Feature/can filtering

Source/Meadow.Contracts/Hardware/Contracts/PortsAndBuses/CAN/CanAcceptanceFilter.cs

@@ -0,0 +1,28 @@
+namespace Meadow.Hardware;
+
+/// <summary>
+/// Represents a base class for CAN acceptance filters.
+/// </summary>
+public abstract class CanAcceptanceFilter
+{
+    /// <summary>
+    /// Creates a standard exact acceptance filter for the specified identifier.
+    /// </summary>
+    /// <param name="id">The identifier to be accepted by the filter.</param>
+    /// <returns>A <see cref="CanStandardExactAcceptanceFilter"/> instance.</returns>
+    public static CanAcceptanceFilter CreateStandardFilter(short id)
+    {
+        return new CanStandardExactAcceptanceFilter(id);
+    }
+
+    /// <summary>
+    /// Creates a standard range acceptance filter for the specified range of identifiers.
+    /// </summary>
+    /// <param name="firstID">The first identifier in the range to be accepted by the filter.</param>
+    /// <param name="lastID">The last identifier in the range to be accepted by the filter.</param>
+    /// <returns>A <see cref="CanStandardRangeAcceptanceFilter"/> instance.</returns>
+    public static CanAcceptanceFilter CreateStandardFilter(short firstID, short lastID)
+    {
+        return new CanStandardRangeAcceptanceFilter(firstID, lastID);
+    }
+}

Source/Meadow.Contracts/Hardware/Contracts/PortsAndBuses/CAN/CanAcceptanceFilterCollection.cs

@@ -0,0 +1,109 @@
+using System;
+using System.Collections.Generic;
+using System.ComponentModel;
+using System.Linq;
+
+namespace Meadow.Hardware;
+
+/// <summary>
+/// Represents a collection of CAN acceptance filters.
+/// </summary>
+public sealed class CanAcceptanceFilterCollection
+{
+    /// <summary>
+    /// Occurs when the collection is changed.
+    /// </summary>
+    public event EventHandler<(CollectionChangeAction Action, CanAcceptanceFilter Filter)>? CollectionChanged;
+
+    private List<CanAcceptanceFilter> _filters = new();
+
+    /// <summary>
+    /// Gets the maximum number of filters that can be contained in the collection.
+    /// </summary>
+    public int MaxFilterCount { get; }
+
+    /// <summary>
+    /// Initializes a new instance of the <see cref="CanAcceptanceFilterCollection"/> class with the specified maximum number of filters.
+    /// </summary>
+    /// <param name="maxFilterCount">The maximum number of filters that the collection can contain.</param>
+    public CanAcceptanceFilterCollection(int maxFilterCount)
+    {
+        MaxFilterCount = maxFilterCount;
+    }
+
+    /// <summary>
+    /// Gets the filter at the specified index.
+    /// </summary>
+    /// <param name="index">The zero-based index of the filter to get.</param>
+    /// <returns>The filter at the specified index.</returns>
+    public CanAcceptanceFilter this[int index]
+    {
+        get
+        {
+            lock (_filters)
+            {
+                return _filters[index];
+            }
+        }
+    }
+
+    /// <summary>
+    /// Gets the count of filters in the collection
+    /// </summary>
+    public int Count
+    {
+        get
+        {
+            lock (_filters)
+            {
+                return _filters.Count;
+            }
+        }
+    }
+
+    /// <summary>
+    /// Removes all filters from the collection.
+    /// </summary>
+    public void Clear()
+    {
+        lock (_filters)
+        {
+            foreach (var f in _filters.ToList())
+            {
+                Remove(f);
+            }
+        }
+    }
+
+    /// <summary>
+    /// Adds a filter to the collection.
+    /// </summary>
+    /// <param name="filter">The filter to add.</param>
+    public void Add(CanAcceptanceFilter filter)
+    {
+        lock (_filters)
+        {
+            if (_filters.Count >= MaxFilterCount)
+            {
+                throw new ArgumentOutOfRangeException($"Maximum filter count of {MaxFilterCount} has been reached");
+            }
+
+            _filters.Add(filter);
+        }
+
+        CollectionChanged?.Invoke(this, new(CollectionChangeAction.Add, filter));
+    }
+
+    /// <summary>
+    /// Removes a filter from the collection.
+    /// </summary>
+    /// <param name="filter">The filter to remove.</param>
+    public void Remove(CanAcceptanceFilter filter)
+    {
+        lock (_filters)
+        {
+            _filters.Remove(filter);
+        }
+        CollectionChanged?.Invoke(this, new(CollectionChangeAction.Remove, filter));
+    }
+}

Source/Meadow.Contracts/Hardware/Contracts/PortsAndBuses/CAN/CanExtendedExactAcceptanceFilter.cs

@@ -0,0 +1,21 @@
+namespace Meadow.Hardware;
+
+/// <summary>
+/// Represents a CAN extended exact acceptance filter.
+/// </summary>
+public class CanExtendedExactAcceptanceFilter : CanAcceptanceFilter
+{
+    /// <summary>
+    /// Gets the accepted identifier.
+    /// </summary>
+    public int AcceptID { get; }
+
+    /// <summary>
+    /// Initializes a new instance of the <see cref="CanExtendedExactAcceptanceFilter"/> class with the specified accepted identifier.
+    /// </summary>
+    /// <param name="acceptID">The accepted identifier.</param>
+    public CanExtendedExactAcceptanceFilter(short acceptID)
+    {
+        AcceptID = (short)(acceptID & 0x7ff);
+    }
+}

Source/Meadow.Contracts/Hardware/Contracts/PortsAndBuses/CAN/CanStandardExactAcceptanceFilter.cs

@@ -0,0 +1,21 @@
+namespace Meadow.Hardware;
+
+/// <summary>
+/// Represents a CAN standard exact acceptance filter.
+/// </summary>
+public class CanStandardExactAcceptanceFilter : CanAcceptanceFilter
+{
+    /// <summary>
+    /// Gets the accepted identifier.
+    /// </summary>
+    public short AcceptID { get; }
+
+    /// <summary>
+    /// Initializes a new instance of the <see cref="CanStandardExactAcceptanceFilter"/> class with the specified accepted identifier.
+    /// </summary>
+    /// <param name="acceptID">The accepted identifier.</param>
+    public CanStandardExactAcceptanceFilter(short acceptID)
+    {
+        AcceptID = (short)(acceptID & 0x7ff);
+    }
+}

Source/Meadow.Contracts/Hardware/Contracts/PortsAndBuses/CAN/CanStandardRangeAcceptanceFilter.cs

@@ -0,0 +1,55 @@
+namespace Meadow.Hardware;
+
+/// <summary>
+/// Represents a CAN extended range acceptance filter.
+/// </summary>
+public class CanExtendedRangeAcceptanceFilter : CanAcceptanceFilter
+{
+    /// <summary>
+    /// Gets the first (inclusive) accepted identifier in the range.
+    /// </summary>
+    public int FirstAcceptID { get; }
+
+    /// <summary>
+    /// Gets the last (inclusive) accepted identifier in the range.
+    /// </summary>
+    public int LastAcceptID { get; }
+
+    /// <summary>
+    /// Initializes a new instance of the <see cref="CanExtendedRangeAcceptanceFilter"/> class with the specified range of accepted identifiers.
+    /// </summary>
+    /// <param name="firstAcceptID">The first accepted identifier in the range.</param>
+    /// <param name="lastAcceptID">The last accepted identifier in the range.</param>
+    public CanExtendedRangeAcceptanceFilter(int firstAcceptID, int lastAcceptID)
+    {
+        FirstAcceptID = firstAcceptID;
+        LastAcceptID = lastAcceptID;
+    }
+}
+
+/// <summary>
+/// Represents a CAN standard range acceptance filter.
+/// </summary>
+public class CanStandardRangeAcceptanceFilter : CanAcceptanceFilter
+{
+    /// <summary>
+    /// Gets the first (inclusive) accepted identifier in the range.
+    /// </summary>
+    public short FirstAcceptID { get; }
+
+    /// <summary>
+    /// Gets the last (inclusive) accepted identifier in the range.
+    /// </summary>
+    public short LastAcceptID { get; }
+
+    /// <summary>
+    /// Initializes a new instance of the <see cref="CanStandardRangeAcceptanceFilter"/> class with the specified range of accepted identifiers.
+    /// </summary>
+    /// <param name="firstAcceptID">The first accepted identifier in the range.</param>
+    /// <param name="lastAcceptID">The last accepted identifier in the range.</param>
+    public CanStandardRangeAcceptanceFilter(short firstAcceptID, short lastAcceptID)
+    {
+        FirstAcceptID = (short)(firstAcceptID & 0x7ff);
+        LastAcceptID = (short)(lastAcceptID & 0x7ff);
+    }
+}

Source/Meadow.Contracts/Hardware/Contracts/PortsAndBuses/CAN/ICanBus.cs

@@ -7,6 +7,11 @@ namespace Meadow.Hardware;
 /// </summary>
 public interface ICanBus
 {
+    /// <summary>
+    /// Gets or sets the bus bit rate
+    /// </summary>
+    CanBitrate BitRate { get; set; }
+
     /// <summary>
     /// Occurs when a CAN frame is received.
     /// </summary>
@@ -31,14 +36,12 @@ public interface ICanBus
     ICanFrame? ReadFrame();
 
     /// <summary>
-    /// Sets the CAN filter.
+    /// Clears any data currently in the bus receive buffers
     /// </summary>
-    /// <param name="filter">The filter value.</param>
-    void SetFilter(int filter);
+    void ClearReceiveBuffers();
 
     /// <summary>
-    /// Sets the CAN mask.
+    /// The collection of message acceptance filters for the bus
     /// </summary>
-    /// <param name="filter">The mask value.</param>
-    void SetMask(int filter);
+    CanAcceptanceFilterCollection AcceptanceFilters { get; }
 }