From 588d3ecbaad82c3b600761e915dca48260ef422f Mon Sep 17 00:00:00 2001
From: DJ2LS <75909252+DJ2LS@users.noreply.github.com>
Date: Wed, 11 Aug 2021 22:05:28 +0200
Subject: [PATCH] delay between TX and RX

necessary so we are not sending until other station is in RX mode
---
 tnc/data_handler.py | 13 +++++++++++--
 tnc/static.py       |  2 ++
 2 files changed, 13 insertions(+), 2 deletions(-)

diff --git a/tnc/data_handler.py b/tnc/data_handler.py
index 3410ad84..e312bc09 100644
--- a/tnc/data_handler.py
+++ b/tnc/data_handler.py
@@ -598,7 +598,11 @@ def arq_received_data_channel_opener(data_in):
     connection_frame[3:9] = static.MYCALLSIGN
     connection_frame[12:13] = bytes([static.ARQ_DATA_CHANNEL_MODE])
 
-
+    # wait before sending so we can sure, other station is ready for TX
+    wait_until_transmit = time.time() + static.TIME_BETWEEN_RX_TX
+    while time.time() < wait_until_transmit:
+        pass
+        
     modem.transmit_signalling(connection_frame)
     #modem.transmit_signalling(connection_frame)
     while static.CHANNEL_STATE == 'SENDING_SIGNALLING':
@@ -668,7 +672,12 @@ def received_ping(data_in):
     ping_frame[1:2] = static.DXCALLSIGN_CRC8
     ping_frame[2:3] = static.MYCALLSIGN_CRC8
     ping_frame[3:9] = static.MYGRID
-
+    
+    # wait before sending so we can sure, other station is ready for TX
+    wait_until_transmit = time.time() + static.TIME_BETWEEN_RX_TX
+    while time.time() < wait_until_transmit:
+        pass
+        
     # wait while sending....
     modem.transmit_signalling(ping_frame)
     #modem.transmit_signalling(ping_frame)
diff --git a/tnc/static.py b/tnc/static.py
index f7b13a14..01e92637 100644
--- a/tnc/static.py
+++ b/tnc/static.py
@@ -67,6 +67,8 @@ HAMLIB_SERIAL_SPEED = '9600'
 HAMLIB_FREQUENCY = 0
 HAMLIB_MODE = ''
 HAMLIB_BANDWITH = 0
+
+TIME_BETWEEN_RX_TX = 1 # time between TX and RX in seconds
 # -------------------------
 # FreeDV Defaults
 FREEDV_RECEIVE = True