Refactor arduino interface to avoid event callback

.git-blame-ignore-revs

@@ -5,4 +5,8 @@ e6f499ad9c78eff87c57ded6ea620fccb255d691
 e12cd15478ef4dd7cc2a391ae74d877f33acee97
 
 # Ensure unix portability of uri launcher
-a949f77d92437690840a24857f421c0f47161d43
+a949f77d92437690840a24857f421c0f47161d43
+
+# Move arduino package into separate repository
+1804cdb10530babc3146f9c07bc7d23a877a93f5
+1a60ab3cd625cb89e29531895efdd96936c2c271

Bonsai.Arduino/AnalogInput.cs

@@ -0,0 +1,39 @@
+using System;
+using System.ComponentModel;
+
+namespace Bonsai.Arduino
+{
+    /// <summary>
+    /// Represents an operator that generates a sequence of digitized analog readings
+    /// from the specified Arduino input pin.
+    /// </summary>
+    [DefaultProperty(nameof(Pin))]
+    [Description("Generates a sequence of digitized analog readings from the specified Arduino input pin.")]
+    public class AnalogInput : Source<int>
+    {
+        /// <summary>
+        /// Gets or sets the name of the serial port used to communicate with the Arduino.
+        /// </summary>
+        [TypeConverter(typeof(PortNameConverter))]
+        [Description("The name of the serial port used to communicate with the Arduino.")]
+        public string PortName { get; set; }
+
+        /// <summary>
+        /// Gets or sets the analog input pin number from which to take readings.
+        /// </summary>
+        [Description("The analog input pin number from which to take readings.")]
+        public int Pin { get; set; }
+
+        /// <summary>
+        /// Generates an observable sequence of digitized analog values. 
+        /// </summary>
+        /// <returns>
+        /// A sequence of <see cref="int"/> values that report the digitized analog
+        /// readings from the specified Arduino analog input pin.
+        /// </returns>
+        public override IObservable<int> Generate()
+        {
+            return ObservableArduino.AnalogInput(PortName, Pin);
+        }
+    }
+}

Bonsai.Arduino/AnalogInputReceivedEventArgs.cs

@@ -0,0 +1,32 @@
+using System;
+
+namespace Bonsai.Arduino
+{
+    /// <summary>
+    /// Provides data for the <see cref="Arduino.AnalogInputReceived"/> event.
+    /// </summary>
+    public class AnalogInputReceivedEventArgs : EventArgs
+    {
+        /// <summary>
+        /// Initializes a new instance of the <see cref="AnalogInputReceivedEventArgs"/>
+        /// class using the pin number and analog value received in the analog input message.
+        /// </summary>
+        /// <param name="pin">The pin number from which the analog value was sampled.</param>
+        /// <param name="value">The digitized analog value.</param>
+        public AnalogInputReceivedEventArgs(int pin, int value)
+        {
+            Pin = pin;
+            Value = value;
+        }
+
+        /// <summary>
+        /// Gets the pin number from which the analog value was sampled.
+        /// </summary>
+        public int Pin { get; private set; }
+
+        /// <summary>
+        /// Gets the digitized analog value.
+        /// </summary>
+        public int Value { get; private set; }
+    }
+}

Bonsai.Arduino/AnalogOutput.cs

@@ -0,0 +1,61 @@
+using System;
+using System.ComponentModel;
+using System.Reactive.Linq;
+using System.Threading.Tasks;
+
+namespace Bonsai.Arduino
+{
+    /// <summary>
+    /// Represents an operator that writes the sequence of numerical values to the
+    /// specified Arduino output pin using PWM.
+    /// </summary>
+    [DefaultProperty(nameof(Pin))]
+    [Description("Writes the sequence of numerical values to the specified Arduino output pin using PWM.")]
+    public class AnalogOutput : Sink<int>
+    {
+        /// <summary>
+        /// Gets or sets the name of the serial port used to communicate with the Arduino.
+        /// </summary>
+        [TypeConverter(typeof(PortNameConverter))]
+        [Description("The name of the serial port used to communicate with the Arduino.")]
+        public string PortName { get; set; }
+
+        /// <summary>
+        /// Gets or sets the digital output (PWM) pin number on which to write values.
+        /// </summary>
+        [Description("The digital output (PWM) pin number on which to write values.")]
+        public int Pin { get; set; }
+
+        /// <summary>
+        /// Writes a sequence of <see cref="int"/> values to the specified Arduino output pin using PWM.
+        /// </summary>
+        /// <param name="source">
+        /// A sequence of <see cref="int"/> values to write into the specified Arduino output pin.
+        /// </param>
+        /// <returns>
+        /// A sequence of the <see cref="int"/> values which have been written into the Arduino
+        /// output pin.
+        /// </returns>
+        /// <remarks>
+        /// This operator only subscribes to the <paramref name="source"/> sequence after initializing
+        /// the connection to the Arduino and configuring the output pin mode to PWM.
+        /// </remarks>
+        public override IObservable<int> Process(IObservable<int> source)
+        {
+            return Observable.Using(
+                cancellationToken => ArduinoManager.ReserveConnectionAsync(PortName),
+                (connection, cancellationToken) =>
+                {
+                    var pin = Pin;
+                    connection.Arduino.PinMode(pin, PinMode.Pwm);
+                    return Task.FromResult(source.Do(value =>
+                    {
+                        lock (connection.Arduino)
+                        {
+                            connection.Arduino.AnalogWrite(pin, value);
+                        }
+                    }));
+                });
+        }
+    }
+}