# bevy_serial

`bevy_serial` is a plugin to add non-blocking serial communication to bevy. This plugin is based on [`mio-serial`](https://github.com/berkowski/mio-serial) that can realize non-blocking high-performance I/O.

Reading and writing from/to serial port is realized via bevy's event system. Each serial port is handled via port name or a unique label you choose. These event handlers are added to the following stage to minimize the frame delay.

- Reading: `PreUpdate`
- Writing: `PostUpdate`

## Usage

### Simple Example

Here is a simple example:

```rust
use bevy::prelude::*;
use bevy_serial::{SerialPlugin, SerialReadEvent, SerialWriteEvent};

// to write data to serial port periodically
#[derive(Resource)]
struct SerialWriteTimer(Timer);

const SERIAL_PORT: &str = "/dev/ttyUSB0";

fn main() {
    App::new()
        .add_plugins(MinimalPlugins)
        // simply specify port name and baud rate for `SerialPlugin`
        .add_plugins(SerialPlugin::new(SERIAL_PORT, 115200))
        // to write data to serial port periodically (every 1 second)
        .insert_resource(SerialWriteTimer(Timer::from_seconds(
            1.0,
            TimerMode::Repeating,
        )))
        // reading and writing from/to serial port is achieved via bevy's event system
        .add_systems(Update, read_serial)
        .add_systems(Update, write_serial)
        .run();
}

// reading event for serial port
fn read_serial(mut ev_serial: EventReader<SerialReadEvent>) {
    // you can get label of the port and received data buffer from `SerialReadEvent`
    for SerialReadEvent(label, buffer) in ev_serial.read() {
        let s = String::from_utf8(buffer.clone()).unwrap();
        println!("received packet from {label}: {s}");
    }
}

// writing event for serial port
fn write_serial(
    mut ev_serial: EventWriter<SerialWriteEvent>,
    mut timer: ResMut<SerialWriteTimer>,
    time: Res<Time>,
) {
    // write msg to serial port every 1 second not to flood serial port
    if timer.0.tick(time.delta()).just_finished() {
        // you can write to serial port via `SerialWriteEvent` with label and buffer to write
        let buffer = b"Hello, bevy!";
        ev_serial.send(SerialWriteEvent(SERIAL_PORT.to_string(), buffer.to_vec()));
    }
}
```

### Multiple Serial Ports with Additional Config

You can add multiple serial ports with additional config.

```rust
fn main() {
    App::new()
        .add_plugins(MinimalPlugins)
        // you can specify various configurations for multiple serial ports by this way
        .add_plugins(SerialPlugin::new_with_config(vec![SerialConfig {
            label: Some(SERIAL_LABEL.to_string()),
            port_name: SERIAL_PORT.to_string(),
            baud_rate: 115200,
            data_bits: DataBits::Eight,
            flow_control: FlowControl::None,
            parity: Parity::None,
            stop_bits: StopBits::One,
            timeout: Duration::from_millis(0),
            read_buffer_len: 2048,
            read_result_handler: Some(Arc::new(|label, result| {
                println!("Read result of {label}: {result:?}");
            })),
            write_result_handler: Some(Arc::new(|label, result| {
                println!("Write result of {label}: {result:?}");
            })),
        }]))
        // reading and writing from/to serial port is achieved via bevy's event system
        .add_systems(Update, read_serial)
        .add_systems(Update, write_serial)
        .run();
}
```

## Supported Versions

| bevy | bevy_serial |
| ---- | ----------- |
| 0.13 | 0.5, 0.6    |
| 0.12 | 0.4         |
| 0.11 | 0.3         |
| 0.6  | 0.2         |
| 0.5  | 0.1         |

## License

Dual-licensed under either

- MIT
- Apache 2.0