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Adding static constructor from pin (#1)
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‎README.md‎

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| System.Device.Pwm | [![Build Status](https://dev.azure.com/nanoframework/System.Device.Pwm/_apis/build/status/nanoframework.System.Device.Pwm?branchName=develop)](https://dev.azure.com/nanoframework/System.Device.Pwm/_build/latest?definitionId=77&branchName=main) | [![NuGet](https://img.shields.io/nuget/v/nanoFramework.System.Device.Pwm.svg?label=NuGet&style=flat&logo=nuget)](https://www.nuget.org/packages/nanoFramework.System.Device.Pwm/) |
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| System.Device.Pwm (preview) | [![Build Status](https://dev.azure.com/nanoframework/System.Device.Pwm/_apis/build/status/nanoframework.System.Device.Pwm?branchName=develop)](https://dev.azure.com/nanoframework/System.Device.Pwm/_build/latest?definitionId=77&branchName=develop) | [![NuGet](https://img.shields.io/nuget/vpre/nanoFramework.System.Device.Pwm.svg?label=NuGet&style=flat&logo=nuget)](https://www.nuget.org/packages/nanoFramework.System.Device.Pwm/) |
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## Usage
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You can create a PWM channel from a pin number, this is the recommended way. Keep in mind, you will have to allocate the pin in the case of ESP32 and make sure your pin is PWM enabled for STM32 devices.
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```csharp
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// Case of ESP32, you need to set the pin function, in this example PWM3 for pin 18:
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Configuration.SetPinFunction(18, DeviceFunction.PWM3);
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PwmChannel pwmPin = PwmChannel.CreateFromPin(18, 40000);
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// You can check then if it has created a valid one:
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if (pwmPin != null)
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{
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// You do have a valid one
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}
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```
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### Duty cycle
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You can adjust the duty cycle by using the property:
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```csharp
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pwmPin.DutyCycle = 0.42;
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```
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The duty cycle goes from 0.0 to 1.0.
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### Frequency
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It is recommended to setup the frequency when creating the PWM Channel. You can technically change it at any time but keep in mind some platform may not behave properly when adjusting this element.
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### Advance PwmChannel creation
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You can as well, if you know the chip/timer Id and the channel use the create function:
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```csharp
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PwmChannel pwmPin = new(1, 2, 40000, 0.5);
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```
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This is only recommended for advance users.
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### Other considerations
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PWM precision may vary from platform to platform. It is highly recommended to check what precision can be achieved, either with the frequency, either with the duty cycle.
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## Feedback and documentation
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For documentation, providing feedback, issues and finding out how to contribute please refer to the [Home repo](https://github.com/nanoframework/Home).

‎System.Device.Pwm/PwmChannel.cs‎

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@@ -17,10 +17,10 @@ public sealed class PwmChannel : IDisposable
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[System.Diagnostics.DebuggerBrowsable(System.Diagnostics.DebuggerBrowsableState.Never)]
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private uint _dutyCycle;
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#pragma warning disable 0414
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#pragma warning disable 0414
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[System.Diagnostics.DebuggerBrowsable(System.Diagnostics.DebuggerBrowsableState.Never)]
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private PwmPulsePolarity _polarity;
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#pragma warning restore 0414
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#pragma warning restore 0414
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[System.Diagnostics.DebuggerBrowsable(System.Diagnostics.DebuggerBrowsableState.Never)]
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private int _pinNumber;
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}
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/// <summary>
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/// Creates a new instance of the <see cref="PwmChannel"/> running on the current platform. (Windows 10 IoT or Unix/Raspbian)
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/// Creates a new instance of the <see cref="PwmChannel"/> running on the current platform.
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/// </summary>
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/// <param name="chip">The PWM chip number.</param>
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/// <param name="channel">The PWM channel number.</param>
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/// <param name="chip">The PWM chip number, formally known as TIM channel.</param>
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/// <param name="channel">The PWM pin number or channel number depending on your platform.</param>
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/// <param name="frequency">The frequency in hertz.</param>
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/// <param name="dutyCyclePercentage">The duty cycle percentage represented as a value between 0.0 and 1.0.</param>
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/// <returns>A PWM channel</returns>
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}
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/// <summary>
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/// Creates a new instance of the <see cref="PwmChannel"/> running on the current platform. (Windows 10 IoT or Unix/Raspbian)
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/// Creates a PwmChannel from a pin number.
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/// </summary>
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/// <param name="chip">The PWM chip number.</param>
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/// <param name="channel">The PWM channel number.</param>
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/// <param name="pin">The pin number.</param>
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/// <param name="frequency">The frequency in hertz.</param>
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/// <param name="dutyCyclePercentage">The duty cycle percentage represented as a value between 0.0 and 1.0.</param>
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/// <returns>A PWM channel</returns>
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public static PwmChannel CreateFromPin(int pin, int frequency = 400, double dutyCyclePercentage = 0.5)
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{
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int channel = -1;
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int chip;
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// We do have a channels from 0 to 8
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for (chip = 0; chip < 8; chip++)
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{
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channel = GetChannel(pin, chip);
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if (channel != -1)
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{
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break;
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}
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}
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if (channel == -1)
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{
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return null;
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}
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return new PwmChannel(chip, channel, frequency, dutyCyclePercentage);
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}
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/// <summary>
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/// Creates a new instance of the <see cref="PwmChannel"/> running on the current platform.
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/// </summary>
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/// <param name="chip">The PWM chip number, formally known as TIM channel.</param>
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/// <param name="channel">The PWM pin number or channel number depending on your platform.</param>
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/// <param name="frequency">The frequency in hertz.</param>
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/// <param name="dutyCyclePercentage">The duty cycle percentage represented as a value between 0.0 and 1.0.</param>
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/// <returns>A PWM channel</returns>
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public PwmChannel(
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int chip,
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int chip,
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int channel,
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int frequency = 400,
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double dutyCyclePercentage = 0.5)
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}
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}
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// // TODO: override finalizer only if 'Dispose(bool disposing)' has code to free unmanaged resources
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// ~PwmChannel()
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// {
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// // Do not change this code. Put cleanup code in 'Dispose(bool disposing)' method
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// Dispose(disposing: false);
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// }
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/// <inheritdoc cref="IDisposable.Dispose"/>
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public void Dispose()
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{
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[MethodImpl(MethodImplOptions.InternalCall)]
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private extern void DisposeNative();
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[MethodImpl(MethodImplOptions.InternalCall)]
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private static extern int GetChannel(int pin, int timerId);
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#endregion
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}
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}

‎System.Device.Pwm/System.Device.Pwm.nfproj‎

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<Reference Include="mscorlib, Version=1.10.5.4, Culture=neutral, PublicKeyToken=c07d481e9758c731">
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<HintPath>..\packages\nanoFramework.CoreLibrary.1.10.5\lib\mscorlib.dll</HintPath>
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<Private>True</Private>
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<SpecificVersion>True</SpecificVersion>
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</Reference>
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</ItemGroup>
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<Import Project="$(NanoFrameworkProjectSystemPath)NFProjectSystem.CSharp.targets" Condition="Exists('$(NanoFrameworkProjectSystemPath)NFProjectSystem.CSharp.targets')" />

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