Simple HID OSX Application

Question

I am getting started with coding for HID devices. I got started with reading Apple documents and sample code. The code provided are terribly outdated that it doesn't even open in Xcode8.

Download Sample Code from Apple

I need help in finding a sample project / snippet for getting started with HID Services! Open a handle, read and write reports to device, Listen to reports generated by device in a run loop.

Answer 1

OS X/macOS's HID stack is called IOHIDFamily, and much of it is open source. This includes kernel and userspace components. You can find the code for various different OS X/macOS releases at

https://opensource.apple.com/

For 10.12.2 (latest code released at time of writing) you can browse the IOHIDFamily code here:

https://opensource.apple.com/source/IOHIDFamily/IOHIDFamily-870.31.1/

or download it as a zip file here:

https://opensource.apple.com/tarballs/IOHIDFamily/IOHIDFamily-870.31.1.tar.gz

The "tools" directory contains some userspace sample/test code which might help with what you're trying to do.

As for sample code not being updated, documentation being incomplete/outdated/missing, and provided code requiring a lot of effort to build: welcome to Mac systems & driver development. That's unfortunately how it is. I've been doing OS X kernel/driver work for 7 years, and while some things get easier with experience, downloading code from Apple and building it still feels like playing the lottery.

Answer 2

There are many ways to start your development:

1. Build from scratch with c lib: https://github.com/libusb/hidapi

2. Follow HID Driver documentation from Apple: https://developer.apple.com/documentation/hiddriverkit Resource reference:

• Communicate between Client and User: https://developer.apple.com/documentation/driverkit/communicating_between_a_driverkit_extension_and_a_client_app
• StylusHIDDriver: https://developer.apple.com/documentation/hiddriverkit/handling_stylus_input_from_a_human_interface_device

3. Reference to some of GitHub resource like: https://github.com/astarasikov/osxhidtouch

As I aware, seem number 2 is the best way to develop your driver. But number 3 also a great place to start your development.