Control LifeSpan treadmill from C# (treadmill drops connection if not kept alive)

LifeSpan.cs

// License: MIT

using System;
using System.Collections.Concurrent;
using System.IO;
using System.Linq;
using System.Threading.Tasks;

public class LifeSpanTreadmill: IDisposable
{
    readonly Stream toDevice, fromDevice;
    readonly byte[] responseBuffer = new byte[8];
    volatile bool stop;
    readonly Task keepAliveLoop;
    readonly ConcurrentQueue<Action> requests = new ConcurrentQueue<Action>();

    public LifeSpanTreadmill(Stream toDevice, Stream fromDevice) {
        this.toDevice = toDevice ?? throw new ArgumentNullException(nameof(toDevice));
        this.fromDevice = fromDevice ?? throw new ArgumentNullException(nameof(fromDevice));
        this.keepAliveLoop = Task.Run((Action)this.KeepAliveLoop);
    }

    public LifeSpanTreadmill(Stream deviceStream) {
        this.toDevice = this.fromDevice = deviceStream ?? throw new ArgumentNullException(nameof(deviceStream));
        this.keepAliveLoop = Task.Run((Action)this.KeepAliveLoop);
    }

    public void Start() => this.SendCommand(Command.Start);
    public void Stop() => this.SendCommand(Command.Stop);

    void KeepAliveLoop() {
        while (!this.stop) {
            while (this.requests.TryDequeue(out Action action))
                action();

            this.SendInitSequence();
            long speed = this.SendPacket((uint)Command.GetSpeed);
        }
    }

    void SendInitSequence() {
        long[] resposes = new uint[] {
            0x20000000,
            0xC2000000,
            0xE9FF0000,
            0xE400F400,
        }.Select(this.SendPacket).ToArray();
    }

    long SendCommand(Command command) => this.SendCommandAsync(command).Result;

    Task<long> SendCommandAsync(Command command) {
        var result = new TaskCompletionSource<long>();
        this.requests.Enqueue(() => {
            try {
                this.SendInitSequence();
                long response = this.SendPacket((uint)command);
                result.TrySetResult(response);
            } catch (Exception e) {
                result.TrySetException(e);
            }
        });
        return result.Task;
    }

    long SendPacket(uint command) {
        byte[] bytes = BitConverter.GetBytes(command);
        if (BitConverter.IsLittleEndian)
            Array.Reverse(bytes);
        this.toDevice.Write(bytes, 0, 4);
        this.toDevice.WriteByte(0);
        this.toDevice.Flush();
        int read = this.fromDevice.Read(this.responseBuffer, 0, 6);
        if (read < 6)
            throw new NotSupportedException();
        long result = BitConverter.ToInt64(this.responseBuffer, 0);
        return result;
    }

    static decimal ToDecimal(long response) => response & 0xFF;

    public void Dispose() {
        this.stop = true;
        this.keepAliveLoop.Wait();
    }

    enum Command: uint
    {
        Start = 0xE1000000,
        Stop = 0xE0000000,
        GetSteps = 0xA1880000,
        GetCalories = 0xA1870000,
        GetDistance = 0xA1850000,
        GetTime = 0xA1890000,
        GetSpeed = 0xA1820000,
    }
}

@lukescott Will a RS-232 Tester work?

https://www.amazon.com/CableMax-RS-232-link-Tester-Female/dp/B004OT995U

@icnocop sadly it’s non standard. Even if it was RS-232, the pins are not where they should be. I don’t have the tools needed to decode the signal. Sticking the wrong voltage on the wrong pins could cause damage. I was lucky to not cause any harm with the probing I did do. - I’m updating my retro console to the Omni hub and giving Bluetooth a shot.