4 ms·

>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 ago
The 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 ago
  Aaackshually, 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 ago
    I think there's some sort of motion sickness reducing feature in MacOS Tahoe which would require an accelerometer.
  - lelandfe 8mo ago
    In 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 :)
- nerdsniper 8mo ago
  Given that current drives don't have moving parts, what function is this serving today?
  - juggerl6 8mo ago
    [dead]
    - nerdsniper 8mo ago
      Has anyone reported this happening?
      - xattt 8mo ago
        People who knew what they did aren’t going to go online and say that they tried to return a dropped device.
saagarjha 8mo ago
> the sensor lives under AppleSPUHIDDevice in the iokit registry, on vendor usage page 0xFF00, usage 3. the driver is AppleSPUHIDDriver which is part of the sensor processing unit.
argsnd 8mo ago
Apple has a motion sickness mitigation feature that displays dots on your screen that move based on physical motion, so it’s fairly well known that the accelerometer exists.
- mschuster91 8mo ago
  That's for iOS devices though
  - angulardragon03 8mo ago
    It’s also for macOS
  - nom 8mo ago
    No.
  - Someone 8mo ago
    https://support.apple.com/en-om/guide/mac-help/mchla3c4f1da/mac https://support.apple.com/en-om/guide/mac-help/mchla3c4f1da/...: “Vehicle Motion Cues Vehicle Motion Cues may help reduce vehicle motion sickness while using a Mac and riding as a passenger in a car or other on-road vehicle. To customize Vehicle Motion cues, click Customize Appearance, then set any of the following options: - Pattern: Select Regular for a stable and predictable pattern of onscreen dots, or Dynamic for a more engaging visual experience. - Color: Select a color of onscreen dots. Color saturation will automatically adjust to maintain contrast with the content behind each dot. - Larger dots: Turn on Large dots to increase the size of the dots that appear onscreen. - More dots: Turn on More dots to increase the number of dots that appear onscreen. Note: This option is available on Mac laptop computers. It’s not available on MacBook Air (M1) or 13-inch MacBook Pro (M1) or earlier.”

rustyhancock 8mo ago

The 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 ago
Aaackshually, 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 ago
  I think there's some sort of motion sickness reducing feature in MacOS Tahoe which would require an accelerometer.
- lelandfe 8mo ago
  In 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 :)
nerdsniper 8mo ago
Given that current drives don't have moving parts, what function is this serving today?
- juggerl6 8mo ago
  [dead]
  - nerdsniper 8mo ago
    Has anyone reported this happening?
    - xattt 8mo ago
      People who knew what they did aren’t going to go online and say that they tried to return a dropped device.

saagarjha 8mo ago

> the sensor lives under AppleSPUHIDDevice in the iokit registry, on vendor usage page 0xFF00, usage 3. the driver is AppleSPUHIDDriver which is part of the sensor processing unit.

argsnd 8mo ago

Apple has a motion sickness mitigation feature that displays dots on your screen that move based on physical motion, so it’s fairly well known that the accelerometer exists.

mschuster91 8mo ago
That's for iOS devices though
- angulardragon03 8mo ago
  It’s also for macOS
- nom 8mo ago
  No.
- Someone 8mo ago
  https://support.apple.com/en-om/guide/mac-help/mchla3c4f1da/mac https://support.apple.com/en-om/guide/mac-help/mchla3c4f1da/...: “Vehicle Motion Cues Vehicle Motion Cues may help reduce vehicle motion sickness while using a Mac and riding as a passenger in a car or other on-road vehicle. To customize Vehicle Motion cues, click Customize Appearance, then set any of the following options: - Pattern: Select Regular for a stable and predictable pattern of onscreen dots, or Dynamic for a more engaging visual experience. - Color: Select a color of onscreen dots. Color saturation will automatically adjust to maintain contrast with the content behind each dot. - Larger dots: Turn on Large dots to increase the size of the dots that appear onscreen. - More dots: Turn on More dots to increase the number of dots that appear onscreen. Note: This option is available on Mac laptop computers. It’s not available on MacBook Air (M1) or 13-inch MacBook Pro (M1) or earlier.”