getAllDevices

Introduction

getAllDevices is a synchronous query function that returns all visible Bluetooth devices. This includes devices that are already paired, devices that are currently connected, and nearby BLE devices that are actively broadcasting. It performs a single snapshot scan — the result reflects the device state at the exact moment of invocation.

Signature

function getAllDevices(): BluetoothDeviceInfo[]

• Returns: An array of BluetoothDeviceInfo objects.
• Throws: This function does not throw under normal operation.

Usage

getAllDevices is the broadest query available in @eisland/windows-bluetooth-helper. It is ideal when you need a complete picture of the Bluetooth landscape around the user — for example, populating a device picker UI, performing a one-time environment scan, or building a quick diagnostics view.

For narrower queries, consider:

• getPairedDevices — only paired devices
• getConnectedDevices — only connected devices
• getDevice — single device by ID

When to prefer getAllDevices vs. a Monitor

getAllDevices gives you a one-time snapshot. If you need to react to devices appearing, disappearing, or changing connection state in real time, use BluetoothMonitor instead. Calling getAllDevices in a polling loop is less efficient than subscribing to monitor events.

Device discovery scope

The result includes paired devices (from the Windows Bluetooth settings cache), connected devices (actively linked), and nearby BLE devices (those currently advertising). Classic Bluetooth devices that are powered on but not paired and not discoverable will NOT appear.

Return Value

An array of BluetoothDeviceInfo objects. Each object contains the following fields:

Property	Type	Description
deviceId	string	Windows DeviceInformation ID
name	string | null	Friendly device name, or null if unavailable
bluetoothAddress	string | null	MAC address as a hex string, or null
isConnected	boolean	Whether the device is currently connected
isPaired	boolean	Whether the device is paired with the system
signalStrength	number | null	RSSI in dBm, or null if unavailable
deviceClass	number | null	Class of Device (CoD) bitmask value
appearance	number | null	BLE Appearance category value
serviceUuids	string[]	GATT service UUIDs the device advertises
deviceType	string | null	Human-readable type derived from CoD or Appearance
batteryLevel	number | null	Battery percentage (0-100), BLE devices only

Null fields are common

Not every device exposes all fields. Classic Bluetooth devices typically have appearance as null, while BLE devices may have deviceClass as null. batteryLevel is only available on BLE devices that expose the Battery Service (UUID 0x180F). Always null-check before using optional fields.

Example

TypeScript

import { getAllDevices } from '@eisland/windows-bluetooth-helper';

// Query all visible Bluetooth devices (paired + nearby BLE)
const devices = getAllDevices();

// Iterate and log each device with its connection status
devices.forEach((d) => {
  // Determine human-readable status: connected, paired, or just discoverable
  const status = d.isConnected ? 'Connected' : d.isPaired ? 'Paired' : 'Discoverable';
  // Print device name (fall back to "Unknown" if name is null)
  console.log(`[${status}] ${d.name ?? 'Unknown'}`);
});

// Filter for only connected devices
const connected = devices.filter((d) => d.isConnected);
console.log(`Connected devices: ${connected.length}`);

// Filter for BLE devices that report battery level
const withBattery = devices.filter((d) => d.batteryLevel !== null);
withBattery.forEach((d) => {
  console.log(`${d.name}: ${d.batteryLevel}% battery`);
});

JavaScript

const { getAllDevices } = require('@eisland/windows-bluetooth-helper');

// Query all visible Bluetooth devices (paired + nearby BLE)
const devices = getAllDevices();

// Iterate and log each device with its connection status
devices.forEach((d) => {
  // Determine human-readable status: connected, paired, or just discoverable
  const status = d.isConnected ? 'Connected' : d.isPaired ? 'Paired' : 'Discoverable';
  // Print device name (fall back to "Unknown" if name is null)
  console.log(`[${status}] ${d.name ?? 'Unknown'}`);
});

// Filter for only connected devices
const connected = devices.filter((d) => d.isConnected);
console.log(`Connected devices: ${connected.length}`);

// Filter for BLE devices that report battery level
const withBattery = devices.filter((d) => d.batteryLevel !== null);
withBattery.forEach((d) => {
  console.log(`${d.name}: ${d.batteryLevel}% battery`);
});

Notes

Snapshot behavior

getAllDevices returns a point-in-time snapshot. The array you receive is a plain JavaScript array — it will not auto-update. If a device connects or disconnects after the call, your data will be stale. For live updates, use BluetoothMonitor.

Combining with other queries

You can pass a deviceId from getAllDevices results directly to getDevice to refresh a single device's state without re-scanning everything.

BLE discovery timing

Nearby BLE devices appear only while they are actively advertising. If a BLE device stops broadcasting (e.g., enters sleep), it may disappear from subsequent getAllDevices calls even though it is still physically nearby.

Danger Avoidance

Do not poll aggressively

Calling getAllDevices in a tight loop (e.g., setInterval(fn, 100)) will repeatedly invoke the native Bluetooth stack, consuming CPU and potentially interfering with active Bluetooth connections. Use BluetoothMonitor for real-time updates instead. If you must poll, keep the interval at 5 seconds or longer.

Bluetooth adapter must be enabled

If the system's Bluetooth adapter is disabled or absent, getAllDevices returns an empty array. It does not throw an error. If you receive an unexpectedly empty result, verify that Bluetooth is enabled in Windows Settings before assuming there are no nearby devices.