// MUNTS-0018 Raspberry Pi Tutorial I/O Board Definitions

// Copyright (C)2021-2024, Philip Munts dba Munts Technologies.
//
// Redistribution and use in source and binary forms, with or without
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//
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using IO.Objects.SimpleIO.Device;
using IO.Objects.SimpleIO.GPIO;
using IO.Objects.SimpleIO.Platforms;
using System.Collections.Generic;

namespace IO.Objects.SimpleIO.Platforms
{
    /// <summary>
    /// This class provides designators for I/O resources available on the
    /// <a href="http://tech.munts.com/manuals/MUNTS-0018.pdf">MUNTS-0018</a>
    /// Tutorial I/O Board.
    /// </summary>
    public static class MUNTS_0018
    {
        /// <summary>
        /// This class provides designators specific to the  64-Bit
        /// <a href="https://www.raspberrypi.com/products/raspberry-pi-zero-2-w">Raspberry Pi Zero 2 W</a>
        /// interface computer.
        /// </summary>
        /// <remarks>
        /// The following device tree overlay commands must be added to
        /// <c>/boot/config.txt</c>:
        /// <code>
        /// dtoverlay=anyspi,spi0-1,dev="microchip,mcp3204",speed=1000000
        /// dtoverlay=pwm-2chan,pin=12,func=4,pin2=19,func2=2
        /// </code>
        /// </remarks>
        public static class RaspberryPi
        {
            // On board LED

            /// <summary>
            /// GPIO pin <c>Designator</c> for the on-board LED <c>D1</c>.
            /// </summary>
            public static readonly Designator D1 =
                IO.Objects.SimpleIO.Platforms.RaspberryPi.GPIO26;

            // On board pushbutton switch

            /// <summary>
            /// GPIO pin <c>Designator</c> for the on-board momentary switch
            /// <c>SW1</c>.
            /// </summary>
            public static readonly Designator SW1 =
                IO.Objects.SimpleIO.Platforms.RaspberryPi.GPIO6;

            // Grove GPIO Connectors

            /// <summary>
            /// GPIO pin <c>Designator</c> for Digital I/O Grove Connector
            /// <c>J4</c> pin <c>D0</c>.
            /// </summary>
            public static readonly Designator J4D0 =
                IO.Objects.SimpleIO.Platforms.RaspberryPi.GPIO23;

            /// <summary>
            /// GPIO pin <c>Designator</c> for Digital I/O Grove Connector
            /// <c>J4</c> pin <c>D1</c>.
            /// </summary>
            public static readonly Designator J4D1 =
                IO.Objects.SimpleIO.Platforms.RaspberryPi.GPIO24;

            /// <summary>
            /// GPIO pin <c>Designator</c> for Digital I/O Grove Connector
            /// <c>J5</c> pin <c>D0</c>.
            /// </summary>
            public static readonly Designator J5D0 =
                IO.Objects.SimpleIO.Platforms.RaspberryPi.GPIO5;

            /// <summary>
            /// GPIO pin <c>Designator</c> for Digital I/O Grove Connector
            /// <c>J5</c> pin <c>D1</c>.
            /// </summary>
            public static readonly Designator J5D1 =
                IO.Objects.SimpleIO.Platforms.RaspberryPi.GPIO4;

            /// <summary>
            /// GPIO pin <c>Designator</c> for DC Motor Driver Grove Connector
            /// <c>J6</c> pin <c>D0</c>.
            /// </summary>
            /// <remarks>
            /// This GPIO pin is normally unusable because <c>GPIO12</c> is
            /// mapped to PWM output <c>PWM0</c>.
            /// </remarks>
            public static readonly Designator J6D0 =
                IO.Objects.SimpleIO.Platforms.RaspberryPi.GPIO12;

            /// <summary>
            /// GPIO pin <c>Designator</c> for DC Motor Driver Grove Connector
            /// <c>J6</c> pin <c>D1</c>.
            /// </summary>
            public static readonly Designator J6D1 =
                IO.Objects.SimpleIO.Platforms.RaspberryPi.GPIO13;

            /// <summary>
            /// GPIO pin <c>Designator</c> for DC Motor Driver Grove Connector
            /// <c>J7</c> pin <c>D0</c>.
            /// </summary>
            /// <remarks>
            /// This GPIO pin is normally unusable because <c>GPIO19</c> is
            /// mapped to PWM output <c>PWM1</c>.
            /// </remarks>
            public static readonly Designator J7D0 =
                IO.Objects.SimpleIO.Platforms.RaspberryPi.GPIO19;

            /// <summary>
            /// GPIO pin <c>Designator</c> for DC Motor Driver Grove Connector
            /// <c>J7</c> pin <c>D1</c>.
            /// </summary>
            public static readonly Designator J7D1 =
                IO.Objects.SimpleIO.Platforms.RaspberryPi.GPIO18;

            // Servo headers

            /// <summary>
            /// Servo position PWM output <c>Designator</c> for Servo Header
            /// <c>J2</c>.
            /// </summary>
            public static readonly Designator J2PWM =
                IO.Objects.SimpleIO.Platforms.RaspberryPi.PWM0;

            /// <summary>
            /// Servo position PWM output <c>Designator</c> for Servo Header
            /// <c>J3</c>.
            /// </summary>
            public static readonly Designator J3PWM =
                IO.Objects.SimpleIO.Platforms.RaspberryPi.PWM1;

            // DC motor control outputs (PWM and direction)

            /// <summary>
            /// Motor speed PWM output <c>Designator</c> for DC Motor Driver
            /// Grove Connector <c>J6</c>.
            /// </summary>
            public static readonly Designator J6PWM =
                IO.Objects.SimpleIO.Platforms.RaspberryPi.PWM0;

            /// <summary>
            /// Motor direction GPIO output pin <c>Designator</c> for DC Motor
            /// Driver Grove Connector <c>J6</c>.
            /// </summary>
            public static readonly Designator J6DIR = J6D1;

            /// <summary>
            /// Motor speed PWM output <c>Designator</c> for DC Motor Driver
            /// Grove Connector <c>J6</c> as configured for the
            /// <a href="https://www.cytron.io/p-13amp-6v-30v-dc-motor-driver">Cytron MD13S</a>
            /// Grove motor driver board.
            /// </summary>
            /// <remarks>
            /// The speed and direction pins need to be swapped for the MD13S.
            /// This requires using the <c>MUNTS-0018-MD13S</c> device tree
            /// overlay instead of <c>MUNTS-0018</c> to arrange the Raspberry
            /// Pi expansion bus PWM and GPIO pins properly for the MD13S.
            /// </remarks>
            public static readonly Designator J6PWM_MD13S =
                IO.Objects.SimpleIO.Platforms.RaspberryPi.PWM1;

            /// <summary>
            /// Motor direction GPIO output pin <c>Designator</c> for DC Motor
            /// Driver Grove Connector<c>J6</c> as configured for the
            /// <a href="https://www.cytron.io/p-13amp-6v-30v-dc-motor-driver">Cytron MD13S</a>
            /// Grove motor driver board.
            /// </summary>
            /// <remarks>
            /// The speed and direction pins need to be swapped for the MD13S.
            /// This requires using the <c>MUNTS-0018-MD13S</c> device tree
            /// overlay instead of <c>MUNTS-0018</c> to arrange the Raspberry
            /// Pi expansion bus PWM and GPIO pins properly for the MD13S.
            /// </remarks>
            public static readonly Designator J6DIR_MD13S = J6D0;

            /// <summary>
            /// Motor speed PWM output <c>Designator</c> for DC Motor Driver
            /// Grove Connector <c>J7</c>.
            /// </summary>
            public static readonly Designator J7PWM =
                IO.Objects.SimpleIO.Platforms.RaspberryPi.PWM1;

            /// <summary>
            /// Motor direction GPIO output pin <c>Designator</c> for DC Motor
            /// Driver Grove Connector <c>J6</c>.
            /// </summary>
            public static readonly Designator J7DIR = J7D1;

            /// <summary>
            /// Motor speed PWM output <c>Designator</c> for DC Motor Driver
            /// Grove Connector <c>J7</c> as configured for the
            /// <a href="https://www.cytron.io/p-13amp-6v-30v-dc-motor-driver">Cytron MD13S</a>
            /// Grove motor driver board.
            /// </summary>
            /// <remarks>
            /// The speed and direction pins need to be swapped for the MD13S.
            /// This requires using the <c>MUNTS-0018-MD13S</c> device tree
            /// overlay instead of <c>MUNTS-0018</c> to arrange the Raspberry
            /// Pi expansion bus PWM and GPIO pins properly for the MD13S.
            /// </remarks>
            public static readonly Designator J7PWM_MD13S =
                IO.Objects.SimpleIO.Platforms.RaspberryPi.PWM0;

            /// <summary>
            /// Motor direction GPIO output pin <c>Designator</c> for DC Motor
            /// Driver Grove Connector<c>J7</c> as configured for the
            /// <a href="https://www.cytron.io/p-13amp-6v-30v-dc-motor-driver">Cytron MD13S</a>
            /// Grove motor driver board.
            /// </summary>
            /// <remarks>
            /// The speed and direction pins need to be swapped for the MD13S.
            /// This requires using the <c>MUNTS-0018-MD13S</c> device tree
            /// overlay instead of <c>MUNTS-0018</c> to arrange the Raspberry
            /// Pi expansion bus PWM and GPIO pins properly for the MD13S.
            /// </remarks>
            public static readonly Designator J7DIR_MD13S = J7D0;

            // I2C buses

            /// <summary>
            /// I<sup>2</sup>C bus <c>Designator</c> for <c>/dev/i2c-1</c>
            /// on I<sup>2</sup>C Grove Connector <c>J9</c>.
            /// </summary>
            public static readonly Designator J9I2C =
                IO.Objects.SimpleIO.Platforms.RaspberryPi.I2C1;

            // Analog inputs (on board MCP3204)

            /// <summary>
            /// Analog input <c>Designator</c> for Analog Input Grove Connector
            /// <c>J10</c> pin <c>A0</c> (MCP3204 input <c>CH2</c>.
            /// </summary>
            public static readonly Designator J10A0 = new Designator(0, 2);

            /// <summary>
            /// Analog input <c>Designator</c> for Analog Input Grove Connector
            /// <c>J10</c> pin <c>A1</c> (MCP3204 input <c>CH3</c>.
            /// </summary>
            public static readonly Designator J10A1 = new Designator(0, 3);

            /// <summary>
            /// Analog input <c>Designator</c> for Analog Input Grove Connector
            /// <c>J11</c> pin <c>A0</c> (MCP3204 input <c>CH0</c>.
            /// </summary>
            public static readonly Designator J11A0 = new Designator(0, 0);

            /// <summary>
            /// Analog input <c>Designator</c> for Analog Input Grove Connector
            /// <c>J11</c> pin <c>A1</c> (MCP3204 input <c>CH1</c>.
            /// </summary>
            public static readonly Designator J11A1 = new Designator(0, 1);

            // Create lists of valid designators, to be used for error checking
            // in the factory functions below.

            private static readonly List<Designator> ValidAnalogInputs =
                new List<Designator>(new[] { J10A0, J10A1, J11A0, J11A1 });

            private static readonly List<Designator> ValidGPIOPins =
                new List<Designator>(new[] { J4D0, J4D1, J5D0, J5D1, J6D0, J6D1, J7D0, J7D1 });

            private static readonly List<Designator> ValidMotorSpeedOutputs =
                new List<Designator>(new[] { J6PWM, J7PWM });

            private static readonly List<Designator> ValidMotorDirectionOutputs =
                new List<Designator>(new[] { J6DIR, J7DIR });

            private static readonly List<Designator> ValidServoOutputs =
                new List<Designator>(new[] { J2PWM, J3PWM });

            /// <summary>
            /// Analog input object factory for the on-board analog inputs at
            /// connectors <c>J10</c> and <c>J11</c>.
            /// </summary>
            /// <param name="desg">Device designator for one of the on-board
            /// analog inputs (<c>J10A0</c>, <c>J10A1</c>, <c>J11A0</c>, or
            /// <c>J11A1</c>).</param>
            /// <returns>Analog input object.</returns>
            public static IO.Interfaces.ADC.Voltage AnalogInputFactory(Designator desg)
            {
                // Validate analog input designator

                if (!ValidAnalogInputs.Contains(desg))
                {
                    throw new System.ArgumentException("Invalid analog input designator.");
                }

                // Return analog input instance

                return new IO.Interfaces.ADC.Input(new IO.Objects.SimpleIO.ADC.Sample(desg, 12), 3.3);
            }

            /// <summary>
            /// GPIO pin object factory for the on-board button switch at <c>SW1</c>.
            /// </summary>
            /// <param name="edge">Interrupt edge setting.</param>
            /// <returns>GPIO input pin object.</returns>
            public static IO.Interfaces.GPIO.Pin ButtonInputFactory(IO.Objects.SimpleIO.GPIO.Edge edge = IO.Objects.SimpleIO.GPIO.Edge.None)
            {
                return new IO.Objects.SimpleIO.GPIO.Pin(SW1, IO.Interfaces.GPIO.Direction.Input, false, IO.Objects.SimpleIO.GPIO.Driver.PushPull, edge);
            }

            /// <summary>
            /// GPIO pin object factory for the on-board LED at <c>D1</c>.
            /// </summary>
            /// <param name="state">Initial GPIO output state.</param>
            /// <returns>GPIO output pin object.</returns>
            public static IO.Interfaces.GPIO.Pin LEDOutputFactory(bool state = false)
            {
                return new IO.Objects.SimpleIO.GPIO.Pin(D1, IO.Interfaces.GPIO.Direction.Output, state);
            }

            /// <summary>
            /// GPIO pin object factory for GPIO pins at connectors <c>J4</c> to
            /// <c>J7</c>.
            /// </summary>
            /// <param name="desg">Device designator for one of the on-board GPIO
            /// pins (<c>J4D0</c> to <c>J7D1</c>.</param>
            /// <param name="dir">Data direction.</param>
            /// <param name="state">Initial GPIO output state.</param>
            /// <param name="driver">Output driver setting.</param>
            /// <param name="edge">Interrupt edge setting.</param>
            /// <param name="polarity">Polarity setting.</param>
            /// <returns>GPIO pin object.</returns>
            public static IO.Interfaces.GPIO.Pin GPIOPinFactory(Designator desg,
                IO.Interfaces.GPIO.Direction dir, bool state = false,
                Driver driver = Driver.PushPull, Edge edge = Edge.None,
                Polarity polarity = Polarity.ActiveHigh)
            {
                // Validate the GPIO pin designator

                if (!ValidGPIOPins.Contains(desg))
                {
                    throw new System.ArgumentException("Invalid GPIO pin designator.");
                }

                // Return GPIO pin instance

                return new IO.Objects.SimpleIO.GPIO.Pin(desg, dir, state, driver, edge, polarity);
            }

            /// <summary>
            /// I<sup>2</sup>C bus object factory for the on-board I<sup>2</sup>C
            /// bus at connector <c>J9</c>.
            /// </summary>
            /// <returns>I<sup>2</sup>C bus object.</returns>
            public static IO.Interfaces.I2C.Bus I2CBusFactory()
            {
                return new IO.Objects.SimpleIO.I2C.Bus(J9I2C);
            }

            /// <summary>
            /// Motor output object factory for the on-board motor outputs
            /// at connectors <c>J6</c> and <c>J7</c>.
            /// </summary>
            /// <param name="speed">Device designator for the motor speed PWM
            /// output (<c>J6PWM</c> or <c>J7PWM</c>).</param>
            /// <param name="direction">Device designator for the motor direction
            /// GPIO output (<c>J6DIR</c> or <c>J7DIR</c>).</param>
            /// <param name="frequency">PWM pulse frequency.</param>
            /// <param name="velocity">Initial motor velocity.</param>
            /// <returns>Motor output object.</returns>
            public static IO.Interfaces.Motor.Output MotorOutputFactory(Designator speed,
                Designator direction, int frequency, double velocity = 0.0)
            {
                // Validate the PWM output designator

                if (!ValidMotorSpeedOutputs.Contains(speed))
                {
                    throw new System.ArgumentException("Invalid PWM output designator.");
                }

                // Validate the GPIO output designator

                if (!ValidMotorDirectionOutputs.Contains(direction))
                {
                    throw new System.ArgumentException("Invalid GPIO output designator.");
                }

                IO.Interfaces.PWM.Output S = new IO.Objects.SimpleIO.PWM.Output(speed, frequency);
                IO.Interfaces.GPIO.Pin D = new IO.Objects.SimpleIO.GPIO.Pin(direction, IO.Interfaces.GPIO.Direction.Output);

                return new IO.Objects.Motor.PWM.Output(D, S, velocity);
            }

            /// <summary>
            /// Servo output object factory for the on-board servo outputs
            /// at headers <c>J2</c> and <c>J3</c>.
            /// </summary>
            /// <param name="desg">Device designator for one of the on-board
            /// PWM outputs (<c>J2PWM</c> or <c>J3PWM</c>).</param>
            /// <param name="frequency">PWM pulse frequency.  Ordinary analog
            /// servos operate best at 50 Hz.</param>
            /// <returns>Servo output object.</returns>
            public static IO.Interfaces.Servo.Output ServoOutputFactory(Designator desg, int frequency = 50)
            {
                // Validate the servo output designator

                if (!ValidServoOutputs.Contains(desg))
                {
                    throw new System.ArgumentException("Invalid servo output designator.");
                }

                // Return servo output instance

                return new IO.Objects.SimpleIO.Servo.Output(desg, frequency);
            }
        }

        /// <summary>
        /// This class provides designators specific to the 64-Bit
        /// <a href="https://www.raspberrypi.com/products/raspberry-pi-zero-2-w">Orange Pi Zero 2 W</a>
        /// interface computer.
        /// </summary>
        /// <remarks>
        /// The Orange Pi Zero 2 W does not route PWM signals to <c>GPIO18</c>
        /// or <c>GPIO19</c>, so servo header <c>J2</c> and PWM Grove socket
        /// <c>J7</c> are not usable except as extro GPIO pins.
        /// </remarks>
        public static class OrangePiZero2W
        {
            // On board LED

            /// <summary>
            /// GPIO pin <c>Designator</c> for the on-board LED <c>D1</c>.
            /// </summary>
            public static readonly Designator D1 = OrangePiZero2W_RaspberryPi.GPIO26;

            // On board pushbutton switch

            /// <summary>
            /// GPIO pin <c>Designator</c> for the on-board momentary switch
            /// <c>SW1</c>.
            /// </summary>
            public static readonly Designator SW1 = OrangePiZero2W_RaspberryPi.GPIO6;

            // Grove GPIO Connectors

            /// <summary>
            /// GPIO pin <c>Designator</c> for Digital I/O Grove Connector
            /// <c>J4</c> pin <c>D0</c>.
            /// </summary>
            public static readonly Designator J4D0 = OrangePiZero2W_RaspberryPi.GPIO23;

            /// <summary>
            /// GPIO pin <c>Designator</c> for Digital I/O Grove Connector
            /// <c>J4</c> pin <c>D1</c>.
            /// </summary>
            public static readonly Designator J4D1 = OrangePiZero2W_RaspberryPi.GPIO24;

            /// <summary>
            /// GPIO pin <c>Designator</c> for Digital I/O Grove Connector
            /// <c>J5</c> pin <c>D0</c>.
            /// </summary>
            public static readonly Designator J5D0 = OrangePiZero2W_RaspberryPi.GPIO5;

            /// <summary>
            /// GPIO pin <c>Designator</c> for Digital I/O Grove Connector
            /// <c>J5</c> pin <c>D1</c>.
            /// </summary>
            public static readonly Designator J5D1 = OrangePiZero2W_RaspberryPi.GPIO4;

            /// <summary>
            /// GPIO pin <c>Designator</c> for DC Motor Driver Grove Connector
            /// <c>J6</c> pin <c>D0</c>.
            /// </summary>
            /// <remarks>
            /// This GPIO pin is normally unusable because it is configured as a
            /// motor speed control PWM output.
            /// </remarks>
            public static readonly Designator J6D0 = OrangePiZero2W_RaspberryPi.GPIO12;

            /// <summary>
            /// GPIO pin <c>Designator</c> for DC Motor Driver Grove Connector
            /// <c>J6</c> pin <c>D1</c>.
            /// </summary>
            /// <remarks>
            /// This GPIO pin is normally unusable because it is configured as a
            /// motor direction control GPIO output.
            /// </remarks>
            public static readonly Designator J6D1 = OrangePiZero2W_RaspberryPi.GPIO13;

            /// <summary>
            /// GPIO pin <c>Designator</c> for DC Motor Driver Grove Connector
            /// <c>J7</c> pin <c>D0</c>.
            /// </summary>
            /// <remarks>
            /// Unlike the Raspberry Pi, the Orange Pi Zero 2 W cannot route a
            /// PWM output to this pin.
            /// </remarks>
            public static readonly Designator J7D0 = OrangePiZero2W_RaspberryPi.GPIO19;

            /// <summary>
            /// GPIO pin <c>Designator</c> for DC Motor Driver Grove Connector
            /// <c>J7</c> pin <c>D1</c>.
            /// </summary>
            /// <remarks>
            /// Unlike the Raspberry Pi, the Orange Pi Zero 2 W cannot route a
            /// PWM output to this pin.
            /// </remarks>
            public static readonly Designator J7D1 = OrangePiZero2W_RaspberryPi.GPIO18;

            // Servo headers

            /// <summary>
            /// PWM output <c>Designator</c> for Servo Header <c>J2</c>.
            /// </summary>
            public static readonly Designator J2PWM = OrangePiZero2W_RaspberryPi.PWM0;

            // DC motor control outputs (PWM and direction)

            /// <summary>
            /// Motor speed PWM output <c>Designator</c> for DC Motor Driver
            /// Grove Connector <c>J6</c>.
            /// </summary>
            public static readonly Designator J6PWM = OrangePiZero2W_RaspberryPi.PWM0;

            /// <summary>
            /// Motor direction GPIO output pin <c>Designator</c> for DC Motor
            /// Driver Grove Connector <c>J6</c>.
            /// </summary>
            public static readonly Designator J6DIR = J6D1;

            /// <summary>
            /// Motor speed PWM output <c>Designator</c> for DC Motor Driver
            /// Grove Connector <c>J6</c> as configured for the
            /// <a href="https://www.cytron.io/p-13amp-6v-30v-dc-motor-driver">Cytron MD13S</a>
            /// Grove motor driver board.
            /// </summary>
            public static readonly Designator J6PWM_MD13S = OrangePiZero2W_RaspberryPi.PWM1;

            /// <summary>
            /// Motor direction GPIO output pin <c>Designator</c> for DC Motor
            /// Driver Grove Connector<c>J6</c> as configured for the
            /// <a href="https://www.cytron.io/p-13amp-6v-30v-dc-motor-driver">Cytron MD13S</a>
            /// Grove motor driver board.
            /// </summary>
            public static readonly Designator J6DIR_MD13S = J6D0;

            // I2C buses

            /// <summary>
            /// I<sup>2</sup>C bus <c>Designator</c> for I<sup>2</sup>C Grove
            /// Connector <c>J9</c>.
            /// </summary>
            public static readonly Designator J9I2C = OrangePiZero2W_RaspberryPi.I2C1;

            // Analog inputs (on board MCP3204)

            /// <summary>
            /// Analog input <c>Designator</c> for Analog Input Grove Connector
            /// <c>J10</c> pin <c>A0</c> (MCP3204 input <c>CH2</c>.
            /// </summary>
            public static readonly Designator J10A0 = new Designator(0, 2);

            /// <summary>
            /// Analog input <c>Designator</c> for Analog Input Grove Connector
            /// <c>J10</c> pin <c>A1</c> (MCP3204 input <c>CH3</c>.
            /// </summary>
            public static readonly Designator J10A1 = new Designator(0, 3);

            /// <summary>
            /// Analog input <c>Designator</c> for Analog Input Grove Connector
            /// <c>J11</c> pin <c>A0</c> (MCP3204 input <c>CH0</c>.
            /// </summary>
            public static readonly Designator J11A0 = new Designator(0, 0);

            /// <summary>
            /// Analog input <c>Designator</c> for Analog Input Grove Connector
            /// <c>J11</c> pin <c>A1</c> (MCP3204 input <c>CH1</c>.
            /// </summary>
            public static readonly Designator J11A1 = new Designator(0, 1);

            // Create lists of valid designators, to be used for error checking
            // in the factory functions below.

            private static readonly List<Designator> ValidAnalogInputs =
                new List<Designator>(new[] { J10A0, J10A1, J11A0, J11A1 });

            private static readonly List<Designator> ValidGPIOPins =
                new List<Designator>(new[] { J4D0, J4D1, J5D0, J5D1, J6D0, J6D1, J7D0, J7D1 });

            private static readonly List<Designator> ValidMotorSpeedOutputs =
                new List<Designator>(new[] { J6PWM, J6PWM_MD13S });

            private static readonly List<Designator> ValidMotorDirectionOutputs =
                new List<Designator>(new[] { J6DIR, J6DIR_MD13S });

            private static readonly List<Designator> ValidServoOutputs =
                new List<Designator>(new[] { J2PWM });

            /// <summary>
            /// Analog input object factory for the on-board analog inputs at
            /// connectors <c>J10</c> and <c>J11</c>.
            /// </summary>
            /// <param name="desg">Device designator for one of the on-board
            /// analog inputs (<c>J10A0</c>, <c>J10A1</c>, <c>J11A0</c>, or
            /// <c>J11A1</c>).</param>
            /// <returns>Analog input object.</returns>
            public static IO.Interfaces.ADC.Voltage AnalogInputFactory(Designator desg)
            {
                // Validate analog input designator

                if (!ValidAnalogInputs.Contains(desg))
                {
                    throw new System.ArgumentException("Invalid analog input designator.");
                }

                // Return analog input instance

                return new IO.Interfaces.ADC.Input(new IO.Objects.SimpleIO.ADC.Sample(desg, 12), 3.3);
            }

            /// <summary>
            /// GPIO pin object factory for the on-board button switch at <c>SW1</c>.
            /// </summary>
            /// <param name="edge">Interrupt edge setting.</param>
            /// <returns>GPIO input pin object.</returns>
            public static IO.Interfaces.GPIO.Pin ButtonInputFactory(IO.Objects.SimpleIO.GPIO.Edge edge = IO.Objects.SimpleIO.GPIO.Edge.None)
            {
                // Return GPIO pin instance

                return new IO.Objects.SimpleIO.GPIO.Pin(SW1, IO.Interfaces.GPIO.Direction.Input, false, IO.Objects.SimpleIO.GPIO.Driver.PushPull, edge);
            }

            /// <summary>
            /// GPIO pin object factory for the on-board LED at <c>D1</c>.
            /// </summary>
            /// <param name="state">Initial GPIO output state.</param>
            /// <returns>GPIO output pin object.</returns>
            public static IO.Interfaces.GPIO.Pin LEDOutputFactory(bool state = false)
            {
                // Return GPIO pin instance

                return new IO.Objects.SimpleIO.GPIO.Pin(D1, IO.Interfaces.GPIO.Direction.Output, state);
            }

            /// <summary>
            /// GPIO pin object factory for GPIO pins at connectors <c>J4</c> to
            /// <c>J7</c>.
            /// </summary>
            /// <param name="desg">Device designator for one of the on-board GPIO
            /// pins (<c>J4D0</c> to <c>J7D1</c>.</param>
            /// <param name="dir">Data direction.</param>
            /// <param name="state">Initial GPIO output state.</param>
            /// <param name="driver">Output driver setting.</param>
            /// <param name="edge">Interrupt edge setting.</param>
            /// <param name="polarity">Polarity setting.</param>
            /// <returns>GPIO pin object.</returns>
            public static IO.Interfaces.GPIO.Pin GPIOPinFactory(Designator desg,
                IO.Interfaces.GPIO.Direction dir, bool state = false,
                Driver driver = Driver.PushPull, Edge edge = Edge.None,
                Polarity polarity = Polarity.ActiveHigh)
            {
                // Validate the GPIO pin designator

                if (!ValidGPIOPins.Contains(desg))
                {
                    throw new System.ArgumentException("Invalid GPIO pin designator.");
                }

                // Return GPIO pin instance

                return new IO.Objects.SimpleIO.GPIO.Pin(desg, dir, state, driver, edge, polarity);
            }

            /// <summary>
            /// I<sup>2</sup>C bus object factory for the on-board I<sup>2</sup>C
            /// bus at connector <c>J9</c>.
            /// </summary>
            /// <returns>I<sup>2</sup>C bus object.</returns>
            public static IO.Interfaces.I2C.Bus I2CBusFactory()
            {
                return new IO.Objects.SimpleIO.I2C.Bus(J9I2C);
            }

            /// <summary>
            /// Motor output object factory for the on-board motor output
            /// at connector <c>J6</c>.
            /// </summary>
            /// <param name="speed">Device designator for the motor speed PWM
            /// output (<c>J6PWM</c>).</param>
            /// <param name="direction">Device designator for the motor direction
            /// GPIO output (<c>J6DIR</c>).</param>
            /// <param name="frequency">PWM pulse frequency.</param>
            /// <param name="velocity">Initial motor velocity.</param>
            /// <returns>Motor output object.</returns>
            public static IO.Interfaces.Motor.Output MotorOutputFactory(Designator speed,
                Designator direction, int frequency, double velocity = 0.0)
            {
                // Validate the PWM output designator

                if (!ValidMotorSpeedOutputs.Contains(speed))
                {
                    throw new System.ArgumentException("Invalid PWM output designator.");
                }

                // Validate the GPIO output designator

                if (!ValidMotorDirectionOutputs.Contains(direction))
                {
                    throw new System.ArgumentException("Invalid GPIO output designator.");
                }

                IO.Interfaces.PWM.Output S = new IO.Objects.SimpleIO.PWM.Output(speed, frequency);
                IO.Interfaces.GPIO.Pin D = new IO.Objects.SimpleIO.GPIO.Pin(direction, IO.Interfaces.GPIO.Direction.Output);

                return new IO.Objects.Motor.PWM.Output(D, S, velocity);
            }

            /// <summary>
            /// Servo output object factory for the on-board servo output
            /// at header <c>J2</c>.
            /// </summary>
            /// <param name="desg">Device designator for one of the on-board
            /// PWM outputs (<c>J2PWM</c>).</param>
            /// <param name="frequency">PWM pulse frequency.  Ordinary analog
            /// servos operate best at 50 Hz.</param>
            /// <returns>Servo output object.</returns>
            public static IO.Interfaces.Servo.Output ServoOutputFactory(Designator desg, int frequency = 50)
            {
                // Validate the servo output designator

                if (!ValidServoOutputs.Contains(desg))
                {
                    throw new System.ArgumentException("Invalid servo output designator.");
                }

                // Return servo output instance

                return new IO.Objects.SimpleIO.Servo.Output(desg, frequency);
            }
        }
    }
}