MeadowApp.cs

using Meadow;
using Meadow.Devices;
using Meadow.Hardware;
using Meadow.Units;
using System;
using System.Threading.Tasks;

namespace AnalogInputPort;

public class MeadowApp : App<F7FeatherV2>
{
    IAnalogInputPort analogIn;

    public override Task Initialize()
    {
        Resolver.Log.Info("Initializing hardware...");

        analogIn = Device.CreateAnalogInputPort(Device.Pins.A00);

        analogIn.Updated += (s, result) =>
        {
            Resolver.Log.Info($"Analog event, new voltage: {result.New.Volts:N2}V, old: {result.Old?.Volts:N2}V");
        };

        var observer = IAnalogInputPort.CreateObserver(
            handler: result =>
            {
                Resolver.Log.Info($"Analog observer triggered; new: {result.New.Volts:n2}V, old: {result.Old?.Volts:n2}V");
            },
            // filter is optional. in this case, we're only notifying if the
            // voltage changes by at least `0.1V`.
            filter: result =>
            {
                if (result.Old is { } oldValue)
                {
                    return (result.New - oldValue).Abs().Volts > 0.1;
                }
                else { return false; }
            }
        );
        analogIn.Subscribe(observer);

        Resolver.Log.Info("Hardware initialized.");

        return base.Initialize();
    }

    public override async Task Run()
    {
        Voltage voltageReading = await analogIn.Read();
        Resolver.Log.Info($"Voltages: {voltageReading.Volts:N3}");

        analogIn.StartUpdating(TimeSpan.FromSeconds(1));
    }
}