Diff: main.cpp

Revision:

3:33d80761aa06

Parent:

2:1f19f8e52c75

Child:

4:ed77fd381cc5

--- a/main.cpp	Sat Jan 11 05:55:54 2014 +0000
+++ b/main.cpp	Sat Jan 11 18:48:08 2014 +0000
@@ -10,15 +10,18 @@
 #define GPS_CB_SIZE (16) /* size of gps circular buffer in characters */
 #define RTTY_CB_SIZE (2048) /* characters in rtty buffer */
 #define GPS_BAUD (9600) /* gps serial port speed in bps */
-#define RADIO_TX_WAIT (5000) /* time between radio transmissions in ms */
-#define RADIO_KEYUP_DELAY (1000) /* time to wait for radio transmitter to turn on */
-#define PRINT_NMEA_WAIT (2000) /* time between console debug messages */
-#define AUDIO_FS (22050) /* audio sample rate in hz */
-#define RTTY_BAUD (45.45) /* rtty bit rate in bps */
-#define MARK_FREQ (2295) /* mark frequency (1) in hz */
-#define SPACE_FREQ (2125) /* space frequency (0) in hz */
-#define AUDIO_VOL (0.25) /* range 0-1 */
-#define RTTY_NUM_ZEROS (3) /* number of empty characters to append before each rtty message */
+#define RADIO_TX_WAIT (1000) /* time between radio transmissions in ms */
+#define PRINT_NMEA_WAIT (2000) /* time between console debug messages in ms */
+#define CALLSIGN_WAIT (600) /* time between sending amateur radio callsign in s */
+#define AUDIO_FS (8000) /* audio sample rate in hz */
+#define RTTY_BAUD (110) /* rtty bit rate in bps */
+#define MARK_FREQ (2850) /* mark frequency (1) in hz */
+#define SPACE_FREQ (2000) /* space frequency (0) in hz */
+#define AUDIO_VOL (1) /* range 0-1 */
+#define RTTY_NUM_ZEROS_BEFORE (25) /* number of empty characters to append before each rtty message. helps receivers sync. */
+#define RTTY_NUM_ZEROS_AFTER (8) /* number of empty characters to append after each rtty message. */
+#define CALLSIGN "KC0WYS" /* my amateur radio callsign */
+#define CALLSIGN_TAG "HAMID" /* 5-character tag used in the fake nmea sentence */
 
 using namespace std;
 
@@ -99,7 +102,7 @@
         if(angle > 2 * PI) angle -= 2*PI;
         dac = (arm_sin_f32(angle) + 1.0) / 2.0 * AUDIO_VOL; // write sample to dac
         ptt = 0;
-        rtty_led = 1;
+        rtty_led = !rtty_led;
     } else {
         dac = 0;
         ptt = 1;
@@ -128,17 +131,7 @@
     }
 }
 
-// Adds empty characters to RTTY buffer.
-void rtty_add_padding()
-{
-    for(int i = 0; i < RTTY_NUM_ZEROS; ++i) {
-        if(++r_cb_thr_i >= RTTY_CB_SIZE) r_cb_thr_i = 0; // incr/loop circular buffer index
-        r_cb[r_cb_thr_i] = 0; // append a zero
-    }
-}
-
-// Adds NMEA sentences periodically to a buffer for the other RTTY
-// functions to process.
+// Adds NMEA sentences periodically to a buffer for the other RTTY functions to process.
 void rtty_tx_thread(void const *argument)
 {
     while(1) {
@@ -148,18 +141,37 @@
         for (map<string,string>::iterator iter = nmea_data.begin(); iter != nmea_data.end(); ++iter) {
             txbuf << (iter->second); // fill the packet with the most recent nmea sentences
         }
+        nmea_data.clear(); // empty the map
         nmea_data_mutex.unlock();
-        rtty_add_padding(); // pad message with empty characters
+        for(int i = 0; i < RTTY_NUM_ZEROS_BEFORE; ++i) { // add empty characters
+            if(++r_cb_thr_i >= RTTY_CB_SIZE) r_cb_thr_i = 0; // incr/loop circular buffer index
+            r_cb[r_cb_thr_i] = 0; // append a zero character
+        }
         for(const char* it = txbuf.str().c_str(); *it; ++it) { // add all characters to buffer
             if(++r_cb_thr_i >= RTTY_CB_SIZE) r_cb_thr_i = 0; // incr/loop circular buffer index
             r_cb[r_cb_thr_i] = *it;
         }
-        rtty_add_padding();
+        for(int i = 0; i < RTTY_NUM_ZEROS_AFTER; ++i) { // add empty characters
+            if(++r_cb_thr_i >= RTTY_CB_SIZE) r_cb_thr_i = 0; // incr/loop circular buffer index
+            r_cb[r_cb_thr_i] = 0; // append a zero character
+        }
         while(!txen) Thread::wait(100); // wait for transmission to start
         while( txen) Thread::wait(100); // wait for transmission to end
     }
 }
 
+// Periodically inserts HAM radio callsign into NMEA sentence map.
+// Required by FCC to send callsign at least every 30 minutes.
+void insert_callsign_thread(void const *argument)
+{
+    while(1) {
+        nmea_data_mutex.lock();
+        nmea_data[CALLSIGN_TAG] = "$" CALLSIGN_TAG "," CALLSIGN "," CALLSIGN "," CALLSIGN ",*00\r\n"; // dummy nmea sentence
+        nmea_data_mutex.unlock();
+        for(int i = 0; i < CALLSIGN_WAIT; ++i) Thread::wait(1000); // wait for CALLSIGN_WAIT seconds
+    }
+}
+
 // Writes debug messages periodically to the console. Useful for debug.
 void print_nmea_thread(void const *argument)
 {
@@ -180,6 +192,7 @@
     Thread gps_thread(gps_rx_thread); // gps receive thread
     Thread rtty_thread(rtty_tx_thread); // rtty transmit thread
     Thread print_thread(print_nmea_thread); // debug print thread
+    Thread callsign_thread(insert_callsign_thread); // amateur callsign thread
     gps.baud(GPS_BAUD); // set gps bit rate
     gps.attach(&gps_rx_isr); // set up gps receive interrupt service routine
     sample_tick.attach_us(&rtty_sample_tick,1000000/AUDIO_FS); // begin generating audio