RaspberryIO/Unosquare.RaspberryIO/Native/WiringPi.SoftPwm.cs

using System;
using System.Runtime.InteropServices;

namespace Unosquare.RaspberryIO.Native {
  public partial class WiringPi {
    #region WiringPi - Soft PWM (https://github.com/WiringPi/WiringPi/blob/master/wiringPi/softPwm.h)

    /// <summary>
    /// This creates a software controlled PWM pin. You can use any GPIO pin and the pin numbering will be that of the wiringPiSetup()
    /// function you used. Use 100 for the pwmRange, then the value can be anything from 0 (off) to 100 (fully on) for the given pin.
    /// The return value is 0 for success. Anything else and you should check the global errno variable to see what went wrong.
    /// </summary>
    /// <param name="pin">The pin.</param>
    /// <param name="initialValue">The initial value.</param>
    /// <param name="pwmRange">The PWM range.</param>
    /// <returns>The result</returns>
    [DllImport(WiringPiLibrary, EntryPoint = "softPwmCreate", SetLastError = true)]
    public static extern Int32 SoftPwmCreate(Int32 pin, Int32 initialValue, Int32 pwmRange);

    /// <summary>
    /// This updates the PWM value on the given pin. The value is checked to be in-range and pins that haven’t previously
    /// been initialized via softPwmCreate will be silently ignored.
    /// </summary>
    /// <param name="pin">The pin.</param>
    /// <param name="value">The value.</param>
    [DllImport(WiringPiLibrary, EntryPoint = "softPwmWrite", SetLastError = true)]
    public static extern void SoftPwmWrite(Int32 pin, Int32 value);

    /// <summary>
    /// This function is undocumented
    /// </summary>
    /// <param name="pin">The pin.</param>
    [DllImport(WiringPiLibrary, EntryPoint = "softPwmStop", SetLastError = true)]
    public static extern void SoftPwmStop(Int32 pin);

    /// <summary>
    /// This creates a software controlled tone pin. You can use any GPIO pin and the pin numbering will be that of the wiringPiSetup() function you used.
    /// The return value is 0 for success. Anything else and you should check the global errno variable to see what went wrong.
    /// </summary>
    /// <param name="pin">The pin.</param>
    /// <returns>The result</returns>
    [DllImport(WiringPiLibrary, EntryPoint = "softToneCreate", SetLastError = true)]
    public static extern Int32 SoftToneCreate(Int32 pin);

    /// <summary>
    /// This function is undocumented
    /// </summary>
    /// <param name="pin">The pin.</param>
    [DllImport(WiringPiLibrary, EntryPoint = "softToneStop", SetLastError = true)]
    public static extern void SoftToneStop(Int32 pin);

    /// <summary>
    /// This updates the tone frequency value on the given pin. The tone will be played until you set the frequency to 0.
    /// </summary>
    /// <param name="pin">The pin.</param>
    /// <param name="freq">The freq.</param>
    [DllImport(WiringPiLibrary, EntryPoint = "softToneWrite", SetLastError = true)]
    public static extern void SoftToneWrite(Int32 pin, Int32 freq);

    #endregion

  }
}