I’m very happy, that RTTY trasmission works fine also with C# code, no need for RLP. I needed some trick to fasten the code.
enum CURRENT_MODE
{
NONE,
LETTERS,
FIGURES
}
public class Rtty
{
// constant define
const int ARRAY_LEN = 32;
const int LETTERS_SHIFT = 31;
const int FIGURES_SHIFT = 27;
const int LINEFEED = 2;
const int CARRRTN = 8;
const int DDS_REF = 180000000; // 30 MHZ osc x 6 PLL
const int RTTY_SHIFT = 170;
const string letters_arr = "§E\nA SIU\rDRJNFCKTZLWHYPQOBG MXV ";
const string figures_arr = "§3\n- \a87\r$4',!:(5\")2#6019?&.; ";
SPI _dds;
//public vars
int _rtty_freq;
int _rtty_offs;
ulong _frequency; // actual freq in HZ
byte _phase;
public Rtty(ulong frequency, SPI dds, byte phase)
{
_frequency = frequency;
_dds = dds;
_phase = phase;
}
public ulong ChangeFrequency(ulong new_freq, byte phase)
{
ulong old_freq = _frequency;
_frequency = new_freq;
_phase = phase;
SetDDSFrequency(_frequency);
return old_freq;
}
private void SetDDSFrequency(ulong freq)
{
byte[] data = new byte[5];
ulong tuning_word = (freq * (ulong)System.Math.Pow(2D, 32D)) / DDS_REF;
data[3] = Reverse( (byte)((tuning_word >> 24) & 0xFF));
data[2] = Reverse( (byte)((tuning_word >> 16) & 0xFF));
data[1] = Reverse( (byte)((tuning_word >> 8) & 0xFF));
data[0] = Reverse( (byte) (tuning_word & 0xFF));
data[4] = 0x80; // 6xref enabled
_dds.Write(data);
}
byte Reverse(byte x)
{
return BitReverseTable.BitReverseTable256[x];
}
bool IsLowerCase(char ch)
{
return ((ch) >= 'a' && (ch) <= 'z');
}
bool IsUpperCase(char ch)
{
return ((ch) >= 'A' && (ch) <= 'Z');
}
public void RttyTxString(string str)
{
CURRENT_MODE current_mode = CURRENT_MODE.NONE;
char c;
byte b;
int cc = 0;
for( int slen = 0; slen < str.Length; slen++)
{
c = str[cc];
/* some characters are available in both sets */
if (c == '\n')
{
RttyTxByte(LINEFEED);
}
else if (c == '\r')
{
RttyTxByte(CARRRTN);
}
else if (IsLowerCase(str[cc]) || IsUpperCase(str[cc]))
{
if (IsLowerCase(str[cc]))
{
c -= (char)32;
}
if (current_mode != CURRENT_MODE.LETTERS)
{
RttyTxByte(LETTERS_SHIFT);
current_mode = CURRENT_MODE.LETTERS;
}
RttyTxByte(char_to_baudot(c, letters_arr));
}
else
{
b = char_to_baudot(c, figures_arr);
if (b != 0 && current_mode != CURRENT_MODE.FIGURES)
{
RttyTxByte(FIGURES_SHIFT);
current_mode = CURRENT_MODE.FIGURES;
}
RttyTxByte(b);
}
cc++;
}
}
public void RttyTxByte(byte b)
{
byte i;
RttyTxBit(0);
/* TODO: I don't know if baudot is MSB first or LSB first */
//for (i = 4; i >= 0; i--)
for (i = 0; i < 5; i++)
{
if ((b & (1 << i)) != 0 )
RttyTxBit(1);
else
RttyTxBit(0);
}
RttyTxBit(1);
}
// Transmit a bit as a mark or space
public void RttyTxBit (int bit)
{
if (bit == 1)
{
// High - mark
SetDDSFrequency(_frequency + RTTY_SHIFT);
}
else
{
// Low - space
SetDDSFrequency(_frequency);
}
// Delay appropriately - tuned to 45.45 baud.
Thread.Sleep(20); //sets the baud rate
}
byte char_to_baudot(char c, string array)
{
byte i;
for (i = 0; i < array.Length; i++)
{
if (array[i] == c)
return i;
}
return 0;
}
}
public static class BitReverseTable
{
public static byte[] BitReverseTable256 = new byte[]
{
0x00, 0x80, 0x40, 0xC0, 0x20, 0xA0, 0x60, 0xE0, 0x10, 0x90, 0x50, 0xD0, 0x30, 0xB0, 0x70, 0xF0,
0x08, 0x88, 0x48, 0xC8, 0x28, 0xA8, 0x68, 0xE8, 0x18, 0x98, 0x58, 0xD8, 0x38, 0xB8, 0x78, 0xF8,
0x04, 0x84, 0x44, 0xC4, 0x24, 0xA4, 0x64, 0xE4, 0x14, 0x94, 0x54, 0xD4, 0x34, 0xB4, 0x74, 0xF4,
0x0C, 0x8C, 0x4C, 0xCC, 0x2C, 0xAC, 0x6C, 0xEC, 0x1C, 0x9C, 0x5C, 0xDC, 0x3C, 0xBC, 0x7C, 0xFC,
0x02, 0x82, 0x42, 0xC2, 0x22, 0xA2, 0x62, 0xE2, 0x12, 0x92, 0x52, 0xD2, 0x32, 0xB2, 0x72, 0xF2,
0x0A, 0x8A, 0x4A, 0xCA, 0x2A, 0xAA, 0x6A, 0xEA, 0x1A, 0x9A, 0x5A, 0xDA, 0x3A, 0xBA, 0x7A, 0xFA,
0x06, 0x86, 0x46, 0xC6, 0x26, 0xA6, 0x66, 0xE6, 0x16, 0x96, 0x56, 0xD6, 0x36, 0xB6, 0x76, 0xF6,
0x0E, 0x8E, 0x4E, 0xCE, 0x2E, 0xAE, 0x6E, 0xEE, 0x1E, 0x9E, 0x5E, 0xDE, 0x3E, 0xBE, 0x7E, 0xFE,
0x01, 0x81, 0x41, 0xC1, 0x21, 0xA1, 0x61, 0xE1, 0x11, 0x91, 0x51, 0xD1, 0x31, 0xB1, 0x71, 0xF1,
0x09, 0x89, 0x49, 0xC9, 0x29, 0xA9, 0x69, 0xE9, 0x19, 0x99, 0x59, 0xD9, 0x39, 0xB9, 0x79, 0xF9,
0x05, 0x85, 0x45, 0xC5, 0x25, 0xA5, 0x65, 0xE5, 0x15, 0x95, 0x55, 0xD5, 0x35, 0xB5, 0x75, 0xF5,
0x0D, 0x8D, 0x4D, 0xCD, 0x2D, 0xAD, 0x6D, 0xED, 0x1D, 0x9D, 0x5D, 0xDD, 0x3D, 0xBD, 0x7D, 0xFD,
0x03, 0x83, 0x43, 0xC3, 0x23, 0xA3, 0x63, 0xE3, 0x13, 0x93, 0x53, 0xD3, 0x33, 0xB3, 0x73, 0xF3,
0x0B, 0x8B, 0x4B, 0xCB, 0x2B, 0xAB, 0x6B, 0xEB, 0x1B, 0x9B, 0x5B, 0xDB, 0x3B, 0xBB, 0x7B, 0xFB,
0x07, 0x87, 0x47, 0xC7, 0x27, 0xA7, 0x67, 0xE7, 0x17, 0x97, 0x57, 0xD7, 0x37, 0xB7, 0x77, 0xF7,
0x0F, 0x8F, 0x4F, 0xCF, 0x2F, 0xAF, 0x6F, 0xEF, 0x1F, 0x9F, 0x5F, 0xDF, 0x3F, 0xBF, 0x7F, 0xFF
};
}
Very exciting … board is working nice, but RF amplificator is too noisy damned … need some more work about that.
