using System;

using System.Collections.Generic;

using Newtonsoft.Json;

​

public class Program

{

    public static void Main()

    {

        List<byte> uartBytes = new List<byte>()

        {

            0xF1,

            0x94

        };

        Console.WriteLine(CalculateChecksum(uartBytes, false).ToString());

    }

    public static byte CalculateChecksum(List<byte> data, bool isMaster)

        {

            /* Seed value from Interface specification - Figure A.4 */

            byte seedValue = 0x52;

            byte crc = 0;

            byte compressedCrc = 0;

​

            /* XOR the message with the seed value */

            crc = seedValue;

            if (isMaster)

            {

                for (int i = 0; i < data.Count; i++)

                {

                    if (i == 1)

                    {

                        crc ^= (byte)(data[i] & 0xC0);

                    }

                    else

                    {

                        crc ^= data[i];

                    }

                }

            }

            else

            {

                for (int i = 0; i < data.Count; i++)

                {

                    if (i == data.Count - 1)

                    {

                        crc ^= (byte)(data[i] & 0xC0);

                    }

                    else

                    {

                        crc ^= data[i];

                    }

                }

            }

​

            byte bit1 = (byte)(crc & 1);

            byte bit2 = (byte)((crc & 2) >> 1);

            byte bit3 = (byte)((crc & 4) >> 2);

            byte bit4 = (byte)((crc & 8) >> 3);

            byte bit5 = (byte)((crc & 16) >> 4);

            byte bit6 = (byte)((crc & 32) >> 5);

            byte bit7 = (byte)((crc & 64) >> 6);

            byte bit8 = (byte)((crc & 128) >> 7);

​

            /* Compress the checksum into 6 bit value */

            //BIT 1 = BIT 1 xor BIT 2

            compressedCrc |= (byte)(bit1 ^ bit2);

            //BIT 2 = BIT 3 xor BIT 4

            compressedCrc |= (byte)((bit3 ^ bit4) << 1);

            //BIT 3 = BIT 5 xor BIT 6

            compressedCrc |= (byte)((bit5 ^ bit6) << 2);

            //BIT 4 = BIT 7 xor BIT 8

            compressedCrc |= (byte)((bit7 ^ bit8) << 3);

            //BIT 5 = 1, 3, 5, 7 BIT xored

            compressedCrc |= (byte)((bit1 ^ bit3 ^ bit5 ^ bit7) << 4);

            //BIT 6 = 2, 4, 6, 8 BIT xored

            compressedCrc |= (byte)((bit2 ^ bit4 ^ bit6 ^ bit8) << 5);

​

            return compressedCrc;

        }

}

​