Reading the undocumented MEMS accelerometer on Apple Silicon MacBooks via iokit

Re:Reading the undocumented MEMS accelerometer on Apple Sili... by JSR_FDED on Friday February 20, 2026 @03:27AM (#47085256)

If 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.

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Re:Reading the undocumented MEMS accelerometer on Apple Sili... by pbhjpbhj on Friday February 20, 2026 @03:45AM (#47085369)

If it's sensitive enough to read a heart beat, then surely it can be used as a covert microphone?

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Re:Reading the undocumented MEMS accelerometer on Apple Sili... by rcxdude on Friday February 20, 2026 @04:13AM (#47085554)

Depends on the bandwidth.

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Re:Reading the undocumented MEMS accelerometer on Apple Sili... by rcxdude on Friday February 20, 2026 @04:13AM (#47085550)

depends on the bandwidth

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Re:Reading the undocumented MEMS accelerometer on Apple Sili... by Quppi on Friday February 20, 2026 @06:02AM (#47086418)

From 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.

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Re:Reading the undocumented MEMS accelerometer on Apple Sili... by gavinsyancey on Friday February 20, 2026 @06:43AM (#47086779)

The 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.

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Re:Reading the undocumented MEMS accelerometer on Apple Sili... by nottorp on Friday February 20, 2026 @07:19AM (#47087105)

... but think how much "engagement" a "security expert" would get out of this!

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Re:Reading the undocumented MEMS accelerometer on Apple Sili... by 1e1a on Sunday February 22, 2026 @04:21AM (#47109598)

I can access the IMU without root on my M4 mac running Sequoia

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Re:Reading the undocumented MEMS accelerometer on Apple Sili... by 1e1a on Sunday February 22, 2026 @04:18AM (#47109588)

The sample rate is only ~800hz (probably very difficult/impossible to increase)

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Re:Reading the undocumented MEMS accelerometer on Apple Sili... by pbhjpbhj on Tuesday February 24, 2026 @03:36AM (#47134478)

The fundamental frequencies of voice are below half that, I think that means you can use it to determine what is said writing it's sensitivity range.

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