fgh

IOModuleTestBlazor/CanWorker.cs

@@ -15,27 +15,26 @@ public class CanWorker(
 {
     public override Task StartAsync(CancellationToken cancellationToken)
     {
-        var channel = ResolveChannel();
+        // Seed filters and bitmasks from appsettings regardless of connection state
-        var bitrate = ResolveBitrate();
-
-        try
-        {
-            canService.Initialize(channel, bitrate);
-        }
-        catch (InvalidOperationException ex)
-        {
-            logger.LogError(ex, "Failed to initialize CAN channel {Channel}", channel);
-            throw;
-        }
-
-        // Seed filters and bitmasks from appsettings
         foreach (var f in configuration.GetSection("CanOptions:Filters").Get<CanFilter[]>() ?? [])
             canService.AddFilter(f);
-
         foreach (var b in configuration.GetSection("CanOptions:Bitmasks").Get<CanBitmask[]>() ?? [])
             canService.AddBitmask(b);
 
+        // Auto-connect if config is present; failures are non-fatal so the app
+        // still starts and the user can configure the connection from the UI.
+        try
+        {
+            var channel = ResolveChannel();
+            var bitrate = ResolveBitrate();
+            canService.Initialize(channel, bitrate);
             logger.LogInformation("CAN channel {Channel} ready at {Bitrate}", channel, bitrate);
+        }
+        catch (Exception ex)
+        {
+            logger.LogWarning(ex, "CAN auto-connect failed — configure via the UI.");
+        }
+
         return base.StartAsync(cancellationToken);
     }
 
@@ -43,6 +42,29 @@ public class CanWorker(
     {
         while (!stoppingToken.IsCancellationRequested)
         {
+            // Pick up any reinit request from the UI
+            if (canService.TryConsumePendingReinit(out var newChannel, out var newBitrate))
+            {
+                logger.LogInformation("Reinitializing CAN: {Channel} at {Bitrate}", newChannel, newBitrate);
+                if (canService.IsConnected) canService.Uninitialize();
+                try
+                {
+                    canService.Initialize(newChannel, newBitrate);
+                    logger.LogInformation("CAN reinitialized: {Channel} at {Bitrate}", newChannel, newBitrate);
+                }
+                catch (Exception ex)
+                {
+                    logger.LogError(ex, "CAN reinitialization failed.");
+                }
+                continue;
+            }
+
+            if (!canService.IsConnected)
+            {
+                await Task.Delay(100, stoppingToken);
+                continue;
+            }
+
             var result = canService.Read(out PcanMessage msg, out ulong timestamp);
 
             if (result == PcanStatus.OK)
@@ -97,11 +119,10 @@ public class CanWorker(
             return configured;
 
         logger.LogInformation("No channel configured — scanning for available PCAN USB channels...");
-        var available = GetAvailableUsbChannels();
+        var available = canService.GetAvailableChannels();
 
         if (available.Count == 0)
-            throw new InvalidOperationException(
+            throw new InvalidOperationException("No PCAN USB channels detected.");
-                "No PCAN USB channels detected. Set CanOptions:Channel in appsettings.json.");
 
         logger.LogInformation("Auto-selected channel: {Channel}", available[0]);
         return available[0];
@@ -118,20 +139,6 @@ public class CanWorker(
         return Bitrate.Pcan500;
     }
 
-    private static List<PcanChannel> GetAvailableUsbChannels()
-    {
-        var available = new List<PcanChannel>();
-        foreach (var ch in Enum.GetValues<PcanChannel>()
-            .Where(c => c.ToString().StartsWith("Usb", StringComparison.OrdinalIgnoreCase))
-            .OrderBy(c => c.ToString()))
-        {
-            var result = Api.GetValue(ch, PcanParameter.ChannelCondition, out uint condition);
-            if (result == PcanStatus.OK && condition != 0)
-                available.Add(ch);
-        }
-        return available;
-    }
-
     private static string GetErrorText(PcanStatus status)
     {
         try { Api.GetErrorText(status, out var text); return text; }

IOModuleTestBlazor/Components/Pages/CanMonitor.razor

@@ -10,18 +10,73 @@
 
 <h1>CAN Monitor</h1>
 
-@* ── Status bar ─────────────────────────────────────────────────────────────── *@
+@* ── Connection ──────────────────────────────────────────────────────────────── *@
-<div class="d-flex align-items-center gap-3 mb-3">
+<div class="card mb-3">
-    @if (CanService.IsConnected)
+    <div class="card-body py-2">
+        @if (CanService.IsConnected && !showConnectionForm)
         {
-        <span class="badge bg-success fs-6">● Connected</span>
+            <div class="d-flex align-items-center gap-3">
-        <span class="text-muted">Channel: <strong>@CanService.ChannelName</strong></span>
+                <span class="badge bg-success">● Connected</span>
+                <span class="font-monospace fw-semibold">@CanService.ChannelName</span>
+                <span class="text-muted">@BitrateLabel(CanService.CurrentBitrate)</span>
+                <button class="btn btn-sm btn-outline-secondary ms-auto"
+                        @onclick="() => { showConnectionForm = true; ScanChannels(); }">
+                    Change
+                </button>
+            </div>
         }
         else
         {
-        <span class="badge bg-danger fs-6">○ Not connected</span>
+            <div class="row g-2 align-items-end">
-        <span class="text-muted small">Check that a PCAN USB adapter is plugged in and CanOptions are set in appsettings.json.</span>
+                <div class="col-auto">
+                    <label class="form-label small mb-0">Channel</label>
+                    <select class="form-select form-select-sm font-monospace" @bind="selectedChannel"
+                            style="min-width:100px">
+                        @if (availableChannels.Count == 0)
+                        {
+                            <option value="">— none found —</option>
                         }
+                        @foreach (var ch in availableChannels)
+                        {
+                            <option value="@ch.ToString()">@ch.ToString()</option>
+                        }
+                    </select>
+                </div>
+                <div class="col-auto">
+                    <label class="form-label small mb-0">Bitrate</label>
+                    <select class="form-select form-select-sm" @bind="selectedBitrate"
+                            style="min-width:120px">
+                        @foreach (var (val, label) in BitrateOptions)
+                        {
+                            <option value="@val.ToString()">@label</option>
+                        }
+                    </select>
+                </div>
+                <div class="col-auto d-flex gap-2">
+                    <button class="btn btn-sm btn-outline-secondary" @onclick="ScanChannels">Scan</button>
+                    <button class="btn btn-sm btn-primary" @onclick="Connect"
+                            disabled="@(availableChannels.Count == 0 || isConnecting)">
+                        @(isConnecting ? "Connecting…" : CanService.IsConnected ? "Reconnect" : "Connect")
+                    </button>
+                    @if (CanService.IsConnected)
+                    {
+                        <button class="btn btn-sm btn-outline-secondary"
+                                @onclick="() => showConnectionForm = false">Cancel</button>
+                    }
+                </div>
+            </div>
+            @if (availableChannels.Count == 0)
+            {
+                <div class="text-warning small mt-1">
+                    No PCAN USB channels detected. Plug in your adapter and click Scan.
+                </div>
+            }
+            @if (connectError != null)
+            {
+                <div class="text-danger small mt-1">@connectError</div>
+            }
+        }
+    </div>
 </div>
 
 @* ── Live messages ──────────────────────────────────────────────────────────── *@
@@ -294,6 +349,28 @@
 </div>
 
 @code {
+    // ── Connection form ───────────────────────────────────────────────────────
+    private List<PcanChannel> availableChannels = [];
+    private string selectedChannel = "";
+    private string selectedBitrate = Bitrate.Pcan500.ToString();
+    private bool showConnectionForm;
+    private bool isConnecting;
+    private string? connectError;
+
+    private static readonly (Bitrate Value, string Label)[] BitrateOptions =
+    [
+        (Bitrate.Pcan1000, "1000 kbps"),
+        (Bitrate.Pcan800,  "800 kbps"),
+        (Bitrate.Pcan500,  "500 kbps"),
+        (Bitrate.Pcan250,  "250 kbps"),
+        (Bitrate.Pcan125,  "125 kbps"),
+        (Bitrate.Pcan100,  "100 kbps"),
+        (Bitrate.Pcan50,   "50 kbps"),
+        (Bitrate.Pcan20,   "20 kbps"),
+        (Bitrate.Pcan10,   "10 kbps"),
+        (Bitrate.Pcan5,    "5 kbps"),
+    ];
+
     // ── Data ──────────────────────────────────────────────────────────────────
     private readonly List<CanMessageDto> messages = [];
     private readonly Dictionary<uint, CanMessageDto> latestMessages = new();
@@ -333,6 +410,17 @@
         filters = CanService.Filters.ToList();
         bitmasks = CanService.Bitmasks.ToList();
         CanService.MessageReceived += OnMessageReceived;
+
+        ScanChannels();
+        if (CanService.IsConnected)
+        {
+            selectedChannel = CanService.ChannelName;
+            selectedBitrate = CanService.CurrentBitrate.ToString();
+        }
+        else
+        {
+            showConnectionForm = true;
+        }
     }
 
     private void OnMessageReceived(CanMessageDto msg)
@@ -344,15 +432,71 @@
                 messages.RemoveAt(messages.Count - 1);
         }
         lock (latestMessages)
+        {
+            if (!latestMessages.TryGetValue(msg.Id, out var existing) ||
+                !msg.Data.SequenceEqual(existing.Data))
             {
                 latestMessages[msg.Id] = msg;
                 updateCounts[msg.Id] = updateCounts.GetValueOrDefault(msg.Id) + 1;
             }
+        }
         InvokeAsync(StateHasChanged);
     }
 
     public void Dispose() => CanService.MessageReceived -= OnMessageReceived;
 
+    // ── Connection ────────────────────────────────────────────────────────────
+
+    private void ScanChannels()
+    {
+        availableChannels = CanService.GetAvailableChannels().ToList();
+        if (availableChannels.Count > 0 &&
+            !availableChannels.Any(c => c.ToString() == selectedChannel))
+            selectedChannel = availableChannels[0].ToString();
+    }
+
+    private async Task Connect()
+    {
+        connectError = null;
+        if (!Enum.TryParse<PcanChannel>(selectedChannel, out var channel))
+        { connectError = "Please select a channel."; return; }
+        if (!Enum.TryParse<Bitrate>(selectedBitrate, out var bitrate))
+        { connectError = "Please select a bitrate."; return; }
+
+        isConnecting = true;
+        CanService.RequestReinitialize(channel, bitrate);
+
+        // Poll until the worker completes the reinit (typically < 50 ms)
+        for (int i = 0; i < 20; i++)
+        {
+            await Task.Delay(100);
+            if (CanService.IsConnected) break;
+        }
+
+        isConnecting = false;
+        if (CanService.IsConnected)
+            showConnectionForm = false;
+        else
+            connectError = "Connection failed. Check the adapter is plugged in and try again.";
+
+        StateHasChanged();
+    }
+
+    private static string BitrateLabel(Bitrate b) => b switch
+    {
+        Bitrate.Pcan1000 => "1000 kbps",
+        Bitrate.Pcan800  => "800 kbps",
+        Bitrate.Pcan500  => "500 kbps",
+        Bitrate.Pcan250  => "250 kbps",
+        Bitrate.Pcan125  => "125 kbps",
+        Bitrate.Pcan100  => "100 kbps",
+        Bitrate.Pcan50   => "50 kbps",
+        Bitrate.Pcan20   => "20 kbps",
+        Bitrate.Pcan10   => "10 kbps",
+        Bitrate.Pcan5    => "5 kbps",
+        _                => b.ToString()
+    };
+
     // ── Messages ──────────────────────────────────────────────────────────────
 
     private void ClearMessages()

IOModuleTestBlazor/Services/CanService.cs

@@ -11,7 +11,10 @@ public class CanService : ICanService
     private readonly object _lock = new();
 
     public bool IsConnected { get; private set; }
-    public string ChannelName => _channel.ToString();
+    public string ChannelName => IsConnected ? _channel.ToString() : "";
+    public Bitrate CurrentBitrate { get; private set; }
+
+    private (PcanChannel Channel, Bitrate Bitrate)? _pendingReinit;
 
     public event Action<CanMessageDto>? MessageReceived;
 
@@ -103,6 +106,42 @@ public class CanService : ICanService
 
     // ── PCAN passthrough ──────────────────────────────────────────────────────
 
+    public IReadOnlyList<PcanChannel> GetAvailableChannels()
+    {
+        var available = new List<PcanChannel>();
+        foreach (var ch in Enum.GetValues<PcanChannel>()
+            .Where(c => c.ToString().StartsWith("Usb", StringComparison.OrdinalIgnoreCase))
+            .OrderBy(c => c.ToString()))
+        {
+            var result = Api.GetValue(ch, PcanParameter.ChannelCondition, out uint condition);
+            if (result == PcanStatus.OK && condition != 0)
+                available.Add(ch);
+        }
+        return available;
+    }
+
+    public void RequestReinitialize(PcanChannel channel, Bitrate bitrate)
+    {
+        lock (_lock) _pendingReinit = (channel, bitrate);
+    }
+
+    public bool TryConsumePendingReinit(out PcanChannel channel, out Bitrate bitrate)
+    {
+        lock (_lock)
+        {
+            if (_pendingReinit.HasValue)
+            {
+                channel = _pendingReinit.Value.Channel;
+                bitrate = _pendingReinit.Value.Bitrate;
+                _pendingReinit = null;
+                return true;
+            }
+            channel = default;
+            bitrate = default;
+            return false;
+        }
+    }
+
     public void Initialize(PcanChannel channel, Bitrate bitrate)
     {
         _channel = channel;
@@ -110,6 +149,7 @@ public class CanService : ICanService
         if (result != PcanStatus.OK)
             throw new InvalidOperationException($"CAN init failed: {GetErrorText(result)}");
         IsConnected = true;
+        CurrentBitrate = bitrate;
     }
 
     public void Uninitialize()

IOModuleTestBlazor/Services/ICanService.cs

@@ -7,6 +7,7 @@ public interface ICanService
 {
     bool IsConnected { get; }
     string ChannelName { get; }
+    Bitrate CurrentBitrate { get; }
 
     /// <summary>
     /// Raised on the worker thread each time a CAN message passes all filters.
@@ -31,6 +32,20 @@ public interface ICanService
     IReadOnlyDictionary<string, double> ExtractSignals(uint messageId, byte[] data);
     void PublishMessage(CanMessageDto dto);
 
+    // ── Channel management ────────────────────────────────────────────────────
+
+    /// <summary>Returns all PCAN USB channels that are currently available.</summary>
+    IReadOnlyList<PcanChannel> GetAvailableChannels();
+
+    /// <summary>
+    /// Asks the worker to reinitialise on the next loop iteration.
+    /// Non-blocking — the actual reconnect happens asynchronously.
+    /// </summary>
+    void RequestReinitialize(PcanChannel channel, Bitrate bitrate);
+
+    /// <summary>Called by the worker to pick up a pending reinit request.</summary>
+    bool TryConsumePendingReinit(out PcanChannel channel, out Bitrate bitrate);
+
     // ── PCAN passthrough ──────────────────────────────────────────────────────
     void Initialize(PcanChannel channel, Bitrate bitrate);
     void Uninitialize();