From: batt <batt@38d2e660-2303-0410-9eaa-f027e97ec537>
Date: Fri, 9 Oct 2009 21:48:32 +0000 (+0000)
Subject: Add support for preamble/trailer before starting real data transmission: this give... 
X-Git-Tag: 2.3.0~30
X-Git-Url: https://codewiz.org/gitweb?a=commitdiff_plain;h=441c294a809638c22c77ae37c8e7bb57cf57f126;p=bertos.git

Add support for preamble/trailer before starting real data transmission: this give the TX rig some time to switch to/from transmit mode.

git-svn-id: https://src.develer.com/svnoss/bertos/trunk@3053 38d2e660-2303-0410-9eaa-f027e97ec537
---

diff --git a/bertos/cfg/cfg_afsk.h b/bertos/cfg/cfg_afsk.h
index 791916d2..f5a27e42 100644
--- a/bertos/cfg/cfg_afsk.h
+++ b/bertos/cfg/cfg_afsk.h
@@ -62,7 +62,7 @@
  * $WIZ$ type = "int"
  * $WIZ$ min = 2
  */
-#define CONFIG_AFSK_TX_BUFLEN 256
+#define CONFIG_AFSK_TX_BUFLEN 32
 
 /**
  * AFSK DAC sample rate for modem outout.
@@ -78,4 +78,21 @@
  */
 #define CONFIG_AFSK_RXTIMEOUT 0
 
+
+/**
+ * AFSK Preamble length in [ms], before starting transmissions.
+ * $WIZ$ type = "int"
+ * $WIZ$ min = 1
+ */
+#define CONFIG_AFSK_PREAMBLE_LEN 300UL
+
+
+
+/**
+ * AFSK Trailer length in [ms], before stopping transmissions.
+ * $WIZ$ type = "int"
+ * $WIZ$ min = 1
+ */
+#define CONFIG_AFSK_TRAILER_LEN 50UL
+
 #endif /* CFG_AFSK_H */
diff --git a/bertos/net/afsk.c b/bertos/net/afsk.c
index d2291262..e516a3f3 100644
--- a/bertos/net/afsk.c
+++ b/bertos/net/afsk.c
@@ -164,6 +164,9 @@ static uint8_t hdlc_bit_idx;
 #define BIT_DIFFER(bitline1, bitline2) (((bitline1) ^ (bitline2)) & 0x01)
 #define EDGE_FOUND(bitline)            BIT_DIFFER((bitline), (bitline) >> 1)
 
+static uint16_t preamble_len;
+static uint16_t trailer_len;
+
 static void hdlc_parse(bool bit)
 {
 	demod_bits <<= 1;
@@ -342,8 +345,10 @@ static void afsk_txStart(void)
 		phase_acc = 0;
 		stuff_cnt = 0;
 		sending = true;
+		preamble_len = DIV_ROUND(CONFIG_AFSK_PREAMBLE_LEN * BITRATE, 8000);
 		AFSK_DAC_IRQ_START();
 	}
+	ATOMIC(trailer_len  = DIV_ROUND(CONFIG_AFSK_TRAILER_LEN  * BITRATE, 8000));
 }
 
 #define BIT_STUFF_LEN 5
@@ -358,7 +363,7 @@ DEFINE_AFSK_DAC_ISR()
 		if (tx_bit == 0)
 		{
 			/* We have just finished transimitting a char, get a new one. */
-			if (fifo_isempty(&tx_fifo))
+			if (fifo_isempty(&tx_fifo) && trailer_len == 0)
 			{
 				AFSK_DAC_IRQ_STOP();
 				sending = false;
@@ -375,7 +380,25 @@ DEFINE_AFSK_DAC_ISR()
 					stuff_cnt = 0;
 
 				bit_stuff = true;
-				curr_out = fifo_pop(&tx_fifo);
+
+				/*
+				 * Handle preamble and trailer
+				 */
+				if (preamble_len == 0)
+				{
+					if (fifo_isempty(&tx_fifo))
+					{
+						trailer_len--;
+						curr_out = HDLC_FLAG;
+					}
+					else
+						curr_out = fifo_pop(&tx_fifo);
+				}
+				else
+				{
+					preamble_len--;
+					curr_out = HDLC_FLAG;
+				}
 
 				/* Handle char escape */
 				if (curr_out == AX25_ESC)