static void TestRotate()
        {
            Console.WriteLine("Testing a servo motor controlled by a rotary encoder");
            var       angle = 0;
            const int step  = 10;

            using (var left = Pi.Gpio.Pin(leftPin, PinKind.InputPullUp))
                using (var right = Pi.Gpio.Pin(rightPin, PinKind.InputPullUp))
                    using (var servo = new ServoMotor(maxAngle))
                    {
                        servo.PulseWidths(0.5, 2.5);
                        servo.Start();
                        // Connect rotate and click events
                        left.OnRisingEdge += Rotate;
                        Console.WriteLine("Click the button to stop this test");
                        Pi.Gpio.Pin(buttonPin, PinKind.InputPullUp).WaitForEdge(PinEdge.Rising);
                        left.OnRisingEdge -= Rotate;
                        servo.Angle        = 0;
                        Pi.Wait(2000);
                        servo.Stop();

                        // Called on the falling edge of the left pin
                        void Rotate(object sender, PinEventHandlerArgs args)
                        {
                            if (args.Bounced)
                            {
                                return;
                            }
                            var a = angle;

                            a += left.Value == right.Value ? -step : step;
                            if (a < 0)
                            {
                                a = 0;
                            }
                            if (a > maxAngle)
                            {
                                a = maxAngle;
                            }
                            if (a != angle)
                            {
                                Console.WriteLine("servo angle at {0}°", servo.Angle = angle = a);
                            }
                        }
                    }
        }
        static void TestSweep()
        {
            Console.WriteLine("Testing a servo motor in a sweeping motion");
            var angle = 0d;
            var step  = 0.1d;
            var done  = false;

            using (var left = Pi.Gpio.Pin(leftPin, PinKind.InputPullUp))
                using (var right = Pi.Gpio.Pin(rightPin, PinKind.InputPullUp))
                    using (var servo = new ServoMotor(maxAngle))
                    {
                        servo.PulseWidths(0.5, 2.5);
                        servo.Start();
                        var timer = PreciseTimer.Every(1, () =>
                        {
                            if (done)
                            {
                                return(false);
                            }
                            angle += step;
                            var a  = angle % (maxAngle * 2);
                            if (a > maxAngle)
                            {
                                a = (maxAngle * 2) - a;
                            }
                            servo.Angle = a;
                            return(true);
                        });
                        Console.WriteLine("Click the button to stop this test");
                        // Connect rotate and click events
                        left.OnRisingEdge += Rotate;
                        Pi.Gpio.Pin(buttonPin, PinKind.InputPullUp).WaitForEdge(PinEdge.Rising);
                        left.OnRisingEdge -= Rotate;
                        done = true;
                        timer.Wait();
                        servo.Angle = 0;
                        Pi.Wait(2000);

                        // Called on the falling edge of the left pin
                        void Rotate(object sender, PinEventHandlerArgs args)
                        {
                            if (args.Bounced)
                            {
                                return;
                            }
                            var s = step;

                            if (left.Value == right.Value)
                            {
                                s += 0.1;
                            }
                            else
                            {
                                s -= 0.1;
                            }
                            if (s < 0)
                            {
                                s = 0;
                            }
                            step = s;
                            Console.WriteLine("servo step {0:0.0}°", step);
                        }
                    }
        }