rust_lum/src/bluetooth.rs
2022-01-31 17:05:59 +01:00

111 lines
3.4 KiB
Rust

use bluer::gatt::remote::Characteristic;
use bluer::{Adapter, AdapterEvent, Address, Device, Result, Uuid};
use futures::{pin_mut, StreamExt};
use std::collections::HashSet;
use std::time::Duration;
use tokio::sync::mpsc;
// const CONNECT_RETRIES: u8 = 3;
// const SERVICE_UUID: bluer::Uuid = bluer::Uuid::from_u128(0xadaf0900c33242a893bd25e905756cb8);
// const PIXEL_DATA_UUID: bluer::Uuid = bluer::Uuid::from_u128(0xadaf0903c33242a893bd25e905756cb8);
pub(crate) async fn create_session() -> Result<Adapter> {
let session = bluer::Session::new().await?;
let adapter_names = session.adapter_names().await?;
let adapter_name = adapter_names.first().expect("no Bluetooth adapter found");
let adapter = session.adapter(adapter_name)?;
adapter.set_powered(true).await?;
Ok(adapter)
}
async fn has_service(device: &Device, uuid: &Uuid) -> Result<bool> {
let uuids = device.uuids().await?.unwrap_or_default();
if uuids.contains(uuid) {
return Ok(true);
}
Ok(false)
}
async fn bluetooth_scan(tx: mpsc::Sender<Device>, adapter: Adapter, uuid: Uuid) -> Result<()> {
println!("start bluetooth scan");
let discover = adapter.discover_devices().await?;
let mut already_scanned: HashSet<Address> = HashSet::new();
pin_mut!(discover);
while let Some(evt) = discover.next().await {
match evt {
AdapterEvent::DeviceAdded(addr) => {
if already_scanned.contains(&addr) {
continue;
}
already_scanned.insert(addr);
let device = adapter.device(addr)?;
match has_service(&device, &uuid).await {
Ok(service_found) => {
if service_found {
tx.send(device).await.unwrap();
println!("found service in device {}", addr);
}
}
Err(_) => continue,
}
}
_ => {}
}
}
Ok(())
}
pub(crate) async fn scan_devices(adapter: Adapter, uuid: Uuid) -> Vec<Device> {
let (tx, mut rx) = mpsc::channel(4);
let timeout = tokio::time::timeout(Duration::from_secs(30), bluetooth_scan(tx, adapter, uuid));
let scan = tokio::spawn(timeout);
let mut devices: Vec<Device> = Vec::new();
while let Some(device) = rx.recv().await {
devices.push(device);
if devices.len() >= 2 {
drop(scan);
break;
}
}
devices
}
pub async fn connect(device: &Device, retries: u8) -> bluer::Result<()> {
if device.is_connected().await? {
return Ok(());
}
for i in 0..retries {
match device.connect().await {
Ok(()) => return Ok(()),
Err(_) => {
println!("connection error ({}), retry…", i);
}
}
}
Err(bluer::Error {
kind: bluer::ErrorKind::ConnectionAttemptFailed,
message: "all attempts fail".parse().unwrap(),
})
}
pub async fn get_char(
device: &Device,
service_uuid: Uuid,
char_uuid: Uuid,
) -> Result<Option<Characteristic>> {
for service in device.services().await? {
if service_uuid == service.uuid().await? {
for char in service.characteristics().await? {
if char_uuid == char.uuid().await? {
return Ok(Some(char));
}
}
}
}
Ok(None)
}