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new 0.6.7 | Oct 6, 2024 |
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0.6.6 | Nov 15, 2023 |
0.6.4 | Oct 11, 2023 |
0.5.3 | Oct 12, 2022 |
0.1.0 | Jun 9, 2022 |
#95 in Hardware support
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1.5MB
22K
SLoC
Bluest — Cross-platform Bluetooth LE crate for Rust
Bluest is a cross-platform Bluetooth Low Energy (BLE) library for Rust. It currently supports Windows (version 10 and later), MacOS/iOS, and Linux. Android support is planned.
The goal of Bluest is to create a thin abstraction on top of the platform-specific Bluetooth APIs in order to provide safe, cross-platform access to Bluetooth LE devices. The crate currently supports the GAP Central and GATT Client roles. Peripheral and Server roles are not supported.
Usage
let adapter = Adapter::default().await.ok_or("Bluetooth adapter not found")?;
adapter.wait_available().await?;
println!("starting scan");
let mut scan = adapter.scan(&[]).await?;
println!("scan started");
while let Some(discovered_device) = scan.next().await {
println!(
"{}{}: {:?}",
discovered_device.device.name().as_deref().unwrap_or("(unknown)"),
discovered_device
.rssi
.map(|x| format!(" ({}dBm)", x))
.unwrap_or_default(),
discovered_device.adv_data.services
);
}
Overview
The primary functions provided by Bluest are:
- Device discovery:
- Scanning for devices and receiving advertisements
- Finding connected devices
- Opening previously found devices
- Connecting to discovered devices
- Pairing with devices
- Accessing remote GATT services:
- Discovering device services
- Discovering service characteristics
- Discovering characteristic descriptors
- Read, write (including write without response), and notify/indicate operations on remote characteristics
- Read and write operations on characteristic descriptors
Asynchronous runtimes
On non-linux platforms, Bluest should work with any asynchronous runtime. On
linux the underlying bluer
crate requires the Tokio runtime and Bluest makes
use of Tokio's block_in_place
API (which requires Tokio's multi-threaded
runtime) to make a few methods synchronous. Linux-only asynchronous versions of
those methods are also provided, which should be preferred in platform-specific
code.
Platform specifics
Because Bluest aims to provide a thin abstraction over the platform-specific
APIs, the available APIs represent the lowest common denominator of APIs among
the supported platforms. For example, CoreBluetooth never exposes the Bluetooth
address of devices to applications, therefore there is no method on Device
for
retrieving an address or even any Bluetooth address struct in the crate.
Most Bluest APIs should behave consistently across all supported platforms. Those APIs with significant differences in behavior are summarized in the table below.
Method | MacOS/iOS | Windows | Linux |
---|---|---|---|
Adapter::connect_device |
✅ | ✨ | ✅ |
Adapter::disconnect_device |
✅ | ✨ | ✅ |
Device::name |
✅ | ✅ | ⌛️ |
Device::is_paired |
❌ | ✅ | ✅ |
Device::pair |
✨ | ✅ | ✅ |
Device::pair_with_agent |
✨ | ✅ | ✅ |
Device::unpair |
❌ | ✅ | ✅ |
Device::rssi |
✅ | ❌ | ❌ |
Service::uuid |
✅ | ✅ | ⌛️ |
Service::is_primary |
✅ | ❌ | ✅ |
Characteristic::uuid |
✅ | ✅ | ⌛️ |
Characteristic::max_write_len |
✅ | ✅ | ⌛️ |
Descriptor::uuid |
✅ | ✅ | ⌛️ |
✅ = supported
✨ = managed automatically by the OS, this method is a no-op
⌛️ = the underlying API is async so this method uses Tokio's block_in_place
API internally
❌ = returns a NotSupported
error
Also, the errors returned by APIs in a given situation may not be consistent
from platform to platform. For example, Linux's bluez API does not return the
underlying Bluetooth protocol error in a useful way, whereas the other platforms
do. Where it is possible to return a meaningful error, Bluest will attempt to do
so. In other cases, Bluest may return an error with a kind
of
Other
and you would need to look at the
platform-specific source
of the error for more
information.
Feature flags
The serde
feature is available to enable serializing/deserializing device
identifiers.
Examples
Examples demonstrating basic usage are available in the examples folder.
Refer to the API documentation for more details.
Dependencies
~0.8–41MB
~640K SLoC