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Reading the undocumented MEMS accelerometer on Apple Silicon MacBooks via iokit
- baybal2 8mo ago[dead]
- greyface- 8mo agohttps://osxdaily.com/2006/12/06/macsaber-turn-your-mac-into-a-lightsaber/ https://osxdaily.com/2006/12/06/macsaber-turn-your-mac-into-...
- totetsu 8mo agohttps://techcrunch.com/2008/06/01/the-macbook-air-thin-enough-to-slice-a-cake/ https://techcrunch.com/2008/06/01/the-macbook-air-thin-enoug...
- userbinator 8mo agoundocumented The one thought that comes to mind is this: "Your warranty claim was denied because we determined that the laptop was subjected to a sudden shock."
- sysguest 8mo agoidk you can just use simple liquid-container or sticker? maybe apple was preparing for "carrying-around laptop experience"?
- XorNot 8mo agoThat's an entirely different product build path compared to the electronics production line though. If a pick and place machine can drop it on and reflow it, that's what you want.
- sysguest 8mo agowell it would be hardened when contact with air or something see "Shipping Damage Indicators"
- altairprime 8mo agoDid it park the drive heads?
- consp 8mo agoBack in the days this was to lock up the hard disk read/write head. Maybe a relic from those times instead?
- userbinator 8mo agoApple is not known for backwards-compatibility, and they were already using SSDs in their laptops long before switching to ARM.
- tpmoney 8mo agoFrom elsewhere in this discussion, it's likely for the motion sickness functionality they added in recent years: https://support.apple.com/en-om/guide/mac-help/mchla3c4f1da/mac https://support.apple.com/en-om/guide/mac-help/mchla3c4f1da/...
- krackers 8mo ago>have a hard to find mems accelerometer managed by the sensor processing unit How did OP even know that an accelerometer exists in the first place?
- rustyhancock 8mo agoThe presence of the sensor is well documented as part of Apples Sudden Motion Sensor hard drive protection system. How to access it is undocumented.
- future10se 8mo agoAaackshually, the Sudden Motion Sensor was introduced on 2005 in the PowerBook G4, and continued through the intel MacBooks with hard drives. While officially undocumented, people figured out how to access it back then, with novel uses like smacking your MacBook to change spaces (virtual desktops) or swinging the Mac around to make lightsaber noises. - https://www.youtube.com/watch?v=6uvQTTPr9Rw https://www.youtube.com/watch?v=6uvQTTPr9Rw - https://osxdaily.com/2006/12/06/macsaber-turn-your-mac-into-a-lightsaber/ https://osxdaily.com/2006/12/06/macsaber-turn-your-mac-into-... (I should know, I was in university back then and swung my Mac around like an idiot, lol.) On the first Retina MacBook Pro 15" in 2012, and moving forward with all MacBooks that were SSD-only, they removed the SMS as it was not needed. To my knowledge, this is the first time we're hearing that Apple Silicon machines have an accelerometer on the SoC, officially or otherwise. It's also certainly not branded or marketed as the SMS was. (https://support.apple.com/en-us/100871 https://support.apple.com/en-us/100871) Happy to be corrected on this!
- 1e1a 8mo agoI think there's some sort of motion sickness reducing feature in MacOS Tahoe which would require an accelerometer.
- lelandfe 8mo agoIn 2022 "a little birdy pointed out an accelerometer" to iFixit on their teardown of an M2 MBA: https://www.ifixit.com/News/62674/m2-macbook-air-teardown-apple-forgot-the-heatsink#:~:text=it%20run%20hot.-,Chip%20Identification,-That%20USI%20chip https://www.ifixit.com/News/62674/m2-macbook-air-teardown-ap... They could not figure out what it was for. Ars Technica commenters at the time believed it was to record drops so Apple repair teams could rebuff requests :)
- seductivebarry 8mo agoWay back in ~2008 I wrote the Newton Virus https://www.everita.com/how-the-newton-virus-was-made https://www.everita.com/how-the-newton-virus-was-made + https://www.youtube.com/watch?v=eh75j6OHhRc https://www.youtube.com/watch?v=eh75j6OHhRc (sorry for the broken images, need to update that site). Between that and using a hidden API to take screenshots of each individual element on your desktop (from icons, to taskbar, to windows) the effect was pretty believable. One of the most fun (and frustrating) projects I ever worked on.
- tmslnz 8mo agoTroika! Hello from a friend in London :)
- swiftcoder 8mo agoOfftopic, but I have nostalgic feelings for the era of MacBook in the video
- outadoc 8mo agoI've tried to find this for so long. I remember seeing it at the time as a teenager and thinking it was SO COOL. Basically made me discover Apple and want a Mac. :)
- directmusic 8mo agoWhen I saw the post the Newton Virus was the first thing I thought of. Thanks for making it. I remember showing my family the video and remarking about how cool it was.
- 486sx33 8mo ago[dead]
- ggm 8mo agoCould this be used as "shake your mac for highly random seed" bits?
- c22 8mo agoProbably not as random as you want it to be.
- sysguest 8mo agowell wouldn't it add up? someWhatRandom1 xor someWhatRandom2 xor notRandom3 xor ... should be more 'random' than just 'someWhatRandom1'
- throawayonthe 8mo agoi'm not sure it would necessarily be more random if you're mixing in a lower-entropy source which the accelerometer probably is
- LoganDark 8mo agoXOR is the worst hashing function imaginable, especially if the data isn't truly random, because it can cancel out to become even less random! It's better to use a KDF or something. Even a block cipher should work far better than XOR.
- mlajtos 8mo agoShake your Mac to undo would be consistent with iPhone, iPad, Vision Pro. Yes, you shake your head to undo when wearing AVP.
- RupertSalt 8mo agoThis is a milder version of “Shake to Reboot” which is standard for all Etch-a-Sketch models
- 1e1a 8mo agoThere's lots of noise in the accelerometer readings, even without shaking
- JSR_FDED 8mo agoIf it can read your heartbeat from your wrists resting next to the trackpad, maybe it can use that as a user satisfaction signal for gratuitous UI changes.
- pbhjpbhj 8mo agoIf it's sensitive enough to read a heart beat, then surely it can be used as a covert microphone?
- rcxdude 8mo agodepends on the bandwidth
- rcxdude 8mo agoDepends on the bandwidth.
- Quppi 8mo agoFrom testing, it seems to require me to press my wrists quite hard against the macbook to get a somewhat accurate reading on the heartbeat. Non the less a cool project and I wasn't even aware my macbook has an accelerometer.
- gavinsyancey 8mo agoThe laptop also contains a normal microphone. You can't access this without root; if you have that you have permissions to access the real microphone.
- 8mo ago
- LoganDark 8mo agoI wonder if this sensor is used for Vision Pro display mirroring.
- 1e1a 8mo agoI think it's used for the motion sickness reducing feature in MacOS Tahoe that puts a bunch of dots on your screen that react to motion.
- 1e1a 8mo agoI've been wondering about this for a while, glad someone's finally managed to access it.
- 1e1a 8mo agoOn my M4 14-inch MacBook Pro, it looks like there are two accelerometers: One with {"DeviceUsagePage"=0xff00,"DeviceUsage"=3}, and one with {"DeviceUsagePage"=0xff00,"DeviceUsage"=9} - They both identify as Bosch BMI286
- 1e1a 8mo agoAh, after some testing, it looks like these both refer to the same IMU, DeviceUsage=3 is for the accelerometer and DeviceUsage=9 is for the gyroscope. The serial number is also the same for both.
- deleted 8mo ago[deleted]
- 47282847 8mo agoI would like an app to lock my screen on sudden movement; optionally disable TouchID for next login.
- ohyoutravel 8mo ago[flagged]
- 47282847 8mo agoAre you implying that it is paranoid and irrational regardless of circumstance to want this? Sorry to disappoint. I’m working in the human rights space, with dozens of real world experiences by people I work with. I got raided once myself. They were unable to locate any computer on my premises. They however took my phone and a couple of encrypted hard drives for forensic analysis. They asked for the device PIN, which I did not provide. A court later ruled the raid and seizure and temporary confinement illegal. I did not reuse the returned phone. They didn’t pay for the replacement, or the lawyer.
- ohyoutravel 8mo agoYes that was my implication, but I see based on your comment you have real concerns! My apologies for the implication.
- hansum 8mo agothis is the best internet argument
- flemhans 8mo agoI remember that existed way back then. And MacSaber... MacSaber!!!
- thenthenthen 8mo agoThis is so cool thank you!
- renecito 8mo ago"hidden", checks API: https://developer.apple.com/documentation/coremotion/cmdevicemotion https://developer.apple.com/documentation/coremotion/cmdevic... and there is Mac Catalyst (iOS on Mac) and Mac support. what am I missing ? that this uses a raw stream ?
- thekevintang 8mo agoHere’s a tilt sim for Mac - https://github.com/NSEvent/tilt-sim-experiment https://github.com/NSEvent/tilt-sim-experiment
- olvvier 8mo agoauthor here, quick update: the sensor code is now a standalone pip package pip install macimu from macimu import IMU with IMU() as imu: print(imu.latest_accel()) # Sample(x, y, z) in g print(imu.latest_gyro()) # Sample(x, y, z) in deg/s requires sudo. details: https://github.com/olvvier/apple-silicon-accelerometer https://github.com/olvvier/apple-silicon-accelerometer