Class SerialPortClient

SerialPort client class for serial communication in worker scripts. Provides methods to open, close, read, and write serial ports. Supports multiple simultaneous serial port connections. The port ID is automatically set to the path. Extends Emittery for event-based data handling.

Example

import { SerialPortClient } from 'ECB';

// Create a serial port instance with configuration
const port = new SerialPortClient({
  path: 'COM3',
  baudRate: 115200
});

// Open the port
await port.open();

console.log(port.id); // 'COM3'

// Handle incoming data using on('data')
port.on('data', (data) => {
  console.log('Received:', data.toString('hex'));
});

// Handle errors
port.on('error', (err) => {
  console.error('Error:', err.message);
});

// Handle close event
port.on('close', () => {
  console.log('Port closed');
});

// Write data
await port.write(Buffer.from([0x01, 0x02, 0x03]));

// Close when done
await port.close();

Hierarchy

default<{ close: undefined; data: Buffer; error: Error }>
- SerialPortClient

Index

Constructors

constructor

new SerialPortClient(options: SerialPortOptions): SerialPortClient
Creates a new SerialPortClient instance
Parameters
- options: SerialPortOptions
  Serial port configuration options
Returns SerialPortClient
Example
```
const port = new SerialPortClient({
  path: 'COM3',
  baudRate: 115200
});
```
Overrides Emittery<{ data: Buffer error: Error close: undefined }>.constructor

Properties

debug

debug: DebugOptions<{ close: undefined; data: Buffer; error: Error }>

Debugging options for the current instance.

`Static`isDebugEnabled

isDebugEnabled: boolean

Toggle debug mode for all instances.

Default: true if the DEBUG environment variable is set to emittery or *, otherwise false.

Example

import Emittery from 'emittery';

Emittery.isDebugEnabled = true;

const emitter1 = new Emittery({debug: {name: 'myEmitter1'}});
const emitter2 = new Emittery({debug: {name: 'myEmitter2'}});

emitter1.on('test', data => {
	// …
});

emitter2.on('otherTest', data => {
	// …
});

emitter1.emit('test');
//=> [16:43:20.417][emittery:subscribe][myEmitter1] Event Name: test
//	data: undefined

emitter2.emit('otherTest');
//=> [16:43:20.417][emittery:subscribe][myEmitter2] Event Name: otherTest
//	data: undefined

`Static` `Readonly`listenerAdded

listenerAdded: typeof listenerAdded

Fires when an event listener was added.

An object with listener and eventName (if on or off was used) is provided as event data.

Example

import Emittery from 'emittery';

const emitter = new Emittery();

emitter.on(Emittery.listenerAdded, ({listener, eventName}) => {
	console.log(listener);
	//=> data => {}

	console.log(eventName);
	//=> '🦄'
});

emitter.on('🦄', data => {
	// Handle data
});

`Static` `Readonly`listenerRemoved

listenerRemoved: typeof listenerRemoved

Fires when an event listener was removed.

An object with listener and eventName (if on or off was used) is provided as event data.

Example

import Emittery from 'emittery';

const emitter = new Emittery();

const off = emitter.on('🦄', data => {
	// Handle data
});

emitter.on(Emittery.listenerRemoved, ({listener, eventName}) => {
	console.log(listener);
	//=> data => {}

	console.log(eventName);
	//=> '🦄'
});

off();

Accessors

id

get id(): string
Get the unique identifier of this serial port instance (equals to path)

Returns string
The serial port ID (path)
Example
```
const port = new SerialPortClient({ path: 'COM3', baudRate: 115200 });
console.log(port.id); // 'COM3'
```

isOpen

get isOpen(): boolean

Check if the serial port is currently open

Returns boolean

True if the port is open, false otherwise

Example

const port = new SerialPortClient({ path: 'COM3', baudRate: 115200 });
console.log(port.isOpen); // false
await port.open();
console.log(port.isOpen); // true

Methods

anyEvent

anyEvent(): AsyncIterableIterator<
    [
        "data"
        | "error"
        | "close",
        undefined | Buffer<ArrayBufferLike> | Error,
    ],
>

Get an async iterator which buffers a tuple of an event name and data each time an event is emitted.

Call return() on the iterator to remove the subscription.

In the same way as for events, you can subscribe by using the for await statement.

Returns AsyncIterableIterator<
    [
        "data"
        | "error"
        | "close",
        undefined | Buffer<ArrayBufferLike> | Error,
    ],
>

Example

import Emittery from 'emittery';

const emitter = new Emittery();
const iterator = emitter.anyEvent();

emitter.emit('🦄', '🌈1'); // Buffered
emitter.emit('🌟', '🌈2'); // Buffered

iterator.next()
	.then(({value, done}) => {
		// done is false
		// value is ['🦄', '🌈1']
		return iterator.next();
	})
	.then(({value, done}) => {
		// done is false
		// value is ['🌟', '🌈2']
		// revoke subscription
		return iterator.return();
	})
	.then(({done}) => {
		// done is true
	});

bindMethods

bindMethods(
target: Record<string, unknown>,
methodNames?: readonly string[],
): void
Bind the given methodNames, or all Emittery methods if methodNames is not defined, into the target object.
Parameters
- target: Record<string, unknown>
- OptionalmethodNames: readonly string[]
Returns void
Example
```
import Emittery from 'emittery';

const object = {};

new Emittery().bindMethods(object);

object.emit('event');
```
Inherited from Emittery.bindMethods

clearListeners

clearListeners<Name extends "data" | "error" | "close">(
eventName?: Name | readonly Name[],
): void
Clear all event listeners on the instance.

If eventName is given, only the listeners for that event are cleared.
Type Parameters
- Name extends "data" | "error" | "close"
Parameters
- OptionaleventName: Name | readonly Name[]
Returns void
Inherited from Emittery.clearListeners

close

close(): Promise<void>
Close the serial port

Returns Promise<void>
Promise that resolves when the port is closed
Throws
Error if the port is not open
Example
```
const port = new SerialPortClient({ path: 'COM3', baudRate: 115200 });
await port.open();
// ... do some work ...
await port.close();
```

emit

emit<Name extends "close">(eventName: Name): Promise<void>
Trigger an event asynchronously, optionally with some data. Listeners are called in the order they were added, but executed concurrently.
Type Parameters
- Name extends "close"
Parameters
- eventName: Name
Returns Promise<void>
A promise that resolves when all the event listeners are done. Done meaning executed if synchronous or resolved when an async/promise-returning function. You usually wouldn't want to wait for this, but you could for example catch possible errors. If any of the listeners throw/reject, the returned promise will be rejected with the error, but the other listeners will not be affected.

Inherited from Emittery.emit
emit<Name extends "data" | "error" | "close">(
eventName: Name,
eventData: { close: undefined; data: Buffer; error: Error }[Name],
): Promise<void>
Trigger an event asynchronously, optionally with some data. Listeners are called in the order they were added, but executed concurrently.
Type Parameters
- Name extends "data" | "error" | "close"
Parameters
- eventName: Name
- eventData: { close: undefined; data: Buffer; error: Error }[Name]
Returns Promise<void>
A promise that resolves when all the event listeners are done. Done meaning executed if synchronous or resolved when an async/promise-returning function. You usually wouldn't want to wait for this, but you could for example catch possible errors. If any of the listeners throw/reject, the returned promise will be rejected with the error, but the other listeners will not be affected.

Inherited from Emittery.emit

emitSerial

emitSerial<Name extends "close">(eventName: Name): Promise<void>
Same as emit(), but it waits for each listener to resolve before triggering the next one. This can be useful if your events depend on each other. Although ideally they should not. Prefer emit() whenever possible.

If any of the listeners throw/reject, the returned promise will be rejected with the error and the remaining listeners will not be called.
Type Parameters
- Name extends "close"
Parameters
- eventName: Name
Returns Promise<void>
A promise that resolves when all the event listeners are done.

Inherited from Emittery.emitSerial
emitSerial<Name extends "data" | "error" | "close">(
eventName: Name,
eventData: { close: undefined; data: Buffer; error: Error }[Name],
): Promise<void>
Same as emit(), but it waits for each listener to resolve before triggering the next one. This can be useful if your events depend on each other. Although ideally they should not. Prefer emit() whenever possible.

If any of the listeners throw/reject, the returned promise will be rejected with the error and the remaining listeners will not be called.
Type Parameters
- Name extends "data" | "error" | "close"
Parameters
- eventName: Name
- eventData: { close: undefined; data: Buffer; error: Error }[Name]
Returns Promise<void>
A promise that resolves when all the event listeners are done.

Inherited from Emittery.emitSerial

events

events<Name extends "data" | "error" | "close">(
eventName: Name | readonly Name[],
): AsyncIterableIterator<
{ close: undefined; data: Buffer; error: Error }[Name],
>

Get an async iterator which buffers data each time an event is emitted.

Call return() on the iterator to remove the subscription.

Type Parameters

Name extends "data" | "error" | "close"

Parameters

eventName: Name | readonly Name[]

Returns AsyncIterableIterator<{ close: undefined; data: Buffer; error: Error }[Name]>

Example

import Emittery from 'emittery';

const emitter = new Emittery();
const iterator = emitter.events('🦄');

emitter.emit('🦄', '🌈1'); // Buffered
emitter.emit('🦄', '🌈2'); // Buffered

iterator
	.next()
	.then(({value, done}) => {
		// done === false
		// value === '🌈1'
		return iterator.next();
	})
	.then(({value, done}) => {
		// done === false
		// value === '🌈2'
		// Revoke subscription
		return iterator.return();
	})
	.then(({done}) => {
		// done === true
	});

In practice you would usually consume the events using the for await statement. In that case, to revoke the subscription simply break the loop.

Example

import Emittery from 'emittery';

const emitter = new Emittery();
const iterator = emitter.events('🦄');

emitter.emit('🦄', '🌈1'); // Buffered
emitter.emit('🦄', '🌈2'); // Buffered

// In an async context.
for await (const data of iterator) {
	if (data === '🌈2') {
		break; // Revoke the subscription when we see the value `🌈2`.
	}
}

It accepts multiple event names.

Example

import Emittery from 'emittery';

const emitter = new Emittery();
const iterator = emitter.events(['🦄', '🦊']);

emitter.emit('🦄', '🌈1'); // Buffered
emitter.emit('🦊', '🌈2'); // Buffered

iterator
	.next()
	.then(({value, done}) => {
		// done === false
		// value === '🌈1'
		return iterator.next();
	})
	.then(({value, done}) => {
		// done === false
		// value === '🌈2'
		// Revoke subscription
		return iterator.return();
	})
	.then(({done}) => {
		// done === true
	});

listenerCount

listenerCount<Name extends "data" | "error" | "close">(
eventName?: Name | readonly Name[],
): number
The number of listeners for the eventName or all events if not specified.
Type Parameters
- Name extends "data" | "error" | "close"
Parameters
- OptionaleventName: Name | readonly Name[]
Returns number
Inherited from Emittery.listenerCount

off

off<Name extends "data" | "error" | "close" | (keyof OmnipresentEventData)>(
    eventName: Name | readonly Name[],
    listener: (
        eventData: (
            { close: undefined; data: Buffer; error: Error } & OmnipresentEventData
        )[Name],
    ) => void | Promise<void>,
): void
Remove one or more event subscriptions.
Type Parameters
- Name extends "data" | "error" | "close" | (keyof OmnipresentEventData)
Parameters
- eventName: Name | readonly Name[]
- listener: (
      eventData: (
          { close: undefined; data: Buffer; error: Error } & OmnipresentEventData
      )[Name],
  ) => void | Promise<void>
Returns void
Example
```
import Emittery from 'emittery';

const emitter = new Emittery();

const listener = data => {
	console.log(data);
};

emitter.on(['🦄', '🐶', '🦊'], listener);
await emitter.emit('🦄', 'a');
await emitter.emit('🐶', 'b');
await emitter.emit('🦊', 'c');
emitter.off('🦄', listener);
emitter.off(['🐶', '🦊'], listener);
await emitter.emit('🦄', 'a'); // nothing happens
await emitter.emit('🐶', 'b'); // nothing happens
await emitter.emit('🦊', 'c'); // nothing happens
```
Inherited from Emittery.off

offAny

offAny(
    listener: (
        eventName: "data" | "error" | "close",
        eventData: undefined | Buffer<ArrayBufferLike> | Error,
    ) => void | Promise<void>,
): void
Remove an onAny subscription.
Parameters
- listener: (
  eventName: "data" | "error" | "close",
  eventData: undefined | Buffer<ArrayBufferLike> | Error,
  ) => void | Promise<void>
Returns void
Inherited from Emittery.offAny

on

on<Name extends "data" | "error" | "close" | (keyof OmnipresentEventData)>(
    eventName: Name | readonly Name[],
    listener: (
        eventData: (
            { close: undefined; data: Buffer; error: Error } & OmnipresentEventData
        )[Name],
    ) => void | Promise<void>,
    options?: { signal?: AbortSignal },
): UnsubscribeFunction
Subscribe to one or more events.

Using the same listener multiple times for the same event will result in only one method call per emitted event.
Type Parameters
- Name extends "data" | "error" | "close" | (keyof OmnipresentEventData)
Parameters
- eventName: Name | readonly Name[]
- listener: (
      eventData: (
          { close: undefined; data: Buffer; error: Error } & OmnipresentEventData
      )[Name],
  ) => void | Promise<void>
- Optionaloptions: { signal?: AbortSignal }
Returns UnsubscribeFunction
An unsubscribe method.
Example
```
import Emittery from 'emittery';

const emitter = new Emittery();

emitter.on('🦄', data => {
	console.log(data);
});

emitter.on(['🦄', '🐶'], data => {
	console.log(data);
});

emitter.emit('🦄', '🌈'); // log => '🌈' x2
emitter.emit('🐶', '🍖'); // log => '🍖'
```
Inherited from Emittery.on

onAny

onAny(
    listener: (
        eventName: "data" | "error" | "close",
        eventData: undefined | Buffer<ArrayBufferLike> | Error,
    ) => void | Promise<void>,
    options?: { signal?: AbortSignal },
): UnsubscribeFunction
Subscribe to be notified about any event.
Parameters
- listener: (
  eventName: "data" | "error" | "close",
  eventData: undefined | Buffer<ArrayBufferLike> | Error,
  ) => void | Promise<void>
- Optionaloptions: { signal?: AbortSignal }
Returns UnsubscribeFunction
A method to unsubscribe.

Inherited from Emittery.onAny

once

once<Name extends "data" | "error" | "close" | (keyof OmnipresentEventData)>(
    eventName: Name | readonly Name[],
    predicate?: (
        eventData: (
            { close: undefined; data: Buffer; error: Error } & OmnipresentEventData
        )[Name],
    ) => boolean,
): EmitteryOncePromise<
    (
        { close: undefined; data: Buffer; error: Error } & OmnipresentEventData
    )[Name],
>
Subscribe to one or more events only once. It will be unsubscribed after the first event that matches the predicate (if provided).
Type Parameters
- Name extends "data" | "error" | "close" | (keyof OmnipresentEventData)
Parameters
- eventName: Name | readonly Name[]
  The event name(s) to subscribe to.
- Optionalpredicate: (
      eventData: (
          { close: undefined; data: Buffer; error: Error } & OmnipresentEventData
      )[Name],
  ) => boolean
  Optional predicate function to filter event data. The event will only be emitted if the predicate returns true.
Returns EmitteryOncePromise<
    (
        { close: undefined; data: Buffer; error: Error } & OmnipresentEventData
    )[Name],
>
The promise of event data when eventName is emitted and predicate matches (if provided). This promise is extended with an off method.
Example
```
import Emittery from 'emittery';

const emitter = new Emittery();

emitter.once('🦄').then(data => {
	console.log(data);
	//=> '🌈'
});

emitter.once(['🦄', '🐶']).then(data => {
	console.log(data);
});

// With predicate
emitter.once('data', data => data.ok === true).then(data => {
	console.log(data);
	//=> {ok: true, value: 42}
});

emitter.emit('🦄', '🌈'); // Logs `🌈` twice
emitter.emit('🐶', '🍖'); // Nothing happens
emitter.emit('data', {ok: false}); // Nothing happens
emitter.emit('data', {ok: true, value: 42}); // Logs {ok: true, value: 42}
```
Inherited from Emittery.once

open

open(): Promise<void>

Open the serial port

Returns Promise<void>

Promise that resolves when the port is opened

Throws

Error if the port is already open or if opening fails

Example

// Basic usage
const port = new SerialPortClient({
  path: 'COM3',
  baudRate: 115200
});
await port.open();

// Full configuration
const port2 = new SerialPortClient({
  path: '/dev/ttyUSB0',
  baudRate: 9600,
  dataBits: 8,
  stopBits: 1,
  parity: 'none',
  rtscts: false,
  xon: false,
  xoff: false
});
await port2.open();

write

write(data: Buffer<ArrayBufferLike> | number[]): Promise<void>

Write data to the serial port

Parameters

data: Buffer<ArrayBufferLike> | number[]
Data to write (Buffer or array of bytes)

Returns Promise<void>

Promise that resolves when data is written and drained

Throws

Error if the port is not open

Example

const port = new SerialPortClient({ path: 'COM3', baudRate: 115200 });
await port.open();

// Write using Buffer
await port.write(Buffer.from('Hello'));

// Write using byte array
await port.write([0x01, 0x02, 0x03, 0x04]);

// Write hex string as buffer
await port.write(Buffer.from('48454C4C4F', 'hex'));

`Static`list

list(): Promise<SerialPortInfo[]>
List all available serial ports on the system

Returns Promise<SerialPortInfo[]>
Promise that resolves with array of port information
Example
```
const ports = await SerialPortClient.list();
for (const port of ports) {
  console.log(`${port.path} - ${port.friendlyName || 'Unknown'}`);
}
```

`Static`mixin

mixin(
emitteryPropertyName: string | symbol,
methodNames?: readonly string[],
): <T extends new (...arguments_: readonly any[]) => any>(klass: T) => T
In TypeScript, it returns a decorator which mixins Emittery as property emitteryPropertyName and methodNames, or all Emittery methods if methodNames is not defined, into the target class.
Parameters
- emitteryPropertyName: string | symbol
- OptionalmethodNames: readonly string[]
Returns <T extends new (...arguments_: readonly any[]) => any>(klass: T) => T
Example
```
import Emittery from 'emittery';

@Emittery.mixin('emittery')
class MyClass {}

const instance = new MyClass();

instance.emit('event');
```
Inherited from Emittery.mixin

Class SerialPortClient

Example

Hierarchy

Index

Constructors

Properties

Accessors

Methods

Constructors

constructor

Parameters

Returns SerialPortClient

Example

Properties

debug

StaticisDebugEnabled

Example

Static ReadonlylistenerAdded

Example

Static ReadonlylistenerRemoved

Example

Accessors

id

Returns string

Example

isOpen

Returns boolean

Example

Methods

anyEvent

Returns AsyncIterableIterator< [ "data" | "error" | "close", undefined | Buffer<ArrayBufferLike> | Error, ],>

Example

bindMethods

Parameters

Returns void

Example

clearListeners

Type Parameters

Parameters

Returns void

close

Returns Promise<void>

Throws

Example

emit

Type Parameters

Parameters

Returns Promise<void>

Type Parameters

Parameters

Returns Promise<void>

emitSerial

Type Parameters

Parameters

Returns Promise<void>

Type Parameters

Parameters

Returns Promise<void>

events

Type Parameters

Parameters

Returns AsyncIterableIterator<{ close: undefined; data: Buffer; error: Error }[Name]>

Example

Example

Example

listenerCount

Type Parameters

Parameters

Returns number

off

Type Parameters

Parameters

Returns void

Example

offAny

Parameters

Returns void

on

Type Parameters

Parameters

`Static`isDebugEnabled

`Static` `Readonly`listenerAdded

`Static` `Readonly`listenerRemoved

Returns AsyncIterableIterator<
[
"data"
| "error"
| "close",
undefined | Buffer<ArrayBufferLike> | Error,
],
>

Returns EmitteryOncePromise<
(
{ close: undefined; data: Buffer; error: Error } & OmnipresentEventData
)[Name],
>

`Static`list

`Static`mixin