implement additional code review feedback

tools/DevicesApiTester/Commands/Pwm/PwmCommand.cs

@@ -13,14 +13,14 @@ namespace DeviceApiTester.Commands.Pwm
         [Option('d', "driver", HelpText = "The PwmDriver to use: { Windows | Unix }", Required = false, Default = PwmDriverType.Windows)]
         public PwmDriverType Driver { get; set; }
 
-        [Option("pwm-chip", HelpText = "The PWM chip (controller) to use", Required = false, Default = 0)]
+        [Option("chip", HelpText = "The PWM chip (controller) to use", Required = false, Default = 0)]
         public int PwmChip { get; set; }
 
-        [Option("pwm-channel", HelpText = "The PWM channel (pin) to use", Required = false, Default = 0)]
+        [Option("channel", HelpText = "The PWM channel (pin) to use", Required = false, Default = 0)]
         public int PwmChannel { get; set; }
 
-        [Option('c', "dutycycle", HelpText = "The duty cycle for PWM output from 1-100", Required = false, Default = 50)]
-        public int DutyCycle { get; set; }
+        [Option('c', "dutycycle", HelpText = "The duty cycle for PWM output from 1.0-100.0", Required = false, Default = 50.0)]
+        public double DutyCycle { get; set; }
 
         [Option('f', "frequency", HelpText = "The frequency in hertz", Required = false, Default = 400.0)]
         public double Frequency { get; set; }
@@ -29,7 +29,9 @@ namespace DeviceApiTester.Commands.Pwm
         {
             PwmDriver pwmDriver = DriverFactory.CreateFromEnum<PwmDriver, PwmDriverType>(this.Driver);
 
-            return new PwmController(pwmDriver);
+            return pwmDriver != null
+                ? new PwmController(pwmDriver)
+                : new PwmController();
         }
     }
 }
\ No newline at end of file

tools/DevicesApiTester/Commands/Pwm/PwmDriverType.cs

@@ -9,6 +9,9 @@ namespace DeviceApiTester.Commands.Pwm
 {
     public enum PwmDriverType
     {
+        [ImplementationType(null)]
+        Default,
+
         [ImplementationType(typeof(Windows10PwmDriver))]
         Windows,
 

tools/DevicesApiTester/Commands/Pwm/PwmPinOutput.cs

@@ -24,11 +24,11 @@ namespace DeviceApiTester.Commands.Pwm
         {
             using (var pwm = CreatePwmController())
             {
-                Console.WriteLine("Enabling PWM output with chip {0} / channel {1}, {2}% duty cycle @ {3}hz for {4} seconds ", PwmChip, PwmChip, DutyCycle, Frequency, Seconds);
+                Console.WriteLine($"Enabling PWM output with chip {PwmChip} / channel {PwmChannel}, {DutyCycle}% duty cycle @ {Frequency}hz for {Seconds} seconds ");
 
                 pwm.OpenChannel(PwmChip, PwmChannel);
                 pwm.StartWriting(PwmChip, PwmChannel, Frequency, DutyCycle);
-                await Task.Delay(Seconds * 1000);
+                await Task.Delay(TimeSpan.FromSeconds(Seconds));
                 pwm.StopWriting(PwmChip, PwmChannel);
             }