Serial

@inject Bit.Butil.Serial serial

var supported = await serial.IsSupported();

private SerialPort? _port;

_port = await serial.RequestPort();
// or narrowed to one adapter:
_port = await serial.RequestPort(new SerialPortFilter { UsbVendorId = 0x2341 });

var granted = await serial.GetPorts();

@code {
    // The port from RequestPort above - a grant is per port, and this is the way back to one the
    // user has already chosen.
    private SerialPort? _port;

    private async Task OpenAndClose()
    {
        await _port!.Open(new SerialOptions
        {
            BaudRate = 115200,
            DataBits = 8,
            StopBits = 1,
            Parity = SerialParity.None,
            FlowControl = SerialFlowControl.None
        });

        await _port.Close();
    }
}

@implements IAsyncDisposable

@code {
    private SerialPort? _port;              // from RequestPort, and opened
    private ButilSubscription? _reading;

    private async Task Talk()
    {
        _reading = await _port!.SubscribeData(
            onData: bytes => Console.WriteLine(Encoding.UTF8.GetString(bytes)),
            onError: message => Console.WriteLine(message));

        await _port.WriteText("AT\r\n");
        await _port.Write([0x01, 0x02]);
    }

    // The subscription holds the port's readable stream locked; nothing else can read it until
    // this goes away.
    public async ValueTask DisposeAsync()
    {
        if (_reading is not null) await _reading.DisposeAsync();
    }
}

@code {
    private SerialPort? _port;   // from RequestPort, and opened

    private async Task Signals()
    {
        var signals = await _port!.GetSignals();
        // signals.ClearToSend, DataSetReady, DataCarrierDetect, RingIndicator

        await _port.SetSignals(dataTerminalReady: true);
    }
}

await using var watch = await serial.SubscribeConnection(
    onConnected: port => Console.WriteLine($"+ {port.Id}"),
    onDisconnected: port => Console.WriteLine($"- {port.Id}"));

@code {
    private SerialPort? _port;   // from RequestPort

    // Drops the grant, so GetPorts stops returning it and the picker has to be shown again.
    private async Task Revoke()
    {
        var revoked = await _port!.Forget();
        _port = null;
    }
}