOS 26 on iPhone Feature

Here's When iOS 26 Rolls Out Today in Every Time Zone [Update: Out Now!]

Monday September 15, 2025 12:00 am PDT by
Update 10:06 a.m.: iOS 26 is rolling out now, though it may take a bit for all users to see it, so keep checking! Today's the day! Apple is about to release iOS 26, which will deliver the biggest redesign since iOS 7 and bring a range of new features and improvements to iPhones worldwide. It's Apple's biggest software update of the year, and Apple announced at last week's iPhone event that...
Tim Cook Rainbow

Apple Reportedly Plans to Launch These 10 Products in 'Coming Months'

Sunday September 14, 2025 8:45 am PDT by
Apple's annual September event is now in the rearview mirror, with the iPhone 17, iPhone 17 Pro, iPhone 17 Pro Max, iPhone Air, Apple Watch Series 11, Apple Watch Ultra 3, Apple Watch SE 3, and AirPods Pro 3 set to launch this Friday, September 19. As always, there is more to come. In his Power On newsletter today, Bloomberg's Mark Gurman said Apple plans to release many products in the...
iOS 26 Battery Glass Feature

Apple Says Installing iOS 26 Might Impact Battery Life

Monday September 15, 2025 10:56 am PDT by
In the iOS 26 release notes, Apple is warning iPhone users that installing the new software might have a temporary impact on battery life, which is normal. A new support document explains that major iOS updates require background setup like indexing data and files for search, downloading new assets, and updating apps. Further, Apple says that new features could require more resources,...
AirPods Pro Firmware Feature

AirPods Pro 2 and AirPods 4 Get iOS 26 Features With New Firmware Update

Monday September 15, 2025 10:50 am PDT by
Apple today released updated firmware for the AirPods Pro 2 and the AirPods 4, introducing support for the new AirPods features that are included in iOS 26, iPadOS 26, and macOS Tahoe. The firmware has a build number of 8A356, and it replaces the current 7E93 firmware. With Apple's new software updates, the AirPods Pro 2 and the AirPods 4 support better audio quality for phone calls and...
iphone 17 lineup

iPhone 17 Models Launch on September 19 With These New Features

Friday September 12, 2025 7:58 am PDT by
Apple will launch its new iPhone 17 lineup and ultra-thin iPhone Air in stores on Friday, September 19, and the company has already shown off the new devices at its fall event, which ran with the the tagline "Awe dropping." The iPhone 17 series brings a host of new features and enhancements. Here's a rundown of the biggest upgrades and changes: iPhone 17 Display Changes The iPhone...
apple n1 chip

Apple's New N1 Chip in iPhone 17, iPhone 17 Pro, and iPhone Air Has a Wi-Fi 7 Limitation

Saturday September 13, 2025 10:01 am PDT by
The latest iPhone 17, iPhone 17 Pro, iPhone 17 Pro Max, and iPhone Air models are equipped with Apple's all-new N1 chip for Wi-Fi 7, Bluetooth 6, and Thread connectivity. However, the chip has a Wi-Fi 7 bandwidth limitation. According to FCC documents reviewed by MacRumors, the N1 chip in all of the new iPhone models supports up to 160 MHz channel bandwidth for Wi-Fi 7, short of the...
iPhone 17 Pro Air Boxes

iPhone Air and iPhone 17 Pro Boxes Revealed

Sunday September 14, 2025 1:36 pm PDT by
T-Mobile President Jon Freier today shared real-world photos of Apple's boxes for the iPhone Air, iPhone 17 Pro, and iPhone 17 models, which launch on Friday. Image Credit: Jon Freier Apple has typically included iPhone box renders in its product environmental reports, but it did not do so for the latest models. However, Apple's iPhone Upgrade Program page does offer some images of the boxes, ...