Mobile LA518 Recorder

A NativePHP Mobile plugin that talks to LA518-based BLE voice recorders (Umevo Note Plus and OEM rebadges using the same chip). Connect, list recordings, start/stop recording from your app, download MP3s, and consume live audio + VU level data — all from PHP and JavaScript.

The full BLE protocol was reverse-engineered from PacketLogger captures of the official iOS app. See PROTOCOL.md for the complete wire-level spec — frame format, opcode table, handshake sequence, file listing, recording control, downloads, live VU/audio streams, and end-of-transfer flag semantics.

Installation

composer require wojt-janowski/mobile-la518-recorder
php artisan vendor:publish --tag=nativephp-plugins-provider     # first time only
php artisan native:plugin:register wojt-janowski/mobile-la518-recorder
php artisan native:plugin:list                                    # verify

Permissions

Android (auto-merged into your AndroidManifest.xml)

• BLUETOOTH, BLUETOOTH_ADMIN
• BLUETOOTH_SCAN, BLUETOOTH_CONNECT (Android 12+)
• ACCESS_FINE_LOCATION (required for BLE scanning)

iOS (auto-merged into your Info.plist)

• NSBluetoothAlwaysUsageDescription
• NSBluetoothPeripheralUsageDescription

You'll be prompted by the OS the first time connect() is called.

PHP usage (Livewire/Blade)

use WojtJanowski\MobileLa518Recorder\Facades\MobileLa518Recorder;

// Discover and bind. Returns 15-char device serial, or null on failure.
$serial = MobileLa518Recorder::connect();

// List stored recordings — array of ['name' => '...', 'size' => bytes, 'duration' => seconds]
$files = MobileLa518Recorder::listFiles();

// Start a new recording on the device
$filename = MobileLa518Recorder::startRecording();

// …user does something for a while…

// Stop. Returns ['filename' => '...', 'size' => bytes, 'mode' => 'normal'|'call']
$ack = MobileLa518Recorder::stopRecording();

// Download a stored recording. Returns absolute local file path.
$localPath = MobileLa518Recorder::downloadFile($filename);

Listening to events

use Native\Mobile\Attributes\OnNative;
use WojtJanowski\MobileLa518Recorder\Events\{
    DeviceConnected, DeviceDisconnected,
    RecordingStarted, RecordingStopped,
    VuLevel, LiveAudioChunk,
    DownloadProgress, DownloadCompleted,
};

class Recorder extends Livewire\Component
{
    public int $vuLevel = 0;

    #[OnNative(VuLevel::class)]
    public function onVu($level, $deltaSinceLast)
    {
        $this->vuLevel = $level;
    }

    #[OnNative(LiveAudioChunk::class)]
    public function onChunk($filename, $base64Data, $sequenceIndex)
    {
        // base64-decode into a buffer, stream to a transcriber, etc.
    }

    #[OnNative(RecordingStopped::class)]
    public function onStopped($filename, $size, $mode)
    {
        // Recording is now persisted on the device — fetch it
        $localPath = MobileLa518Recorder::downloadFile($filename);
    }
}

JavaScript usage (Vue/React/Inertia)

import { MobileLa518Recorder, Events } from '@wojt-janowski/mobile-la518-recorder';
import { on, off } from '@nativephp/native';

const serial = await MobileLa518Recorder.connect();
const files  = await MobileLa518Recorder.listFiles();

const handler = ({ level }) => updateMeter(level);
on(Events.VuLevel, handler);

await MobileLa518Recorder.startRecording();
// …
const result = await MobileLa518Recorder.stopRecording();

off(Events.VuLevel, handler);

Available methods

Method	Returns	Notes
connect(int $scanTimeoutSeconds = 10)	string|null	Device serial. Requests fast BLE mode.
disconnect()	bool	Closes BLE link; does not stop a running recording.
isConnected()	bool
listFiles()	array	Each row: ['name', 'size', 'duration'].
startRecording()	string|null	Recording filename (YYYYMMDDHHMMSS).
stopRecording()	array|null	['filename', 'size', 'mode'], mode = normal or call.
downloadFile(string $name)	string|null	Absolute local file path.

Event payloads

Event	Properties
DeviceConnected	serial: string
DeviceDisconnected	reason: ?string
RecordingStarted	filename: string
RecordingStopped	filename: string, size: int, mode: string
VuLevel	level: int (0..65535), deltaSinceLast: int
LiveAudioChunk	filename: string, base64Data: string (raw F0F3 chunk), sequenceIndex: int
DownloadProgress	filename: string, bytesReceived: int, totalBytes: int
DownloadCompleted	filename: string, localPath: string, size: int

Protocol reference

The complete reverse-engineered BLE protocol — GATT layout, frame format, every opcode, the bind handshake, file-listing format, recording control, download flow, live VU/audio streams, and call-mode flag semantics — is documented in PROTOCOL.md.

Quick summary:

• Audio output: MP3, 32 kbps, 16 kHz, mono
• Custom GATT service F0F0 with TX (F0F1), control RX (F0F2), live stream (F0F3), and download stream (F0F4) characteristics
• Frame envelope: 80 08 02 [op] [len] [body] [trailer]
• Mandatory bind handshake within ~3 s of connecting (challenge "131186")