Rx.cs

using System;
using System.Reactive.Linq;
using System.Reactive.Subjects;
using System.Threading.Tasks;
using Reactive.Bindings;

namespace RxLab
{
    class Program
    {
        static async Task Main(string[] args)
        {
            var sensor = new ChatteringSensor();
            sensor.Value.Throttle(TimeSpan.FromMilliseconds(200))
                .Subscribe(x => Console.WriteLine($"Throttle: {x}"));

            Console.WriteLine("---- Start ----");
            await sensor.OnAsync();
            await Task.Delay(1000);
            await sensor.OnAsync();
            await Task.Delay(1000);
            await sensor.OffAsync();
            await Task.Delay(1000);
            await sensor.OffAsync();
            await Task.Delay(1000);
        }
    }

    class ChatteringSensor
    {
        private Random Random { get; } = new Random();
        private Subject<bool> Source { get; } = new Subject<bool>();
        public ReadOnlyReactiveProperty<bool> Value { get; }

        public ChatteringSensor()
        {
            Value = Source.ToReadOnlyReactiveProperty(mode: ReactivePropertyMode.RaiseLatestValueOnSubscribe);
        }

        public Task OnAsync()
        {
            return Task.Run(async () =>
            {
                var count = Random.Next(10) + 5;
                for (var i = 0; i < count; i++)
                {
                    Source.OnNext(Random.Next() % 2 == 0);
                    await Task.Delay(Random.Next(100));
                }

                Source.OnNext(true);
            });
        }

        public Task OffAsync()
        {
            return Task.Run(async () =>
            {
                var count = Random.Next(10) + 5;
                for (var i = 0; i < count; i++)
                {
                    Source.OnNext(Random.Next() % 2 == 0);
                    await Task.Delay(Random.Next(100));
                }

                Source.OnNext(false);
            });
        }
    }
}