Initial addition of JT4 to library

Author: NT7S

JTEncode.cpp

@@ -47,7 +47,6 @@ JTEncode::JTEncode(void)
  *  Ensure that you pass a uint8_t array of size JT65_SYMBOL_COUNT to the method.
  *
  */
-
 void JTEncode::jt65_encode(char * message, uint8_t * symbols)
 {
   // Ensure that the message text conforms to standards
@@ -88,7 +87,6 @@ void JTEncode::jt65_encode(char * message, uint8_t * symbols)
  *  Ensure that you pass a uint8_t array of size JT9_SYMBOL_COUNT to the method.
  *
  */
-
 void JTEncode::jt9_encode(char * message, uint8_t * symbols)
 {
   // Ensure that the message text conforms to standards
@@ -123,6 +121,44 @@ void JTEncode::jt9_encode(char * message, uint8_t * symbols)
   jt9_merge_sync_vector(a, symbols);
 }
 
+/*
+ * jt9_encode(char * message, uint8_t * symbols)
+ *
+ * Takes an arbitrary message of up to 13 allowable characters and returns
+ * a channel symbol table.
+ *
+ * message - Plaintext Type 6 message.
+ * symbols - Array of channel symbols to transmit retunred by the method.
+ *  Ensure that you pass a uint8_t array of size JT9_SYMBOL_COUNT to the method.
+ *
+ */
+void JTEncode::jt4_encode(char * message, uint8_t * symbols)
+{
+  // Ensure that the message text conforms to standards
+  // --------------------------------------------------
+  jt_message_prep(message);
+
+  // Bit packing
+  // -----------
+  uint8_t c[13];
+  jt9_bit_packing(message, c);
+
+  // Convolutional Encoding
+  // ---------------------
+  uint8_t s[JT4_SYMBOL_COUNT];
+  convolve(c, s, 13, JT4_BIT_COUNT);
+
+  // Interleaving
+  // ------------
+  jt9_interleave(s);
+  memmove(s + 1, s, JT4_BIT_COUNT);
+  s[0] = 0; // Append a 0 bit to start of sequence
+
+  // Merge with sync vector
+  // ----------------------
+  jt4_merge_sync_vector(s, symbols);
+}
+
 /*
  * wspr_encode(char * call, char * loc, uint8_t dbm, uint8_t * symbols)
  *
@@ -135,7 +171,6 @@ void JTEncode::jt9_encode(char * message, uint8_t * symbols)
  *  Ensure that you pass a uint8_t array of size WSPR_SYMBOL_COUNT to the method.
  *
  */
-
 void JTEncode::wspr_encode(char * call, char * loc, uint8_t dbm, uint8_t * symbols)
 {
     // Ensure that the message text conforms to standards
@@ -655,6 +690,27 @@ void JTEncode::jt9_merge_sync_vector(uint8_t * g, uint8_t * symbols)
   }
 }
 
+void JTEncode::jt4_merge_sync_vector(uint8_t * g, uint8_t * symbols)
+{
+  uint8_t i;
+  const uint8_t sync_vector[JT4_SYMBOL_COUNT] =
+	{0, 0, 0, 0, 1, 1, 0, 0, 0, 1, 1, 0, 1, 1, 0, 0, 1, 0, 1, 0, 0, 0,
+   0, 0, 0, 0, 1, 1, 0, 0, 0 ,0 ,0 ,0 ,0 ,0 ,0 ,0 ,0 ,0 ,1 ,0 ,1 ,1,
+   0, 1, 1, 0, 1, 0, 1, 1, 1, 1, 1, 0, 1, 0, 0, 0, 1, 0, 0, 1, 0, 0,
+   1, 1, 1, 1, 1, 0, 0, 0, 1, 0, 1, 0, 0, 0, 1, 1, 1, 1, 0, 1, 1, 0,
+   0, 1, 0, 0, 0, 1, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 1, 1, 1, 1, 0,
+   1, 0, 1, 0, 1, 1, 0, 1, 0, 1, 0, 1, 1, 1, 0, 0, 1, 0, 1, 1, 0, 1,
+   1, 1, 1, 0, 0, 0, 0, 1, 1, 0, 1, 1, 0, 0, 0, 1, 1, 1, 0, 1, 1, 1,
+   0, 1, 1, 1, 0, 0, 1, 0, 0, 0, 1, 1, 0, 1, 1, 0, 0, 1, 0, 0, 0, 1,
+   1, 1, 1, 1, 1, 0, 0, 1, 1, 0, 0, 0, 0, 1, 1, 0, 0, 0, 1, 0, 1, 1,
+   0, 1, 1, 1, 1, 0, 1, 0, 1};
+
+	for(i = 0; i < JT4_SYMBOL_COUNT; i++)
+	{
+		symbols[i] = sync_vector[i] + (2 * g[i]);
+	}
+}
+
 void JTEncode::wspr_merge_sync_vector(uint8_t * g, uint8_t * symbols)
 {
   uint8_t i;

JTEncode.h

@@ -28,12 +28,14 @@
 
 #define JT65_SYMBOL_COUNT                   126
 #define JT9_SYMBOL_COUNT                    85
+#define JT4_SYMBOL_COUNT                    207
 #define WSPR_SYMBOL_COUNT                   162
 
 #define JT65_ENCODE_COUNT                   63
 #define JT9_ENCODE_COUNT                    69
 
 #define JT9_BIT_COUNT                       206
+#define JT4_BIT_COUNT                       206
 #define WSPR_BIT_COUNT                      162
 
 class JTEncode
@@ -42,6 +44,7 @@ class JTEncode
   JTEncode(void);
   void jt65_encode(char *, uint8_t *);
   void jt9_encode(char *, uint8_t *);
+  void jt4_encode(char *, uint8_t *);
   void wspr_encode(char *, char *, uint8_t, uint8_t *);
 private:
   uint8_t jt_code(char);
@@ -59,6 +62,7 @@ class JTEncode
   void jt_gray_code(uint8_t *, uint8_t);
   void jt65_merge_sync_vector(uint8_t *, uint8_t *);
   void jt9_merge_sync_vector(uint8_t *, uint8_t *);
+  void jt4_merge_sync_vector(uint8_t *, uint8_t *);
   void wspr_merge_sync_vector(uint8_t *, uint8_t *);
   void convolve(uint8_t *, uint8_t *, uint8_t, uint8_t);
   void rs_encode(uint8_t *, uint8_t *);

README.md

@@ -70,7 +70,7 @@ During transmit, the proper class method is chosen based on the desired mode, th
       break;
     }
 
-Once the channel symbols have been generate, it is a simple matter of transmitting them in sequence, each of the correct amount of time:
+Once the channel symbols have been generated, it is a simple matter of transmitting them in sequence, each the correct amount of time:
 
     // Now transmit the channel symbols
     for(i = 0; i < symbol_count; i++)

examples/Si5351JTDemo/Si5351JTDemo.ino

@@ -45,24 +45,27 @@
 // Mode defines
 #define JT9_TONE_SPACING        174           // ~1.74 Hz
 #define JT65_TONE_SPACING       269           // ~2.69 Hz
+#define JT4_TONE_SPACING        437           // ~4.37 Hz
 #define WSPR_TONE_SPACING       146           // ~1.46 Hz
 
-#define JT9_CTC                 9000         // CTC value for JT9-1
-#define JT65_CTC                5812         // CTC value for JT65A
-#define WSPR_CTC                10672        // CTC value for WSPR  
+#define JT9_CTC                 9000          // CTC value for JT9-1
+#define JT65_CTC                5812          // CTC value for JT65A
+#define JT4_CTC                 3578          // CTC value for JT4
+#define WSPR_CTC                10672         // CTC value for WSPR  
 
 #define JT9_DEFAULT_FREQ        14078600UL
 #define JT65_DEFAULT_FREQ       14077500UL
+#define JT4_DEFAULT_FREQ        14077500UL
 #define WSPR_DEFAULT_FREQ       14097100UL
 
-#define DEFAULT_MODE            MODE_JT65
+#define DEFAULT_MODE            MODE_JT4
 
 // Hardware defines
 #define BUTTON                  12
 #define LED_PIN                 13
 
 // Enumerations
-enum mode {MODE_JT9, MODE_JT65, MODE_WSPR};
+enum mode {MODE_JT9, MODE_JT65, MODE_JT4, MODE_WSPR};
 
 // Class instantiation
 Si5351 si5351;
@@ -107,6 +110,9 @@ void encode()
   case MODE_JT65:
     jtencode.jt65_encode(message, tx_buffer);
     break;
+  case MODE_JT4:
+    jtencode.jt4_encode(message, tx_buffer);
+    break;
   case MODE_WSPR:
     jtencode.wspr_encode(call, loc, dbm, tx_buffer);
     break;
@@ -157,6 +163,12 @@ void setup()
     symbol_count = JT65_SYMBOL_COUNT; // From the library defines
     tone_spacing = JT65_TONE_SPACING;
     break;
+  case MODE_JT4:
+    freq = JT4_DEFAULT_FREQ;
+    ctc = JT4_CTC;
+    symbol_count = JT4_SYMBOL_COUNT; // From the library defines
+    tone_spacing = JT4_TONE_SPACING;
+    break;
   case MODE_WSPR:
     freq = WSPR_DEFAULT_FREQ;
     ctc = WSPR_CTC;
@@ -168,7 +180,7 @@ void setup()
   // Initialize the Si5351
   // Change the 2nd parameter in init if using a ref osc other
   // than 25 MHz
-  si5351.init(SI5351_CRYSTAL_LOAD_8PF, 0);
+  si5351.init(SI5351_VARIANT_A3, SI5351_CRYSTAL_LOAD_8PF, 0);
 
   // Set CLK0 output
   si5351.set_correction(0);