switch-joy-con

Use Nintendo Switch Joy-Cons as input devices (Bluetooth).

Features

- Run callback(s) when buttons are pressed/released/changed
- Toggle player LEDs

Installation

``
npm install --save switch-joy-con
`

Usage

`js
const { listConnectedJoyCons } = require("switch-joy-con");

// First, list all the Joy-Cons connected to the computer.
const devices = listConnectedJoyCons();
console.log(devices);
// [
// {
// vendorId: 1406,
// productId: 8198,
// path: 'IOService:/IOResources/IOBluetoothHCIController/AppleBroadcomBluetoothHostController/IOBluetoothDevice/IOBluetoothL2CAPChannel/IOBluetoothHIDDriver',
// serialNumber: '94-58-cb-a6-1b-86',
// manufacturer: 'Unknown',
// product: 'Joy-Con (L)',
// release: 1,
// interface: -1,
// usagePage: 1,
// usage: 5,
// open: [Function: open]
// },
// {
// vendorId: 1406,
// productId: 8199,
// path: 'IOService:/IOResources/IOBluetoothHCIController/AppleBroadcomBluetoothHostController/IOBluetoothDevice/IOBluetoothL2CAPChannel/IOBluetoothHIDDriver',
// serialNumber: '94-58-cb-a5-cb-9d',
// manufacturer: 'Unknown',
// product: 'Joy-Con (R)',
// release: 1,
// interface: -1,
// usagePage: 1,
// usage: 5,
// open: [Function: open]
// }
// ]

// Decide which to use, and then call open on it.
const left = devices[0].open();

// The buttons property always contains up-to-date buttons state:
console.log(left.buttons);
// {
// dpadUp: false,
// dpadDown: false,
// dpadLeft: false,
// dpadRight: false,
// minus: false,
// screenshot: false,
// sl: false,
// sr: false,
// l: false,
// zl: false,
// analogStickPress: false,
// analogStick: left.Directions.NEUTRAL
// }

// A "change" event will be emitted whenever the button state changes
left.on("change", () => {
console.log(left.buttons);
});

// Whenever a button is pressed or released, a down:${buttonName} or up:${buttonName} event is emitted.
left.on("down:minus", () => {
console.log("minus pressed down");
});
left.on("up:minus", () => {
console.log("minus depressed");
});

// a change:${buttonName} event is also emitted:
left.on("change:minus", pressed => {
console.log(minus is now: ${pressed ? "pressed" : "unpressed"});
});

// The analogStick "button" is a number. Use the Directions property on the
// instance to understand its value:
left.on("change:analogStick", value => {
switch (value) {
case left.Directions.UP: {
console.log("up");
break;
}
case left.Directions.UP_RIGHT: {
console.log("up-right");
break;
}
case left.Directions.RIGHT: {
console.log("right");
break;
}
case left.Directions.DOWN_RIGHT: {
console.log("down-right");
break;
}
case left.Directions.DOWN: {
console.log("down");
break;
}
case left.Directions.DOWN_LEFT: {
console.log("down-left");
break;
}
case left.Directions.LEFT: {
console.log("left");
break;
}
case left.Directions.UP_LEFT: {
console.log("up-left");
break;
}
case left.Directions.UP_RIGHT: {
console.log("up-right");
break;
}
case left.Directions.NEUTRAL: {
console.log("neutral");
break;
}
}
});

// When you're done with the device, call close on it:
left.close();

// Usage with a right-side Joy-Con is the same, but it has different button names:
const right = devices[1].open();
console.log(right.buttons);
// {
// a: false,
// x: false,
// b: false,
// y: false,
// plus: false,
// home: false,
// sl: false,
// sr: false,
// r: false,
// zr: false,
// analogStickPress: false,
// analogStick: right.Directions.NEUTRAL
// }

// If you need to tell whether a Joy-Con is a left or right Joy-Con, use the side property:
console.log(left.side); // "left"
console.log(right.side); // "right"
`

API Documentation

The "switch-joy-con" module has one named export, listConnectedJoyCons.

$3

Returns an array of objects, each describing a connected Joy-Con.

The objects have the following properties:

`ts
interface JoyConDescription {
vendorId: number;
productId: number;
path: string;
serialNumber: string;
manufacturer: string;
product: string;
release: number;
interface: number;
usagePage: number;
usage: number;
open: () => JoyCon;
}
`

The most important thing here is the open method, which returns a JoyCon instance.

$3

You can obtain a JoyCon instance by calling open on a JoyConDescription, as returned by listConnectedJoyCons().

Each JoyCon adheres to the following interface:

`ts
interface JoyCon extends EventEmitter {
// Whether the Joy-Con attaches to the left or right side of a Switch.
// The buttons will differ depending on this.
side: "left" | "right";

// An object containing the current button state.
buttons: // If side is "left", buttons will have the following properties:
| {
// If a button is pressed, its value will be true. Otherwise, it will be false.
dpadUp: boolean;
dpadDown: boolean;
dpadLeft: boolean;
dpadRight: boolean;
minus: boolean;
screenshot: boolean;
sl: boolean;
sr: boolean;
l: boolean;
zl: boolean;
analogStickPress: boolean;

// Use the Directions property on the JoyCon to understand this number.
analogStick: number;
}
// Otherwise (if side is "right"), buttons will have these properties:
| {
// If a button is pressed, its value will be true. Otherwise, it will be false.
a: boolean;
x: boolean;
b: boolean;
y: boolean;
plus: boolean;
home: boolean;
sl: boolean;
sr: boolean;
r: boolean;
zr: boolean;
analogStickPress: boolean;

// Use the Directions property on the JoyCon to understand this number.
analogStick: number;
};

// The analog stick direction constants for this Joy-Con. Note that these differ
// between left/right Joy-Cons, so always rely on this property.
Directions: {
LEFT: number;
UP_LEFT: number;
UP: number;
UP_RIGHT: number;
RIGHT: number;
DOWN_RIGHT: number;
DOWN: number;
DOWN_LEFT: number;
NEUTRAL: number;
};

// Call this method when you are done using the Joy-Con.
// It won't be disconnected from Bluetooth, but the handle
// will be released so it can be used by another application.
close();

// LED values that can be provided to the setPlayerLEDs method.
LED_VALUES: {
// Indicates that the LED in this slot should be lit up solid.
ONE: number;
TWO: number;
THREE: number;
FOUR: number;

// Indicates that the LED in this slot should be flashing on and off.
ONE_FLASH: number;
TWO_FLASH: number;
THREE_FLASH: number;
FOUR_FLASH: number;
};

// Set which player LEDs are lit. Use value(s) from the LED_VALUES property.
// To turn on more than one LED, add them together; eg:
// setPlayerLEDs(LED_VALUES.ONE + LED_VALUES.TWO)
setPlayerLEDs(value: number);
}
`

JoyCons are also EventEmitters, and they emit the following events:

- change - Button state has changed. Inspect the buttons property on the device for more info.
- change:${buttonName} - A specific button changed state. The event listener will be called with one argument, containing the new button value.
- down:${buttonName} - A specific button is now being held down.
- up:${buttonName} - A specific button is no longer being held down.

List of button names:

- a
- x
- b
- y
- plus
- home
- l
- r
- zl
- zr
- dpadUp
- dpadDown
- dpadLeft
- dpadRight
- minus
- screenshot
- sl
- sr
- analogStickPress
- analogStick`

License

MIT