Full Duplex.

Author: wb2osz

CHANGES.md

@@ -13,6 +13,8 @@ This is a snapshot of ongoing development towards version of 1.5.  Some features
 
 - PTT using GPIO pin of CM108/CM119 (e.g. DMK URI, RB-USB RIM)
 
+- Full Duplex operation.  (Put "FULLDUP ON" in channel section of configuration file.)
+
 
 ### Bugs Fixed: ###
 

audio.h

@@ -281,7 +281,10 @@ struct audio_s {
 					/* are done sending the data.  This is to avoid */
 					/* dropping PTT too soon and chopping off the end */
 					/* of the frame.  Again 10 mS units. */
-					/* At this point, I'm thinking of 10 as the default. */
+					/* At this point, I'm thinking of 10 (= 100 mS) as the default */
+					/* because we're not quite sure when the soundcard audio stops. */
+
+	    int fulldup;		/* Full Duplex. */
 
 	} achan[MAX_CHANS];
 
@@ -368,7 +371,7 @@ struct audio_s {
 #define DEFAULT_PERSIST		63
 #define DEFAULT_TXDELAY		30
 #define DEFAULT_TXTAIL		10	
-
+#define DEFAULT_FULLDUP		0
 
 /* 
  * Note that we have two versions of these in audio.c and audio_win.c.

config.c

@@ -794,6 +794,7 @@ void config_init (char *fname, struct audio_s *p_audio_config,
 	  p_audio_config->achan[channel].persist = DEFAULT_PERSIST;				
 	  p_audio_config->achan[channel].txdelay = DEFAULT_TXDELAY;				
 	  p_audio_config->achan[channel].txtail = DEFAULT_TXTAIL;				
+	  p_audio_config->achan[channel].fulldup = DEFAULT_FULLDUP;
 	}
 
 	/* First channel should always be valid. */
@@ -1778,13 +1779,13 @@ void config_init (char *fname, struct audio_s *p_audio_config,
 										// User can override for special cases.
 	      p_audio_config->achan[channel].octrl[ot].ptt_invert = 0;		// High for transmit.
 	      strcpy (p_audio_config->achan[channel].octrl[ot].ptt_device, "");
- 
+
 	      // Try to find PTT device for audio output device.
 	      // Simplifiying assumption is that we have one radio per USB Audio Adapter.
 	      // Failure at this point is not an error.
 	      // See if config file sets it explicitly before complaining.
 
- 	      cm108_find_ptt (p_audio_config->adev[ACHAN2ADEV(channel)].adevice_out,
+	      cm108_find_ptt (p_audio_config->adev[ACHAN2ADEV(channel)].adevice_out,
 				p_audio_config->achan[channel].octrl[ot].ptt_device,
 				(int)sizeof(p_audio_config->achan[channel].octrl[ot].ptt_device));
 
@@ -1923,7 +1924,7 @@ void config_init (char *fname, struct audio_s *p_audio_config,
  *
  * TXINH - TX holdoff input
  *
- * xxx GPIO [-]gpio-num (only type supported yet)
+ * TXINH GPIO [-]gpio-num (only type supported so far)
  */
 
 	  else if (strcasecmp(t, "TXINH") == 0) {
@@ -1966,7 +1967,7 @@ void config_init (char *fname, struct audio_s *p_audio_config,
 
 
 /*
- * DWAIT 		- Extra delay for receiver squelch.
+ * DWAIT n		- Extra delay for receiver squelch. n = 10 mS units.
  */
 
 	  else if (strcasecmp(t, "DWAIT") == 0) {
@@ -1990,7 +1991,7 @@ void config_init (char *fname, struct audio_s *p_audio_config,
 	  }
 
 /*
- * SLOTTIME 		- For non-digipeat transmit delay timing.
+ * SLOTTIME n		- For non-digipeat transmit delay timing. n = 10 mS units.
  */
 
 	  else if (strcasecmp(t, "SLOTTIME") == 0) {
@@ -2038,7 +2039,7 @@ void config_init (char *fname, struct audio_s *p_audio_config,
 	  }
 
 /*
- * TXDELAY 		- For transmit delay timing.
+ * TXDELAY n		- For transmit delay timing. n = 10 mS units.
  */
 
 	  else if (strcasecmp(t, "TXDELAY") == 0) {
@@ -2062,7 +2063,7 @@ void config_init (char *fname, struct audio_s *p_audio_config,
 	  }
 
 /*
- * TXTAIL 		- For transmit timing.
+ * TXTAIL n		- For transmit timing. n = 10 mS units.
  */
 
 	  else if (strcasecmp(t, "TXTAIL") == 0) {
@@ -2085,6 +2086,30 @@ void config_init (char *fname, struct audio_s *p_audio_config,
    	    }
 	  }
 
+/*
+ * FULLDUP  {on|off} 		- Full Duplex
+ */
+	  else if (strcasecmp(t, "FULLDUP") == 0) {
+
+	    t = split(NULL,0);
+	    if (t == NULL) {
+	      text_color_set(DW_COLOR_ERROR);
+	      dw_printf ("Line %d: Missing parameter for FULLDUP command.  Expecting ON or OFF.\n", line);
+	      continue;
+	    }
+	    if (strcasecmp(t, "ON") == 0) {
+	      p_audio_config->achan[channel].fulldup = 1;
+	    }
+	    else if (strcasecmp(t, "OFF") == 0) {
+	      p_audio_config->achan[channel].fulldup = 0;
+	    }
+	    else {
+	      p_audio_config->achan[channel].fulldup = 0;
+	      text_color_set(DW_COLOR_ERROR);
+	      dw_printf ("Line %d: Expected ON or OFF for FULLDUP.\n", line);
+	    }
+	  }
+
 /*
  * SPEECH  script 
  *

doc/User-Guide.pdf

@@ -58,7 +58,8 @@
  *						Spec says it is obsolete but Xastir
  *						sends it and we respect it.
  *
- *			_5	FullDuplex	Ignored.
+ *			_5	FullDuplex	Full Duplex.  Transmit immediately without
+ *						waiting for channel to be clear.
  *		
  *			_6	SetHardware	TNC specific.
  *
@@ -644,7 +645,8 @@ void kiss_process_msg (unsigned char *kiss_msg, int kiss_len, int debug, int cli
         case KISS_CMD_FULLDUPLEX:			/* 5 = FullDuplex */
 
           text_color_set(DW_COLOR_INFO);
-	  dw_printf ("KISS protocol set FullDuplex = %d, port %d - Ignored\n", kiss_msg[1], port);
+	  dw_printf ("KISS protocol set FullDuplex = %d, port %d\n", kiss_msg[1], port);
+	  xmit_set_fulldup (port, kiss_msg[1]);
 	  break;
 
         case KISS_CMD_SET_HARDWARE:			/* 6 = TNC specific */

kiss_frame.c

@@ -2,7 +2,7 @@
 //
 //    This file is part of Dire Wolf, an amateur radio packet TNC.
 //
-//    Copyright (C) 2011, 2013, 2014, 2015, 2016  John Langner, WB2OSZ
+//    Copyright (C) 2011, 2013, 2014, 2015, 2016, 2017  John Langner, WB2OSZ
 //
 //    This program is free software: you can redistribute it and/or modify
 //    it under the terms of the GNU General Public License as published by
@@ -101,6 +101,8 @@ static int xmit_txtail[MAX_CHANS];	/* Amount of time to keep transmitting after
 					/* dropping PTT too soon and chopping off the end */
 					/* of the frame.  Again 10 mS units. */
 
+static int xmit_fulldup[MAX_CHANS];	/* Full duplex if non-zero. */
+
 static int xmit_bits_per_sec[MAX_CHANS];	/* Data transmission rate. */
 					/* Often called baud rate which is equivalent in */
 					/* this case but could be different with other */
@@ -137,7 +139,7 @@ static dw_mutex_t audio_out_dev_mutex[MAX_ADEVS];
 
 
 
-static int wait_for_clear_channel (int channel, int slotttime, int persist);
+static int wait_for_clear_channel (int channel, int slotttime, int persist, int fulldup);
 static void xmit_ax25_frames (int c, int p, packet_t pp, int max_bundle);
 static int send_one_frame (int c, int p, packet_t pp);
 static void xmit_speech (int c, packet_t pp);
@@ -218,6 +220,7 @@ void xmit_init (struct audio_s *p_modem, int debug_xmit_packet)
 	  xmit_persist[j] = p_modem->achan[j].persist;
 	  xmit_txdelay[j] = p_modem->achan[j].txdelay;
 	  xmit_txtail[j] = p_modem->achan[j].txtail;
+	  xmit_fulldup[j] = p_modem->achan[j].fulldup;
 	}
 
 #if DEBUG
@@ -306,6 +309,7 @@ void xmit_init (struct audio_s *p_modem, int debug_xmit_packet)
  *		xmit_set_persist
  *		xmit_set_slottime
  *		xmit_set_txtail
+ *		xmit_set_fulldup
  *				
  *
  * Purpose:     The KISS protocol, and maybe others, can specify
@@ -355,6 +359,13 @@ void xmit_set_txtail (int channel, int value)
 	}
 }
 
+void xmit_set_fulldup (int channel, int value)
+{
+	if (channel >= 0 && channel < MAX_CHANS) {
+	  xmit_fulldup[channel] = value;
+	}
+}
+
 
 /*-------------------------------------------------------------------
  *
@@ -490,7 +501,7 @@ static void * xmit_thread (void *arg)
  * If there is something in the high priority queue, begin transmitting immediately.
  * Otherwise, wait a random amount of time, in hopes of minimizing collisions.
  */
-	    ok = wait_for_clear_channel (chan, xmit_slottime[chan], xmit_persist[chan]);
+	    ok = wait_for_clear_channel (chan, xmit_slottime[chan], xmit_persist[chan], xmit_fulldup[chan]);
 
 	    prio = TQ_PRIO_1_LO;
 	    pp = tq_remove (chan, TQ_PRIO_0_HI);
@@ -670,6 +681,8 @@ static void * xmit_thread (void *arg)
  *		Once we have control of the channel, we might as well keep going.
  *		[High] Priority frames will always go to head of the line,
  *
+ * Version 1.5:	Add full duplex option.
+ *
  *--------------------------------------------------------------------*/
 
 
@@ -1231,12 +1244,19 @@ static void xmit_dtmf (int c, packet_t pp, int speed)
  *		slottime - 	Amount of time to wait for each iteration
  *				of the waiting algorithm.  10 mSec units.
  *
- *		persist -	Probability of transmitting 
+ *		persist -	Probability of transmitting.
+ *
+ *		fulldup -	Full duplex.  Just start sending immediately.
  *
  * Returns:	1 for OK.  0 for timeout.
  *
  * Description:	New in version 1.2: also obtain a lock on audio out device.
  *
+ *		New in version 1.5: full duplex.
+ *		Just start transmitting rather than waiting for clear channel.
+ *		This would only be appropriate when transmit and receive are
+ *		using different radio freqencies.  e.g.  VHF up, UHF down satellite.
+ *
  * Transmit delay algorithm:
  *
  *		Wait for channel to be clear.
@@ -1271,10 +1291,17 @@ static void xmit_dtmf (int c, packet_t pp, int speed)
 #define WAIT_TIMEOUT_MS (60 * 1000)	
 #define WAIT_CHECK_EVERY_MS 10
 
-static int wait_for_clear_channel (int chan, int slottime, int persist)
+static int wait_for_clear_channel (int chan, int slottime, int persist, int fulldup)
 {
 	int n = 0;
 
+/*
+ * For dull duplex we skip the channel busy check and random wait.
+ * We still need to wait if operating in stereo and the other audio
+ * half is busy.
+ */
+	if ( ! fulldup) {
+
 start_over_again:
 
 	while (hdlc_rec_data_detect_any(chan)) {
@@ -1318,6 +1345,7 @@ static int wait_for_clear_channel (int chan, int slottime, int persist)
 	    break;
  	  }	
 	}
+	}
 
 /*
  * This is to prevent two channels from transmitting at the same time

xmit.c

@@ -16,6 +16,8 @@ extern void xmit_set_slottime (int channel, int value);
 
 extern void xmit_set_txtail (int channel, int value);
 
+extern void xmit_set_fulldup (int channel, int value);
+
 
 extern int xmit_speak_it (char *script, int c, char *msg);