MediusInstall

Connection

Device is the handle. Opening one finds the box, runs the handshake, and starts the background threads in one call. Dropping the last handle releases the port.

See also: choosing a port, threading, and keepalive & teardown.

Open a deviceAuto-detect, or a known path

fn Device::open(path: impl AsRef<Path>) -> Result<Device>

Blocks

fn Device::find() -> Result<Device>

Blocks

fn find_medius() -> Vec<PortInfo>

No round-trip

open and find block on the handshake. Auto-detect matches the USB identity of the WCH CH343 bridge in every box (vid 0x1A86, pid 0x55D3).

FUNCTIONS
NameDescription
openOpens a serial path (Linux /dev/ttyACM0, Windows COM3).
findOpens the first matching port, or returns Error::NotFound.
find_mediusLists every match as a PortInfo without opening one.
EXAMPLE
use medius::Device;

// auto-detect the box:
let dev = Device::find()?;

// or open a known path:
let dev = Device::open("/dev/ttyACM0")?;

Zero configThree read-only values

Two defaults bound the QUERY wait and the keepalive timer.

ConstantValue
DEFAULT_QUERY_TIMEOUT1 s
DEFAULT_KEEPALIVE_CADENCE500 ms
PROTO_VER9

PROTO_VER is the control protocol version this build speaks. A box reporting anything else is refused at the handshake.

EXAMPLE
use medius::{DEFAULT_QUERY_TIMEOUT, DEFAULT_KEEPALIVE_CADENCE, PROTO_VER};

println!("query timeout:     {:?}", DEFAULT_QUERY_TIMEOUT);   // 1s
println!("keepalive cadence: {:?}", DEFAULT_KEEPALIVE_CADENCE); // 500ms
println!("speaks protocol:   {}", PROTO_VER);                   // 9

Async deviceSame link, awaitable queries

fn AsyncDevice::open(path: impl AsRef<Path>) -> Result<AsyncDevice>

Blocks

fn AsyncDevice::find() -> Result<AsyncDevice>

Blocks

fn into_async(self) -> AsyncDevice

No round-trip

fn into_inner(self) -> Device

No round-trip

Behind the async feature, AsyncDevice makes the queries futures. Fire-and-forget calls stay synchronous.

cargo add medius --features async
EXAMPLE
use futures::executor::block_on;
use medius::AsyncDevice;

// find and open as async:
let dev = AsyncDevice::find()?;
let version = block_on(dev.query_version())?; // awaits the reply
dev.move_rel(10, 0)?;                          // fire-and-forget, stays sync

// or open a known path:
let dev = AsyncDevice::open("/dev/ttyACM0")?;