Initial commit: FieldLogger MAUI app with Maglink BLE support

Added Maglink RTK GNSS receiver integration with correct BLE UUIDs and device name filtering (ML-* prefix). 🤖 Generated with [Claude Code](https://claude.com/claude-code) Co-Authored-By: Claude <noreply@anthropic.com>
2026-07-06 13:46:50 -05:00
commit b602b762c9
79 changed files with 5807 additions and 0 deletions
--- a/FieldLogger/Services/MaglinkService.cs
+++ b/FieldLogger/Services/MaglinkService.cs
@@ -0,0 +1,98 @@
+using FieldLogger.Models;
+using FieldLogger.Services.Ble;
+using Microsoft.Extensions.Logging;
+
+namespace FieldLogger.Services;
+
+/// <summary>
+/// Manages the connection to the Maglink (H11) RTK GNSS receiver: parses the
+/// $GNPOS / $GNDEV custom NMEA stream and sends AT configuration commands.
+/// </summary>
+public sealed class MaglinkService : IAsyncDisposable
+{
+    public static readonly Guid ServiceUuid = Guid.Parse("0000fff0-0000-1000-8000-00805f9b34fb");
+    public static readonly Guid NotifyUuid = Guid.Parse("0000fff2-0000-1000-8000-00805f9b34fb");
+    public static readonly Guid WriteUuid = Guid.Parse("0000fff2-0000-1000-8000-00805f9b34fb");
+
+    private readonly BleSerialClient _client = new();
+    private readonly ILogger<MaglinkService> _logger;
+
+    public GnssFix? LatestFix { get; private set; }
+    public GnssDeviceInfo? DeviceInfo { get; private set; }
+    public bool IsConnected => _client.IsConnected;
+    public string? DeviceName => _client.DeviceName;
+
+    public event EventHandler<GnssFix>? FixReceived;
+    public event EventHandler<GnssDeviceInfo>? DeviceInfoReceived;
+    public event EventHandler? Disconnected;
+
+    /// <summary>Device-name filter for scan results (ML-*).</summary>
+    public static bool IsMaglinkName(string? name) =>
+        name is not null && name.StartsWith("ML-", StringComparison.OrdinalIgnoreCase);
+
+    public MaglinkService(ILogger<MaglinkService> logger)
+    {
+        _logger = logger;
+        _client.LineReceived += OnLineReceived;
+        _client.Disconnected += (_, _) => Disconnected?.Invoke(this, EventArgs.Empty);
+    }
+
+    public async Task ConnectAsync(Guid deviceId, CancellationToken cancellationToken = default)
+    {
+        await _client.ConnectAsync(deviceId, ServiceUuid, NotifyUuid, WriteUuid, cancellationToken);
+
+        // Custom mode with GNPOS + GNDEV only - everything the app needs, minimal traffic.
+        await SendCommandAsync("AT+BT_OUT=SET,1,0,1,1,0,0,0,0,0,0", cancellationToken);
+    }
+
+    /// <summary>Sends an AT command (terminator appended automatically).</summary>
+    public Task SendCommandAsync(string command, CancellationToken cancellationToken = default)
+        => _client.WriteLineAsync(command, cancellationToken);
+
+    public Task DisconnectAsync() => _client.DisconnectAsync();
+
+    /// <summary>A fix received within the last few seconds, or null if the stream has gone stale.</summary>
+    public GnssFix? FreshFix(TimeSpan? maxAge = null)
+    {
+        var fix = LatestFix;
+        if (fix is null)
+            return null;
+        return DateTime.UtcNow - fix.ReceivedUtc <= (maxAge ?? TimeSpan.FromSeconds(5)) ? fix : null;
+    }
+
+    private void OnLineReceived(object? sender, string line)
+    {
+        if (line.StartsWith("$GNPOS,", StringComparison.Ordinal))
+        {
+            if (!NmeaSentence.VerifyChecksum(line))
+            {
+                _logger.LogWarning("GNPOS checksum failed: {Line}", line);
+                return;
+            }
+            var fix = GnssFix.TryParse(line);
+            if (fix is not null)
+            {
+                LatestFix = fix;
+                FixReceived?.Invoke(this, fix);
+            }
+        }
+        else if (line.StartsWith("$GNDEV,", StringComparison.Ordinal))
+        {
+            if (!NmeaSentence.VerifyChecksum(line))
+                return;
+            var info = GnssDeviceInfo.TryParse(line);
+            if (info is not null)
+            {
+                DeviceInfo = info;
+                DeviceInfoReceived?.Invoke(this, info);
+            }
+        }
+        else
+        {
+            // AT command responses and anything else.
+            _logger.LogDebug("Maglink rx: {Line}", line);
+        }
+    }
+
+    public ValueTask DisposeAsync() => _client.DisposeAsync();
+}