Crate hid_descriptor 

Tools for building USB HID report descriptors.

This is a utility for generating a binary USB HID report descriptor from Rust code. It can be used from build.rs so that the descriptor is generated at compile time, and the descriptor bytes can be included in the code, with no runtime cost.

Alternatively, you can edit one of the example binaries, and copy the resulting descriptor file into your project.

See Device Class Definition for Human Interface Devices for a detailed description of HID report descriptors.

Example

// `build.rs`
use hid_descriptor::*;
use hid_types::id::{IoFlags, KnownCollectionType, KnownUsagePage};
use hid_types::id::usage::{generic_desktop, keyboard_keypad};

fn main() {
    println!("cargo:rerun-if-changed=build.rs");
    let out_dir = PathBuf::from(std::env::var_os("OUT_DIR").unwrap());
    let descriptor_path = out_dir.join("descriptor.bin");
    println!("cargo:rerun-if-changed={}", descriptor_path.display());

    let bytes = [
        usage_page(KnownUsagePage::GenericDesktop),
        usage(generic_desktop::KnownUsage::Gamepad),
        collection(KnownCollectionType::Application),
        usage_page(KnownUsagePage::Button),
        usage_minimum(1u16),
        usage_maximum(8u16),
        logical_minimum(0),
        logical_maximum(1),
        report_size(1),
        report_count(8),
        input(IoFlags::data().variable()),
        end_collection(),
    ];
    write_to_file(bytes, descriptor_path).unwrap();
}

//! In your crate, compile in the descriptor bytes.
static GAMEPAD_DESCRIPTOR: &[u8] =
    include_bytes!(concat!(env!("OUT_DIR"), "/descriptor.bin"));

Re-exports

pub use hid_types;

Traits

EncodeItem

A trait for items that can be encoded into the HID report descriptor binary format.

Functions

collection

Create a Collection.

concatenate_bytes

Concatenate a bunch of descriptor bytes into one iterator.

designator_index

Create a Designator Index.

designator_maximum

Create a Designator Maximum.

designator_minimum

Create a Designator Minimum.

encode_items

Encode a sequence of items into a binary HID report descriptor.

end_collection

Create an End Collection.

extended_usage

Create an extended Usage value with a Usage Page attached.

feature

Create a Feature item.

input

Create an Input item.

logical_maximum

Create a Logical Maximum.

logical_minimum

Create a Logical Minimum.

output

Create an Output item.

physical_maximum

Create a Physical Maximum.

physical_minimum

Create a Physical Minimum.

pop

Create a Pop.

push

Create a Push.

report_count

Create a Report Count value.

report_id

Create a Report ID.

report_size

Create a Report Size value.

string_

Create a Delimiter.

string_index

Create a String Index.

string_maximum

Create a String Maximum.

string_minimum

Create a String Minimum.

unit

Create a Unit.

unit_exponent

Create a Unit Exponent.

usage

Create a Usage value.

usage_maximum

Create a Usage Maximum value.

usage_minimum

Create a Usage Minimum value.

usage_page

Create a Usage Page.

write_to_file

Write a binary encoded descriptor to a file.

Type Aliases

DescriptorBytes

A variable-length short chunk of descriptor bytes.