Added LP55231 Support (#1763)

src/devices/Lp55231/Control1RegisterFlags.cs

+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+using System;
+
+namespace Iot.Device.Lp55231
+{
+    /// <summary>
+    /// Flags related to the REG_CNTRL1 register
+    /// </summary>
+    [Flags]
+    internal enum Control1RegisterFlags : byte
+    {
+        /// <summary>
+        /// Enable the Lp55231
+        /// </summary>
+        Enabled = 0x40
+    }
+}

src/devices/Lp55231/Lp55231.cs

+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+using System;
+using System.Device.I2c;
+using System.IO;
+using SixLabors.ImageSharp;
+using SixLabors.ImageSharp.PixelFormats;
+
+namespace Iot.Device.Lp55231
+{
+    /// <summary>
+    /// Lp55231 9 channel I2C PWM LED controller
+    /// </summary>
+    public class Lp55231 : IDisposable
+    {
+        /// <summary>
+        /// Default I2C address of Motor Hat
+        /// </summary>
+        public const int DefaultI2cAddress = 0x32;
+
+        /// <summary>
+        /// Gets the channel of the red element of the specific instance
+        /// </summary>
+        /// <param name="instance">The RGB instance (0-2)</param>
+        /// <returns>The channel number</returns>
+        internal static byte RedChannel(byte instance) => (byte)(6 + instance);
+
+        /// <summary>
+        /// Gets the channel of the green element of the specific instance
+        /// </summary>
+        /// <param name="instance">The RGB instance (0-2)</param>
+        /// <returns>The channel number</returns>
+        internal static byte GreenChannel(byte instance) => (byte)(instance * 2);
+
+        /// <summary>
+        /// Gets the channel of the blue element of the specific instance
+        /// </summary>
+        /// <param name="instance">The RGB instance (0-2)</param>
+        /// <returns>The channel number</returns>
+        internal static byte BlueChannel(byte instance) => (byte)(instance * 2 + 1);
+
+        private readonly Color[] _leds;
+        private I2cDevice _i2cDevice;
+
+        /// <summary>
+        /// Initializes a new instance of the <see cref="Lp55231"/> class with the specified <see cref="I2cDevice"/>.
+        /// </summary>
+        /// <param name="i2cDevice">The I2C device to use to communicate with the Lp55231.</param>
+        /// <remarks>
+        /// The default i2c address is 0x32.
+        /// </remarks>
+        public Lp55231(I2cDevice i2cDevice)
+        {
+            _i2cDevice = i2cDevice ?? throw new ArgumentNullException(nameof(i2cDevice));
+
+            _leds = new[]
+            {
+                Color.FromRgba(0, 0, 0, byte.MaxValue),
+                Color.FromRgba(0, 0, 0, byte.MaxValue),
+                Color.FromRgba(0, 0, 0, byte.MaxValue)
+            };
+        }
+
+        private byte ReadRegister(Register register)
+        {
+            _i2cDevice.WriteByte((byte)register);
+            return _i2cDevice.ReadByte();
+        }
+
+        private void WriteRegister(Register register, byte data)
+        {
+            Span<byte> bytes = stackalloc byte[2];
+            bytes[0] = (byte)register;
+            bytes[1] = data;
+            _i2cDevice.Write(bytes);
+        }
+
+        private void SetIntensity(byte index, byte value)
+        {
+            WriteRegister(Register.REG_D1_PWM + index, value);
+        }
+
+        /// <inheritdoc/>
+        public void Dispose()
+        {
+            _i2cDevice?.Dispose();
+            _i2cDevice = null!;
+        }
+
+        /// <summary>
+        /// Resets the Lp55231
+        /// </summary>
+        /// <remarks>
+        /// You should delay after calling this method
+        /// </remarks>
+        public void Reset()
+        {
+            try
+            {
+                WriteRegister(Register.REG_RESET, 0xFF);
+            }
+            catch (IOException)
+            {
+                // Resetting will prevent the expected ack resulting
+                // in an IOException. It's fine to swallow this.
+            }
+        }
+
+        /// <summary>
+        /// Gets/sets whether the Lp55231 is enabled.
+        /// </summary>
+        /// <remarks>
+        /// Setting this value will stop eny programs currently running.
+        /// </remarks>
+        public bool Enabled
+        {
+            get
+            {
+                var register = ReadRegister(Register.REG_CNTRL1);
+                return (register & (byte)Control1RegisterFlags.Enabled) > 0;
+            }
+
+            set
+            {
+                byte flags = value
+                    ? (byte)Control1RegisterFlags.Enabled
+                    : (byte)0x00;
+
+                WriteRegister(Register.REG_CNTRL1, flags);
+            }
+        }
+
+        /// <summary>
+        /// Gets/sets miscellaneous control flags
+        /// </summary>
+        public MiscFlags Misc
+        {
+            get
+            {
+                var flags = ReadRegister(Register.REG_MISC);
+                return (MiscFlags)flags;
+            }
+
+            set
+            {
+                var flags = (byte)value;
+                WriteRegister(Register.REG_MISC, flags);
+            }
+        }
+
+        /// <summary>
+        /// Gets or sets the <see cref="Color"/> of the LED at the specified <paramref name="index"/>.
+        /// </summary>
+        /// <param name="index">The index of the LED.</param>
+        /// <returns>The current <see cref="Color"/> of the LED.</returns>
+        /// <exception cref="ArgumentOutOfRangeException">Index must be between 0 and 2.</exception>
+        public Color this[byte index]
+        {
+            get
+            {
+                if (index < 0 || index > 2)
+                {
+                    throw new ArgumentOutOfRangeException(nameof(index));
+                }
+
+                return _leds[index];
+            }
+
+            set
+            {
+                if (index < 0 || index > 2)
+                {
+                    throw new ArgumentOutOfRangeException(nameof(index));
+                }
+
+                if (value != _leds[index])
+                {
+                    var color = value.ToPixel<Rgba32>();
+
+                    SetIntensity(RedChannel(index), color.R);
+                    SetIntensity(GreenChannel(index), color.G);
+                    SetIntensity(BlueChannel(index), color.B);
+
+                    _leds[index] = value;
+                }
+            }
+        }
+    }
+}

src/devices/Lp55231/Lp55231.csproj

+<Project Sdk="Microsoft.NET.Sdk">
+  <PropertyGroup>
+    <TargetFrameworks>$(DefaultBindingTfms)</TargetFrameworks>
+    <!--Disabling default items so samples source won't get build by the main library-->
+    <EnableDefaultItems>false</EnableDefaultItems>
+  </PropertyGroup>
+  <ItemGroup>
+    <Compile Include="*.cs" />
+    <None Include="README.md" />
+    <ProjectReference Include="..\Common\CommonHelpers.csproj" />
+  </ItemGroup>
+</Project>
\ No newline at end of file

src/devices/Lp55231/Lp55231.sln

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+EndProject
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src/devices/Lp55231/MiscFlags.cs

+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+using System;
+
+namespace Iot.Device.Lp55231
+{
+    /// <summary>
+    /// Flags related to the REG_MISC register
+    /// </summary>
+    [Flags]
+    public enum MiscFlags : byte
+    {
+        /// <summary>
+        /// Use internal clock
+        /// </summary>
+        ClockSourceSelection = 0b0000_0001,
+
+        /// <summary>
+        /// Use external clock
+        /// </summary>
+        ExternalClockDetection = 0b0000_0010,
+
+        /// <summary>
+        /// Enable PWM cycle power save
+        /// </summary>
+        PwmCyclePowersaveEnable = 0b0000_0100,
+
+        /// <summary>
+        /// Charge mode gain low bit
+        /// </summary>
+        ChargeModeGainLowBit = 0b0000_1000,
+
+        /// <summary>
+        /// Charge mode gain high bit
+        /// </summary>
+        ChargeModeGainHighBit = 0b0001_0000,
+
+        /// <summary>
+        /// Enable power save mode
+        /// </summary>
+        PowersaveModeEnable = 0b0010_0000,
+
+        /// <summary>
+        /// Enable auto address increment
+        /// </summary>
+        AddressAutoIncrementEnable = 0b0100_0000
+    }
+}

src/devices/Lp55231/README.md

+# Lp55231 - Nine-Channel RGB, White-LED Driver
+
+The Lp55231 is a I2C controlled, Nine-Channel RGB, White-LED Driver With Internal Program Memory and Integrated Charge Pump.
+
+## Documentation
+
+- [Texas Instruments](https://www.ti.com/product/LP55231)
+- [Sparkfun](https://www.sparkfun.com/products/13884)
+
+## Usage
+
+This driver currently provides just the fundamentals to drive RGB Leds. It does not currently support
+
+- Individual control of PWM channels
+- Setting LED drive current
+- Programming
+
+### RGB Leds
+
+The following example show how to use the RGB leds on the Sparkfun Lp55231 breakout board.
+
+```csharp
+var i2cDevice = I2cDevice.Create(new I2cConnectionSettings(1, Lp55231.DefaultI2cAddress));
+
+using (var device = new Lp55231(i2cDevice))
+{
+    device.Reset();
+
+    // Give the IC time to restart
+    Thread.Sleep(100);
+
+    device.Enabled = true;
+
+    device.Misc = MiscFlags.ClockSourceSelection
+                | MiscFlags.ExternalClockDetection
+                | MiscFlags.ChargeModeGainHighBit
+                | MiscFlags.AddressAutoIncrementEnable;
+                
+    ledDriver[0] = Color.FromArgb(0, 255, 0, 0);
+    ledDriver[1] = Color.FromArgb(0, 0, 255, 0);
+    ledDriver[2] = Color.FromArgb(0, 0, 0, 255);
+}
+```

src/devices/Lp55231/Register.cs

+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+namespace Iot.Device.Lp55231
+{
+    /// <summary>
+    /// Registers for the Lp55231 based on this reference: https://www.ti.com/lit/gpn/lp55231
+    /// </summary>
+    internal enum Register : byte
+    {
+        /// <summary/>
+        REG_CNTRL1 = 0x00,
+
+        /// <summary/>
+        REG_CNTRL2 = 0x01,
+
+        /// <summary/>
+        REG_RATIO_MSB = 0x02,
+
+        /// <summary/>
+        REG_RATIO_LSB = 0x03,
+
+        /// <summary/>
+        REG_OUTPUT_ONOFF_MSB = 0x04,
+
+        /// <summary/>
+        REG_OUTPUT_ONOFF_LSB = 0x05,
+
+        // Per LED control channels - fader channel assig, log dimming enable, temperature compensation
+
+        /// <summary/>
+        REG_D1_CTRL = 0x06,
+
+        /// <summary/>
+        REG_D2_CTRL = 0x07,
+
+        /// <summary/>
+        REG_D3_CTRL = 0x08,
+
+        /// <summary/>
+        REG_D4_CTRL = 0x09,
+
+        /// <summary/>
+        REG_D5_CTRL = 0x0a,
+
+        /// <summary/>
+        REG_D6_CTRL = 0x0b,
+
+        /// <summary/>
+        REG_D7_CTRL = 0x0c,
+
+        /// <summary/>
+        REG_D8_CTRL = 0x0d,
+
+        /// <summary/>
+        REG_D9_CTRL = 0x0e,
+
+        // Direct PWM control registers
+
+        /// <summary/>
+        REG_D1_PWM = 0x16,
+
+        /// <summary/>
+        REG_D2_PWM = 0x17,
+
+        /// <summary/>
+        REG_D3_PWM = 0x18,
+
+        /// <summary/>
+        REG_D4_PWM = 0x19,
+
+        /// <summary/>
+        REG_D5_PWM = 0x1a,
+
+        /// <summary/>
+        REG_D6_PWM = 0x1b,
+
+        /// <summary/>
+        REG_D7_PWM = 0x1c,
+
+        /// <summary/>
+        REG_D8_PWM = 0x1d,
+
+        /// <summary/>
+        REG_D9_PWM = 0x1e,
+
+        // Drive cuttent registers
+
+        /// <summary/>
+        REG_D1_I_CTL = 0x26,
+
+        /// <summary/>
+        REG_D2_I_CTL = 0x27,
+
+        /// <summary/>
+        REG_D3_I_CTL = 0x28,
+
+        /// <summary/>
+        REG_D4_I_CTL = 0x29,
+
+        /// <summary/>
+        REG_D5_I_CTL = 0x2a,
+
+        /// <summary/>
+        REG_D6_I_CTL = 0x2b,
+
+        /// <summary/>
+        REG_D7_I_CTL = 0x2c,
+
+        /// <summary/>
+        REG_D8_I_CTL = 0x2d,
+
+        /// <summary/>
+        REG_D9_I_CTL = 0x2e,
+
+        /// <summary/>
+        REG_MISC = 0x36,
+
+        /// <summary/>
+        REG_PC1 = 0x37,
+
+        /// <summary/>
+        REG_PC2 = 0x38,
+
+        /// <summary/>
+        REG_PC3 = 0x39,
+
+        /// <summary/>
+        REG_STATUS_IRQ = 0x3A,
+
+        /// <summary/>
+        REG_RESET = 0x3D,
+
+        /// <summary/>
+        REG_PROG1_START = 0x4C,
+
+        /// <summary/>
+        REG_PROG2_START = 0x4D,
+
+        /// <summary/>
+        REG_PROG3_START = 0x4E,
+
+        /// <summary/>
+        REG_PROG_PAGE_SEL = 0x4f,
+
+        // Memory is more confusing - there are 4 pages, sel by addr 4f
+
+        /// <summary/>
+        REG_PROG_MEM_BASE = 0x50,
+
+        // static const uint8_t REG_PROG_MEM_SIZE = 0x;//
+
+        /// <summary/>
+        REG_PROG_MEM_END = 0x6f,
+
+        /// <summary/>
+        REG_ENG1_MAP_MSB = 0x70,
+
+        /// <summary/>
+        REG_ENG1_MAP_LSB = 0x71,
+
+        /// <summary/>
+        REG_ENG2_MAP_MSB = 0x72,
+
+        /// <summary/>
+        REG_ENG2_MAP_LSB = 0x73,
+
+        /// <summary/>
+        REG_ENG3_MAP_MSB = 0x74,
+
+        /// <summary/>
+        REG_ENG3_MAP_LSB = 0x75,
+    }
+}

src/devices/Lp55231/category.txt

+display
+led
+pwm
\ No newline at end of file

src/devices/Lp55231/samples/Lp55231.Samples.csproj

+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <OutputType>Exe</OutputType>
+    <TargetFramework>$(DefaultSampleTfms)</TargetFramework>
+  </PropertyGroup>
+  
+  <ItemGroup>
+    <PackageReference Include="System.Drawing.Common" Version="$(SystemDrawingCommonPackageVersion)" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <ProjectReference Include="..\Lp55231.csproj" />
+  </ItemGroup>
+
+</Project>

src/devices/Lp55231/samples/Program.cs

+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+using System;
+using System.Device.I2c;
+using System.Threading;
+using Iot.Device.Lp55231;
+using SixLabors.ImageSharp;
+
+var i2cDevice = I2cDevice.Create(new I2cConnectionSettings(1, Lp55231.DefaultI2cAddress));
+
+using var ledDriver = new Lp55231(i2cDevice);
+
+ledDriver.Reset();
+
+Thread.Sleep(100);
+
+ledDriver.Enabled = true;
+
+ledDriver.Misc = MiscFlags.ClockSourceSelection
+               | MiscFlags.ExternalClockDetection
+               | MiscFlags.ChargeModeGainHighBit
+               | MiscFlags.AddressAutoIncrementEnable;
+
+ledDriver[0] = Color.FromRgba(255, 0, 0, byte.MaxValue);
+ledDriver[1] = Color.FromRgba(0, 255, 0, byte.MaxValue);
+ledDriver[2] = Color.FromRgba(0, 0, 255, byte.MaxValue);
+
+Console.WriteLine("Should be showing red, green, blue");