blueswarm

Find and connect to nearby peers over Bluetooth LE.

Usage

import BlueSwarm from "blueswarm"

const swarm = new BlueSwarm(serviceUUID, characteristicUUID)

swarm.on("connection", (socket) => {
  // socket is a Duplex stream, pipe it somewhere
  socket.on("error", console.error)
})

await swarm.ready()

const client = Math.random() < 0.5
swarm.join({ advertise: !client, scan: client })

// When you're done
await swarm.close()

API

const swarm = new BlueSwarm(serviceUUID: string, characteristicUUID: string)

Construct a new BlueSwarm instance. serviceUUID and characteristicUUID must be valid UUIDs formatted to string.

swarm.serviceUUID: string

The service UUID used to discover peers and exchange data.

swarm.characteristicUUID: string

The characteristic UUID used to exchange data.

swarm.connections: Set<Socket>

A set of currently active connections.

swarm.advertising: boolean

Whether the swarm is currently advertising.

swarm.scanning: boolean

Whether the swarm is actively scanning for new devices.

await swarm.ready()

Initialize the swarm. Must be called once on startup. The swarm won't initiate or accept connections until this resolves.

await swarm.close()

Close all active connections and free up resources. The swarm cannot be used after calling this.

swarm.join({ advertise = true, scan = true })

Do not join in both advertising and scanning modes at the same time. This wastes battery and may cause connection issues, especially if your peers are on both iOS and Android

Join the swarm! Starts advertising this device as connectable and/or scanning for compatible devices to connect to.

swarm.leave()

Stop scanning and advertising. This does not affect existing connections. It's a good idea to call this once you have a few connections to save battery life.

swarm.on("update", () => {})

Emitted when internal state changes, e.g. connection/disconnect.

swarm.on("connection", (socket) => {})

Emitted whenever swarm connects to a new device.

socket.client: boolean

Whether this connection is in client mode.

socket.server: boolean

Whether this connection is in server mode.