Ask HN: Logging Mac Trackpad Data?

[desertraven]

Hi guys,

I'm interested in learning more about trackpads, with a view to add one to an electronics project. Rather than buying a trackpad and hooking it up to an arduino to see if it meets requirements, I figured I'd use the Mac trackpad I already have.

I really just want to see what the shape of the incoming data is, pipe it to a file, and process it later on (at least that's what I'll be doing in my electronics project).

Is it possible to do this with a mac trackpad? Just log the incoming data (time-series coordinates I imagine), throw it in a file.

Thanks!

[Someone]

For low-level stuff, Apple used to have a developer tool named “USB Prober” for logging USB Traffic (https://developer.apple.com/download/all/?q=IOUSB), but that seems to have been abandoned.

Google tells me you can use WireShark to capture packets (https://developer.apple.com/forums/thread/95380) after disabling system integrity protection (https://developer.apple.com/forums/thread/124875)

I wouldn’t know whether that works today. Also, it wouldn’t be “time-series coordinates”, but that information would be in the data captured.

[undershirt]

I’m fairly new to macOS development, but I’ve been messing with this a lot lately. Here’s my Swift project[1] for showing macOS trackpad data, which you might be able to adapt to your needs.

[1] https://github.com/shaunlebron/macos-trackpad-demo