#bluetooth #ble #bluez #uwp #corebluetooth

btleplug

A Cross-Platform Rust Bluetooth Low Energy (BLE) GATT library

15 unstable releases (4 breaking)

0.7.2 Apr 4, 2021
0.7.1 Mar 1, 2021
0.6.0 Feb 5, 2021
0.5.4 Oct 7, 2020
0.4.1 Mar 17, 2020

#17 in Hardware support

Download history 245/week @ 2020-12-29 176/week @ 2021-01-05 129/week @ 2021-01-12 205/week @ 2021-01-19 123/week @ 2021-01-26 252/week @ 2021-02-02 158/week @ 2021-02-09 208/week @ 2021-02-16 164/week @ 2021-02-23 173/week @ 2021-03-02 130/week @ 2021-03-09 112/week @ 2021-03-16 152/week @ 2021-03-23 126/week @ 2021-03-30 152/week @ 2021-04-06 154/week @ 2021-04-13

682 downloads per month
Used in 6 crates (5 directly)

MIT/Apache-2.0/BSD-3-Clause

245KB
4.5K SLoC

btleplug

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btleplug is a Rust BLE library, support Windows 10, macOS, Linux, and possibly iOS. It is currently made up of parts of other abandoned projects with a goal of building a fully cross platform proof of concept.

Our goal is the bring in some of the outstanding PRs from other projects, expand the platform support, and possibly make the API surface more ergonomic for being a truly cross-platform library.

Oh and async might happen to because why not.

btleplug is meant to be host/central mode only. If you are interested in peripheral BTLE (i.e. acting like a Bluetooth LE device instead of connecting to one), check out bluster.

This library DOES NOT SUPPORT BLUETOOTH 2/CLASSIC. There are no plans to add BT2/Classic support.

A Whole New World of Bluetooth Copypasta

At the moment, and probably for the foreseeable future, very little of what is included in BTLEPlug will be new or original code. The goal for the moment is to get a single library that works everywhere, then start bending the API surface around the different platform requirements once we can at least bring up adapters and start finding devices everywhere.

The libraries we're forking include:

  • rumble
    • Started with a bluez implementation, but became our main repo fork basis because it was the only library to have even a partial UWP implementation. API surface was built to reflect bluez 1:1, which makes cross-platform ergonomics a bit difficult, but it's a model we can start with for now, and change later.
    • Project seems to be abandoned.
  • blurmac (alternative repo?)
    • Complete-ish WebBluetooth BTLE implementation for MacOS/iOS CoreBluetooth, originally built for use in Mozilla's Servo browser. Makes some assumptions about being embedded in Servo. For instance, the base library doesn't spin up any event queues because it expects to be embedded in a Cocoa application with a main event queue.
    • Project seems to be abandoned.
  • blurdroid (alternative repo?)
    • Same as blurmac, developed for Servo, but handles Android 4.4+'s BTLE stack via JNI calls.
    • Project seems to be abandoned.

In addition, here's the libraries we'll be referencing/cribbing from for updating APIs.

  • bluster
    • BTLE Peripheral library. Uses async rust via Tokio.
    • Active project
  • noble-mac
    • Noble (node BTLE module) implementation for MacOS via CoreBluetooth. Built in Obj-C and C.
    • Active project
  • noble-uwp
    • Noble (node BTLE module) implemenation for Windows UWP. Built in C++.
    • Active project

Development Goals

The issues in this repo reflect the development goals of the project. First and foremost is getting as many platforms as possible up and running enough to support our main usage of this library. For the time being we'll most likely keep the rumble API surface model, just so we don't have to change large portions of the code as we go.

Beyond that, some of our other goals are:

  • Make API more ergonomic to support multiple bluetooth APIs (not just focusing on bluez)
  • Add FFI so this library can be used from C (and maybe C++ using cxx.
  • Provide both async and sync versions of as many APIs as possible (once again, depending on platform API capabilities)
  • Possibly create a WASM compatible layer using wasm-bindgen and WebBluetooth

Platform Status

  • Linux / Windows / macOS
    • Device enumeration and characteristic/services implemented, works ok.
    • Please file bugs and missing features if you find them.
  • iOS
    • Trying to figure out if the macOS implementation will translate, minus things having to do with background processing. Might just work already?
    • Tracking issue here
    • Please file bugs and missing features if you find them.
  • Android
    • A rust android library exists (the aforementioned blurdroid), but getting a PoC up and tested is going to require some work. Definitely looking for help.
    • Tracking issue here.
    • Please hold off on filing more issues until base implementation is landed.
  • WASM/WebBluetooth
    • WebBluetooth has been added to wasm-bindgen's web-sys by @qdot, and a full implementation has been done in other libraries that could easily be ported here. This is now definitely in the works, once the new API surface is solidified.
    • Tracking issue here
    • Please hold off on filing more issues until base implementation is landed.

Platform Feature Table

  • X: Completed and released
  • O: In development
  • Blank: Not started
Feature Windows MacOS Linux
Bring Up Adapter X X X
Handle Multiple Adapters X
Discover Devices X X X
└ Discover Services O
└ Discover Name X X X
└ Discover Manufacturer Data X X
GATT Server Connect X X X
GATT Server Connect Event X X X
GATT Server Disconnect X X X
GATT Server Disconnect Event X X X
Write to Characteristic (Sync) X X X
Write to Characteristic (Async) X
Read from Characteristic (Sync) X X X
Read from Characteristic (Async) X
Subscribe to Characteristic (Sync) X X X
Subscribe to Characteristic (Async)
Unsubscribe from Characteristic (Sync) X X
Unsubscribe from Characteristic (Async)
Get Characteristic Notification Event X X X
Read Descriptor (Sync)
Read Descriptor (Async)
Write Descriptor (Sync)
Write Descriptor (Async)

Library Features

Serialization/Deserialization

To enable implementation of serde's Serialize and Deserialize across some common types in the api module, use the serde feature.

[dependencies]
btleplug = { version = "0.4", features = ["serde"] }

Old rumble README Content

Rumble

Rumble is a Bluetooth Low Energy (BLE) central module library for Rust. Currently only Linux (with the BlueZ bluetooth library) is supported, although other operating systems may be supported in the future. Rumble interfaces with BlueZ using its socket interface rather than DBus. This offers much more control and reliability over the DBus interface, and does not require running BlueZ in experimental mode for BLE.

As of version 0.2, the API is becoming more stable and the library itself more useful. You should still expect to encounter bugs, limitations, and odd behaviors. Pull requests (and wireshark traces) welcome!

Usage

An example of how to use the library to control some BLE smart lights:

extern crate rumble;
extern crate rand;

use std::thread;
use std::time::Duration;
use rand::{Rng, thread_rng};
use rumble::bluez::manager::Manager;
use rumble::api::{Central, Peripheral, WriteType, UUID};

pub fn main() {
    let manager = Manager::new().unwrap();

    // get the first bluetooth adapter
    let adapters = manager.adapters().unwrap();
    let mut adapter = adapters.into_iter().nth(0).unwrap();

    // reset the adapter -- clears out any errant state
    adapter = manager.down(&adapter).unwrap();
    adapter = manager.up(&adapter).unwrap();

    // connect to the adapter
    let central = adapter.connect().unwrap();

    // start scanning for devices
    central.start_scan().unwrap();
    // instead of waiting, you can use central.on_event to be notified of
    // new devices
    thread::sleep(Duration::from_secs(2));

    // find the device we're interested in
    let light = central.peripherals().into_iter()
        .find(|p| p.properties().local_name.iter()
            .any(|name| name.contains("LEDBlue"))).unwrap();

    // connect to the device
    light.connect().unwrap();

    // discover characteristics
    light.discover_characteristics().unwrap();

    // find the characteristic we want
    let chars = light.characteristics();
    let cmd_char = chars.iter().find(|c| c.uuid == UUID::B16(0xFFE9)).unwrap();

    // dance party
    let mut rng = thread_rng();
    for _ in 0..20 {
        let color_cmd = vec![0x56, rng.gen(), rng.gen(), rng.gen(), 0x00, 0xF0, 0xAA];
        light.write(&cmd_char, &color_cmd, WriteType::WithoutResponse).unwrap();
        thread::sleep(Duration::from_millis(200));
    }
}

Above code use is just waits for 2 seconds to see whatever device it can discover. This code example shows how to use event-driven discovery:

let (event_sender, event_receiver) = channel(256);
// Add ourselves to the central event handler output now, so we don't
// have to carry around the Central object. We'll be using this in
// connect anyways.
let on_event = move |event: CentralEvent| match event {
    CentralEvent::DeviceDiscovered(bd_addr) => {
        println!("DeviceDiscovered: {:?}", bd_addr);
        let s = event_sender.clone();
        let e = event.clone();
        task::spawn(async move {
            s.send(e).await;
        });
    }
    CentralEvent::DeviceConnected(bd_addr) => {
        println!("DeviceConnected: {:?}", bd_addr);
        let s = event_sender.clone();
        let e = event.clone();
        task::spawn(async move {
            s.send(e).await;
        });
    }
    CentralEvent::DeviceDisconnected(bd_addr) => {
        println!("DeviceDisconnected: {:?}", bd_addr);
        let s = event_sender.clone();
        let e = event.clone();
        task::spawn(async move {
            s.send(e).await;
        });
    }
    _ => {}
};

central.on_event(Box::new(on_event));

// Infinite loop otherwise the application will quit
loop {};

License

BTLEPlug is covered under a BSD 3-Clause License, with some parts from Rumble/Blurmac covered under MIT/Apache dual license, and BSD 3-Clause licenses, respectively. See LICENSE.md for more info and copyright information.

Dependencies

~1.4–5.5MB
~83K SLoC