using System;

public class Program

{

    public static void Main()

    {

        byte fixQuality = 0;

        float lat = 55.72186F;

        var blat = BitConverter.GetBytes(lat);

        //Console.WriteLine(blat.Length.ToString());

        //Console.WriteLine(BitConverter.ToString(blat));

        float lon = 12.55918F;

        var blon = BitConverter.GetBytes(lon);  

        //Console.WriteLine(blon.Length.ToString());

        //Console.WriteLine(BitConverter.ToString(blon));

        float alt = 6.3F;

        var balt = BitConverter.GetBytes(alt);      

        //Console.WriteLine(balt.Length.ToString());

        //Console.WriteLine(BitConverter.ToString(balt));

        short direction = 1;

        var bdir = BitConverter.GetBytes(direction);

        short hdop = 0;

        var bhdop = BitConverter.GetBytes(hdop);

        byte nsat = 1;

        byte lock_state = 2;

        var block = BitConverter.GetBytes(true);

        //Console.WriteLine(block.Length.ToString());

        //Console.WriteLine(BitConverter.ToString(block));

        byte dock_state = 2;

        var bdock = BitConverter.GetBytes(true);

        //Console.WriteLine(bdock.Length.ToString());

        //Console.WriteLine(BitConverter.ToString(bdock));

        int unixTimestamp = (Int32)(DateTime.UtcNow.Subtract(new DateTime(1970, 1, 1))).TotalSeconds;

        var bunixTs =  BitConverter.GetBytes(unixTimestamp);

        int sessionId = 3983026;

        var bSessionId = BitConverter.GetBytes(sessionId);

        byte charger_state = 2;

        var bcharge = BitConverter.GetBytes(true);

        //Console.WriteLine(bcharge.Length.ToString());

        //Console.WriteLine(BitConverter.ToString(bcharge));

        byte keystate = 0;

        var bks = BitConverter.GetBytes(keystate);

        //Console.WriteLine(bks.Length.ToString());

        //Console.WriteLine(BitConverter.ToString(bks));

        var bchargekeystate = new HalvedByte(keystate,charger_state);

        var b42v = Convert.ToByte(true);

        //Console.WriteLine(b42v.Length.ToString());

        //Console.WriteLine(BitConverter.ToString(b42v));

        var bswitch = Convert.ToByte(true);

        //Console.WriteLine(bswitch.Length.ToString());

        //Console.WriteLine(BitConverter.ToString(bswitch));

        var v42_battery = new HalvedByte(bswitch, b42v);    

        string dock_uid = "12ABC34";

        var bdockuid = System.Text.Encoding.ASCII.GetBytes(dock_uid);

        //Console.WriteLine(bdockuid.Length.ToString());

        //Console.WriteLine(BitConverter.ToString(bdockuid));

        byte[] request = new byte[37] { 

            fixQuality,

            blat[0],blat[1],blat[2],blat[3], 

            blon[0],blon[1],blon[2],blon[3],

            balt[0],balt[1],balt[2],balt[3],

            bdir[0],bdir[1],

            bhdop[0], bhdop[1],

            nsat,

            bunixTs[0], bunixTs[1], bunixTs[2], bunixTs[3],

            bSessionId[0], bSessionId[1], bSessionId[2], bSessionId[3],

            lock_state, 

            dock_state, 

            bchargekeystate.Full, 

            v42_battery.Full,

            bdockuid[0],bdockuid[1],bdockuid[2],bdockuid[3],bdockuid[4],bdockuid[5],bdockuid[6]};

        var bstring = Convert.ToBase64String(request);

        Console.WriteLine(bstring);

    }

​

​

public struct HalvedByte

    {

        public byte Full { get; set; }

​

        public byte Low

        {

            get { return (byte)(Full & 15); }

​

            set

            {

                if (value >= 16)

                {

                    throw new ArithmeticException("Value must be between 0 and 16.");

                }

​

                Full = (byte)((High << 4) | (value & 15));

            }

        }

​

        public byte High

        {

            get { return (byte)(Full >> 4); }

​

            set

            {

                if (value >= 16)

                {

                    throw new ArithmeticException("Value must be between 0 and 16.");

                }

​

                Full = (byte)((value << 4) | Low);

            }

        }

​

        public HalvedByte(byte full) : this()

        {

            Full = full;

        }

​

        public HalvedByte(byte low, byte high) : this()

        {

            if (low >= 16 || high >= 16)

            {

                throw new ArithmeticException("Values must be between 0 and 16.");

            }

​

            Full = (byte)((high << 4) | low);

        }

    }

}