Thanks Eric,
I got it working and now feel stupid.
What I was doing was creating an array of 8 Bytes, putting the Date and Time info in their places then sending that to the CRC function. After getting a ushort (16-bit number) from the CRC function I took the 2 bytes and put them into my "Timearray" at elements 6 and 7 (0 indexed array BTW).
So what was happening is the CRC function would calculate a CRC for all 8 bytes in the array including the 2 that the CRC was going to go into.
What I'm doing now is creating an array of 6 Bytes, putting the Date and Time values in their places, then sending that to the CRC function. After getting the 16-bit CRC from the CRC function I'm resizing the Byte array into 8 elements and putting the 2 Bytes of the CRC into elements 6 and 7.
Best to show you with Code, so here's what I was doing:
This is wrongpublic static Boolean SetTime(DateTime time)
{
Byte[] TimeArray = new Byte[8]; //this should be created with 6 not 8 elements
TimeArray[0] = (Byte)time.Second;
TimeArray[1] = (Byte)time.Minute;
TimeArray[2] = (Byte)time.TimeOfDay.Hours;
TimeArray[3] = (Byte)time.Day;
TimeArray[4] = (Byte)time.Month;
TimeArray[5] = (Byte)(time.Year - 2000);
Byte[] tempCRC = BitConverter.GetBytes(CRC_Check(ref TimeArray));
// need to resize the Timearray here
TimeArray[6] = tempCRC[1];
TimeArray[7] = tempCRC[0];
Console.WriteLine("Sending 'SetTime' command...");
Byte[][] ComRply = sendCommand(Encoding.ASCII.GetBytes("SetTime\n"), commStream);
if (ComRply[0][0] == (Byte)6)
{
Console.WriteLine("Sending Time...");
ComRply = sendCommand(TimeArray, commStream);
if (ComRply[0][0] == (Byte)6)
{
return true;
}
}
return false;
}
here's the
Working code:
public static Boolean SetTime(DateTime time)
{
Byte[] TimeArray = new Byte[6]; // this is how it should be created
TimeArray[0] = (Byte)time.Second;
TimeArray[1] = (Byte)time.Minute;
TimeArray[2] = (Byte)time.TimeOfDay.Hours;
TimeArray[3] = (Byte)time.Day;
TimeArray[4] = (Byte)time.Month;
TimeArray[5] = (Byte)(time.Year - 2000);
Byte[] tempCRC = BitConverter.GetBytes(CRC_Check(ref TimeArray));
Array.Resize(ref TimeArray, 8); // this is added
TimeArray[6] = tempCRC[1];
TimeArray[7] = tempCRC[0];
Console.WriteLine("Sending 'SetTime' command...");
Byte[][] ComRply = sendCommand(Encoding.ASCII.GetBytes("SetTime\n"), commStream);
if (ComRply[0][0] == (Byte)6)
{
Console.WriteLine("Sending Time...");
ComRply = sendCommand(TimeArray, commStream);
if (ComRply[0][0] == (Byte)6)
{
return true;
}
}
return false;
}
and Here's the code that does the actual CRC part. Copied from the Davis documentation.
private static ushort CRC_Check(ref byte[] Data_Array)
{
ushort crc = 0;
foreach (byte Tempbyte in Data_Array)
{
crc = Convert.ToUInt16(CRC_Table[(crc >> 8) ^ Tempbyte] ^ ((crc & 0xff) << 8));
}
return crc;
}
private static readonly ushort[] CRC_Table = {
0x0,0x1021, 0x2042, 0x3063, 0x4084, 0x50a5, 0x60c6, 0x70e7, 0x8108, 0x9129, 0xa14a, 0xb16b, 0xc18c, 0xd1ad, 0xe1ce, 0xf1ef, 0x1231, 0x210, 0x3273, 0x2252, 0x52b5, 0x4294,
0x72f7, 0x62d6, 0x9339, 0x8318, 0xb37b, 0xa35a, 0xd3bd, 0xc39c, 0xf3ff, 0xe3de, 0x2462, 0x3443, 0x420, 0x1401, 0x64e6, 0x74c7, 0x44a4, 0x5485, 0xa56a, 0xb54b, 0x8528,
0x9509, 0xe5ee, 0xf5cf, 0xc5ac, 0xd58d, 0x3653, 0x2672, 0x1611, 0x630, 0x76d7, 0x66f6, 0x5695, 0x46b4, 0xb75b, 0xa77a, 0x9719, 0x8738, 0xf7df, 0xe7fe, 0xd79d, 0xc7bc,
0x48c4, 0x58e5, 0x6886, 0x78a7, 0x840, 0x1861, 0x2802, 0x3823, 0xc9cc, 0xd9ed, 0xe98e, 0xf9af, 0x8948, 0x9969, 0xa90a, 0xb92b, 0x5af5, 0x4ad4, 0x7ab7, 0x6a96, 0x1a71,
0xa50, 0x3a33, 0x2a12, 0xdbfd, 0xcbdc, 0xfbbf, 0xeb9e, 0x9b79, 0x8b58, 0xbb3b, 0xab1a, 0x6ca6, 0x7c87, 0x4ce4, 0x5cc5, 0x2c22, 0x3c03, 0xc60, 0x1c41, 0xedae, 0xfd8f,
0xcdec, 0xddcd, 0xad2a, 0xbd0b, 0x8d68, 0x9d49, 0x7e97, 0x6eb6, 0x5ed5, 0x4ef4, 0x3e13, 0x2e32, 0x1e51, 0xe70, 0xff9f, 0xefbe, 0xdfdd, 0xcffc, 0xbf1b, 0xaf3a, 0x9f59,
0x8f78, 0x9188, 0x81a9, 0xb1ca, 0xa1eb, 0xd10c, 0xc12d, 0xf14e, 0xe16f, 0x1080, 0xa1, 0x30c2, 0x20e3, 0x5004, 0x4025, 0x7046, 0x6067, 0x83b9, 0x9398, 0xa3fb, 0xb3da,
0xc33d, 0xd31c, 0xe37f, 0xf35e, 0x2b1, 0x1290, 0x22f3, 0x32d2, 0x4235, 0x5214, 0x6277, 0x7256, 0xb5ea, 0xa5cb, 0x95a8, 0x8589, 0xf56e, 0xe54f, 0xd52c, 0xc50d, 0x34e2,
0x24c3, 0x14a0, 0x481, 0x7466, 0x6447, 0x5424, 0x4405, 0xa7db, 0xb7fa, 0x8799, 0x97b8, 0xe75f, 0xf77e, 0xc71d, 0xd73c, 0x26d3, 0x36f2, 0x691, 0x16b0, 0x6657, 0x7676,
0x4615, 0x5634, 0xd94c, 0xc96d, 0xf90e, 0xe92f, 0x99c8, 0x89e9, 0xb98a, 0xa9ab, 0x5844, 0x4865, 0x7806, 0x6827, 0x18c0, 0x8e1, 0x3882, 0x28a3, 0xcb7d, 0xdb5c, 0xeb3f,
0xfb1e, 0x8bf9, 0x9bd8, 0xabbb, 0xbb9a, 0x4a75, 0x5a54, 0x6a37, 0x7a16, 0xaf1, 0x1ad0, 0x2ab3, 0x3a92, 0xfd2e, 0xed0f, 0xdd6c, 0xcd4d, 0xbdaa, 0xad8b, 0x9de8, 0x8dc9,
0x7c26, 0x6c07, 0x5c64, 0x4c45, 0x3ca2, 0x2c83, 0x1ce0, 0xcc1, 0xef1f, 0xff3e, 0xcf5d, 0xdf7c, 0xaf9b, 0xbfba, 0x8fd9, 0x9ff8, 0x6e17, 0x7e36, 0x4e55, 0x5e74, 0x2e93,
0x3eb2, 0xed1, 0x1ef0
};
The one thing that You don't see in the code above is the "sendCommand" function. It takes a Byte Array and an IO.Stream as parameters, sends the byte array over the IO.Stream and returns whatever (if anything) the Console replies with. Now the Byte array it returns is a multi dimensional "jagged" array created by splitting the Consoles reply by the "\n\r" chars. But thats my own choice of implementation.