private void Encode(uint crcInitialValue = 0x0)
{
var bytes = new List <byte>();
var frameControlByte0 = (byte)Type;
if (FramePending)
{
frameControlByte0 |= (0x1 << 4);
}
bytes.Add(frameControlByte0);
bytes.Add(0); // frameControlByte1
bytes.Add(DataSequenceNumber);
if (AddressInformation != null && AddressInformation.Bytes.Count > 0)
{
bytes.AddRange(AddressInformation.Bytes);
}
if (Payload != null && Payload.Count > 0)
{
bytes.AddRange(Payload);
}
var crcLength = CRCPolynomial.GetLength();
var crc = CalculateCRC(bytes, crcInitialValue, CRCPolynomial);
switch (crcLength)
{
case 2:
bytes.Add(crc[0]);
bytes.Add(crc[1]);
break;
case 4:
bytes.Add(crc[0]);
bytes.Add(crc[1]);
bytes.Add(crc[2]);
bytes.Add(crc[3]);
break;
default:
Logger.Log(LogLevel.Error, "Cannot generate CRC of invalid length {0}, the packet will not contain CRC data", crcLength);
break;
}
Bytes = bytes.ToArray();
}
public bool CheckCRC(uint crcInitialValue = 0x0)
{
var crcLength = CRCPolynomial.GetLength();
var crc = CalculateCRC(Bytes.Take(Bytes.Length - crcLength), crcInitialValue, CRCPolynomial);
// Byte little endian order
switch (crcLength)
{
case 2:
return(Bytes[Bytes.Length - 2] == crc[0] && Bytes[Bytes.Length - 1] == crc[1]);
case 4:
return(Bytes[Bytes.Length - 4] == crc[0] && Bytes[Bytes.Length - 3] == crc[1] && Bytes[Bytes.Length - 2] == crc[2] && Bytes[Bytes.Length - 1] == crc[3]);
default:
Logger.Log(LogLevel.Error, "Cannot check CRC of invalid length {0}", crcLength);
return(false);
}
}