Quisk version 4.2.55

Added introductory information about Quisk software defined radio, including its features and support links.

CHANGELOG.txt

@@ -1,3 +1,9 @@
+Quisk Version 4.2.55  October 2026
+==================================
+Karl Heinz, K5KHK, provided a patche to fix the AC2YD remote control head. He provided another patch
+to fix Hamlib control when using WSJT-X improved. He added a mic jitter buffer to the remote control
+head so it works over WiFi. Thanks Karl!
+
 Quisk Version 4.2.54  August 2026
 =================================
 Quisk can now accept audio samples for Tx from TCI at rates 48000, 24000, 12000 and 8000. Please test.

README.md

@@ -0,0 +1,12 @@
+# Quisk Software Defined Radio
+
+Quisk is a software defined radio transceiver that runs on a PC or on a single board computer such as a Raspberry Pi.
+It is written in Python and C.
+It works with various kinds of radio hardware such as SoftRock, Hermes Lite 2,
+the SDR-IQ by RfSpace, and with network UDP samples.
+Quisk is easily extensible by writing your own hardware file in Python.
+
+I wrote Quisk back in 2008, and I have been maintaining it ever since.
+For questions and support, please visit the group https://groups.io/g/n2adr-sdr.
+
+For more information see https://james.ahlstrom.name/quisk.

__init__.py

@@ -1,2 +1,2 @@
-#Quisk version 4.2.54
+#Quisk version 4.2.55
 from .quisk import main

ac2yd/remote.c

@@ -53,6 +53,41 @@ static int control_head_data_width;					// app.data_width of control head for gr
 static int packets_sent;
 static int packets_recd;
 
+///// The jitter buffer is thanks to Karl Heinz - K5KHK
+// Jitter buffer for the microphone samples received from the control head.  The network can hold
+// packets for 100 msec or more (Wi-Fi power saving and scanning) and then deliver them in a burst,
+// but the Hermes Tx buffer only has 50 msec of slack.  Without a buffer here, each late burst is an
+// underflow (a gap on the air) followed by an overflow (discarded samples).  So buffer mic_jb_target
+// frames before playing, and then release them at a steady MIC_JB_RATE.
+// The buffer adds its delay to the transmit audio, so it is off unless the configuration item
+// remote_radio_mic_jitter_ms is set.  When it is off, samples are passed on as they arrive.
+#define MIC_JB_RATE		8000	// frames per second sent by the control head
+#define MIC_JB_SIZE		8000	// ring buffer size in stereo frames
+#define MIC_JB_MAX_MS	500		// largest configurable delay; MIC_JB_SIZE must hold this plus MIC_JB_EXTRA
+#define MIC_JB_EXTRA	2000	// trim back to mic_jb_target above mic_jb_target + this (clock drift): 250 msec
+#define MIC_JB_IDLE		0.5		// seconds without packets that end a transmission
+
+static int16_t mic_jb[MIC_JB_SIZE * 2];
+static int mic_jb_target;	// frames to buffer before playing, from remote_radio_mic_jitter_ms; zero for off
+static int mic_jb_read, mic_jb_count, mic_jb_playing, mic_jb_starved;
+static int mic_jb_underruns, mic_jb_overruns;
+static double mic_jb_time, mic_jb_frac, mic_jb_last_packet;
+
+static void mic_jb_reset(void)
+{
+	int msec;
+
+	msec = QuiskGetConfigInt("remote_radio_mic_jitter_ms", 0);
+	if (msec < 0)
+		msec = 0;
+	else if (msec > MIC_JB_MAX_MS)
+		msec = MIC_JB_MAX_MS;
+	mic_jb_target = msec * MIC_JB_RATE / 1000;
+	mic_jb_read = mic_jb_count = mic_jb_playing = mic_jb_starved = 0;
+	mic_jb_underruns = mic_jb_overruns = 0;
+	mic_jb_frac = 0;
+}
+
 // Receive stereo 16-bit pcm radio speaker sound on the control head via UDP
 int read_remote_radio_sound_socket(complex double * cSamples)
 {
@@ -117,9 +152,9 @@ int read_remote_radio_sound_socket(complex double * cSamples)
 // Receive stereo 16-bit pcm microphone samples at the remote radio via UDP
 int read_remote_mic_sound_socket(complex double * cSamples)
 {
-	int i, bytes, nInt16, nSamples;
+	int i, j, bytes, nInt16, nSamples, nFrames;
 	int16_t buf[UDP_SEND_INT16];
-	double samp_r, samp_l;
+	double now, due;
 	struct timeval tm_wait;
 	fd_set fds;
 	static struct quisk_cHB45Filter HalfBand;
@@ -134,8 +169,8 @@ int read_remote_mic_sound_socket(complex double * cSamples)
 		quisk_filt_cInit(&cFiltInterp3, quiskAudio24p3Coefs, sizeof(quiskAudio24p3Coefs)/sizeof(double));
 	}
 
-	// read all available packets, one per loop
-	nSamples = 0;
+	// read all available packets into the jitter buffer, one per loop
+	now = QuiskTimeSec();
 	while (1) {
 		tm_wait.tv_sec = 0;
 		tm_wait.tv_usec = 0;
@@ -152,15 +187,71 @@ int read_remote_mic_sound_socket(complex double * cSamples)
 			break;
 		}
 		if (bytes > 0) {
+			if (mic_jb_starved) {	// the buffer ran dry; count it unless the transmission had ended
+				mic_jb_starved = 0;
+				if (now - mic_jb_last_packet < MIC_JB_IDLE)
+					mic_jb_underruns++;
+			}
+			mic_jb_last_packet = now;
 			nInt16 = bytes / 2;
-			for (i = 0; i < nInt16; i += 2) {
-				samp_r = buf[i];
-				samp_l = buf[i + 1];
-				cSamples[nSamples++] = (samp_r + I * samp_l) / CLIP16 * CLIP32;
+			for (i = 0; i + 1 < nInt16; i += 2) {
+				if (mic_jb_count >= MIC_JB_SIZE) {	// full: drop the oldest frame
+					mic_jb_read = (mic_jb_read + 1) % MIC_JB_SIZE;
+					mic_jb_count--;
+				}
+				j = (mic_jb_read + mic_jb_count) % MIC_JB_SIZE * 2;
+				mic_jb[j] = buf[i];
+				mic_jb[j + 1] = buf[i + 1];
+				mic_jb_count++;
 			}
 		}
 	} // while(1)
 
+	// release the frames that are due since the last call
+	nSamples = 0;
+	if (mic_jb_target == 0) {		// the jitter buffer is off: pass on everything received
+		nFrames = mic_jb_count;
+	}
+	else if ( ! mic_jb_playing) {
+		nFrames = 0;
+		if (mic_jb_count >= mic_jb_target) {
+			mic_jb_playing = 1;
+			mic_jb_time = now;
+			mic_jb_frac = 0;
+		}
+	}
+	else {
+		due = (now - mic_jb_time) * MIC_JB_RATE + mic_jb_frac;
+		if (due < 0)			// the clock was set back
+			due = 0;
+		else if (due > MIC_JB_RATE / 2)	// limit to 0.5 sec, well within SAMP_BUFFER_SIZE after interpolation
+			due = MIC_JB_RATE / 2;
+		mic_jb_time = now;
+		nFrames = (int)due;
+		mic_jb_frac = due - nFrames;
+		if (nFrames > mic_jb_count) {	// ran dry: play what is left, then buffer up again
+			nFrames = mic_jb_count;
+			mic_jb_playing = 0;
+			mic_jb_starved = 1;
+		}
+	}
+	for (i = 0; i < nFrames; i++) {
+		j = mic_jb_read * 2;
+		cSamples[nSamples++] = ((double)mic_jb[j] + I * (double)mic_jb[j + 1]) / CLIP16 * CLIP32;
+		mic_jb_read = (mic_jb_read + 1) % MIC_JB_SIZE;
+	}
+	mic_jb_count -= nFrames;
+	if (mic_jb_target && mic_jb_count > mic_jb_target + MIC_JB_EXTRA) {	// the control head's clock is faster than ours
+		i = mic_jb_count - mic_jb_target;
+		mic_jb_read = (mic_jb_read + i) % MIC_JB_SIZE;
+		mic_jb_count -= i;
+		mic_jb_overruns++;
+	}
+	if ((mic_jb_underruns || mic_jb_overruns) && now - mic_jb_last_packet > MIC_JB_IDLE) {
+		QuiskPrintf("Remote mic jitter buffer: %d underruns, %d overruns\n", mic_jb_underruns, mic_jb_overruns);
+		mic_jb_underruns = mic_jb_overruns = 0;
+	}
+
 	nSamples = quisk_cInterpolate(cSamples, nSamples, &cFiltInterp3, 3);
 	nSamples = quisk_cInterp2HB45(cSamples, nSamples, &HalfBand);
 
@@ -716,6 +807,7 @@ PyObject * quisk_start_remote_radio_remote_sound(PyObject * self, PyObject * arg
 
 	packets_sent = 0;
 	packets_recd = 0;
+	mic_jb_reset();
 
 	return Py_None;
 }
@@ -742,6 +834,7 @@ PyObject * quisk_stop_remote_radio_remote_sound(PyObject * self, PyObject * args
 	control_head_graph_socket_started = 0;
 	remote_radio_graph_socket_started = 0;
 	control_head_data_width = 0;
+	mic_jb_reset();
 
 	QuiskPrintf("total packets sent = %i, recd = %i\n", packets_sent, packets_recd);
 

ac2yd/remote_common.py

@@ -190,10 +190,20 @@ class Remot:	# Remote comtrol base class
       return
     try:	# Read any data from the socket
       text = self.remote_ctl_connection.recv(1024)
-    except:
-      #traceback.print_exc()
+      # Thanks to Karl Heinz - K5KHK
+    except (BlockingIOError, InterruptedError, socket.timeout): # No data available now
+      return
+    except OSError: # For example ConnectionResetError: the Control Head is gone
+      print('Closing Remote Control connection: recv() failed')
+      self.RemoteCtlClose(False)
       return
     else:					# We got some characters
+      if not text: # recv() returns nothing only when the Control Head has closed the connection
+        # Close now rather than waiting for the heartbeat timeout: a Control Head that
+        # crashed or lost its network may have left the transmitter keyed.
+        print('Closing Remote Control connection: closed by Control Head')
+        self.RemoteCtlClose(False)
+        return
       if not isinstance(text, str):
         text = text.decode('utf-8')
       self.received += text
@@ -375,13 +385,22 @@ class Remot:	# Remote comtrol base class
           self.cw_next_keydown = None
 
   def StopTransmit(self):
-    # TODO:  Add code for modes other than CW
+    # PTT code added thanks to Karl Heinz - K5KHK
+    # Called whenever the remote session ends (RemoteCtlClose).  Release everything the
+    # Control Head may have keyed: the CW key and, for voice and digital modes, PTT.
+    # Without the PTT release, a Control Head that disappears while transmitting (a crash,
+    # a lost network, a dead battery) leaves the transmitter keyed until someone unkeys it
+    # at the radio.
     while len(self.cw_event_queue):
       self.cw_event_queue.popleft()
     self.cw_next_event_ts = None
     self.cw_next_keydown = None
     self.cw_key_down = 0
     QS.set_remote_cwkey(0)
+    ptt = getattr(self.app, 'pttButton', None)
+    if ptt and ptt.GetValue():
+      print('Remote Control connection closed while transmitting: releasing PTT')
+      ptt.SetValue(0, True) # Same as releasing PTT at the radio; runs OnButtonPTT
 
   def ProcessRadioBtn(self, command, cmd_text):
     # Large and Small format screens send different button events for radio buttons.

configure.py

@@ -2302,7 +2302,8 @@ class ControlMixin:
         if name in ('hot_key_ptt_toggle', 'hot_key_ptt_if_hidden', 'keyupDelay', 'cwTone', 'pulse_audio_verbose_output',
                     'start_cw_delay', 'start_ssb_delay', 'maximum_tx_secs', 'quisk_serial_cts', 'quisk_serial_dsr',
                     'hot_key_ptt1', 'hot_key_ptt2', 'midi_ptt_toggle', 'TxRxSilenceMsec',
-                    'fixed_tune_offset', 'calibrate_temp_20', 'calibrate_temp_40', 'calibrate_current_0', 'calibrate_current_1'):
+                    'fixed_tune_offset', 'calibrate_temp_20', 'calibrate_temp_40', 'calibrate_current_0', 'calibrate_current_1',
+                    'remote_radio_mic_jitter_ms'):
           setattr(conf, name, x)
           application.ImmediateChange(name)
         elif name[0:4] in ('lin_', 'win_'):

pyproject.toml

@@ -4,7 +4,7 @@ build-backend = "setuptools.build_meta"
 
 [project]
 name = "quisk"
-version = "4.2.54"
+version = "4.2.55"
 requires-python = ">=3.13"
 description = 'QUISK is a Software Defined Radio (SDR) transceiver that can control various radio hardware.'
 license = "GPL-2.0-or-later"

quisk.py

@@ -742,6 +742,7 @@ class HamlibHandlerRig2:	# Test with telnet localhost 4532
     self.vfo = "Main"
     self.split_mode = 0
     self.split_vfo = 'VFO'
+    self.lock_mode = 0
     h = self.Handlers = {}
     h[''] = self.ErrProtocol
     h['dump_state']	= self.DumpState
@@ -765,6 +766,8 @@ class HamlibHandlerRig2:	# Test with telnet localhost 4532
     h['set_split_freq']	= self.SetSplitFreq
     h['get_split_vfo']	= self.GetSplitVfo
     h['set_split_vfo']	= self.SetSplitVfo
+    h['get_lock_mode']	= self.GetLockMode
+    h['set_lock_mode']	= self.SetLockMode
     self.MakeDumpState()
   def MakeDumpState(self):
     dump_state = []
@@ -1009,7 +1012,8 @@ class HamlibHandlerRig2:	# Test with telnet localhost 4532
       self.ErrParam()
     else:
       freq = int(freq + 0.5)
-      self.app.ChangeRxTxFrequency(freq, None)
+      # Like a real radio, keep the mode. Hamlib caches the mode, so the client would not notice a mode change.
+      self.app.ChangeRxTxFrequency(freq, None, keep_mode=True)
   def GetSplitFreq(self):	# The Tx Frequency
     self.Reply('TX Frequency', self.app.txFreq + self.app.VFO, 0)
   def SetSplitFreq(self):	# The Tx Frequency
@@ -1022,7 +1026,7 @@ class HamlibHandlerRig2:	# Test with telnet localhost 4532
     else:
       freq = int(freq + 0.5)
       # This always controls the Tx frequency
-      self.app.ChangeRxTxFrequency(None, freq)
+      self.app.ChangeRxTxFrequency(None, freq, keep_mode=True)
   def GetSplitVfo(self):
     self.Reply('Split', self.split_mode, 'TX VFO', self.split_vfo, 0)
   def SetSplitVfo(self):
@@ -1107,6 +1111,22 @@ class HamlibHandlerRig2:	# Test with telnet localhost 4532
         Lab = label
         diff = df
     self.app.filterButns.SetLabel(Lab, True)
+  # The code for the lock_mode and keep_mode was supplied by Karl Heinz - K5KHK. Thanks Karl!
+  def GetLockMode(self):
+    # Hamlib netrigctl always reads two lines, so an error reply "RPRT -4" makes it wait for its 10 second timeout.
+    # Reply like rigctld with the lock value and then "RPRT 0".
+    if self.extended:
+      self.Reply('Locked', self.lock_mode, 0)
+    else:
+      self.Send("%d\nRPRT 0\n" % self.lock_mode)
+  def SetLockMode(self):
+    lock = self.GetParamNumber()
+    try:
+      self.lock_mode = int(lock)
+    except:
+      self.ErrParam()
+    else:
+      self.Reply(0)
   def GetVfo(self):
     self.Reply('VFO', self.vfo, 0)
   def SetVfo(self):
@@ -6136,7 +6156,7 @@ class App(wx.App):
       self.freqDisplay.Display(self.txFreq + self.VFO)
       self.fldigi_new_freq = self.txFreq + self.VFO
     return change
-  def ChangeRxTxFrequency(self, rx_freq=None, tx_freq=None):
+  def ChangeRxTxFrequency(self, rx_freq=None, tx_freq=None, keep_mode=False):
     if not self.split_rxtx and not tx_freq:
       tx_freq = rx_freq
     if tx_freq:
@@ -6147,7 +6167,7 @@ class App(wx.App):
       else:					# Change the VFO
         vfo = (tx_freq // 5000) * 5000 - 5000
         tune = tx_freq - vfo
-        self.BandFromFreq(tx_freq)
+        self.BandFromFreq(tx_freq, keep_mode)
       self.ChangeHwFrequency(tune, vfo, 'FreqEntry')
     if rx_freq and self.split_rxtx:		# Frequency must be on-screen
       tune = rx_freq - self.VFO
@@ -6337,7 +6357,8 @@ class App(wx.App):
       self.pttButton.Enable(False)
     else:
       self.pttButton.Enable(True)
-  def BandFromFreq(self, frequency):	# Change to a new band based on the frequency
+  def BandFromFreq(self, frequency, keep_mode=False):	# Change to a new band based on the frequency
+    # If keep_mode is True, do not change to the mode saved for the new band.
     if self.screen == self.bandscope_screen:
       return
     try:
@@ -6359,7 +6380,8 @@ class App(wx.App):
           vfo, tune, mode = self.bandState[band]
         except KeyError:
           vfo, tune, mode = (0, 0, 'LSB')
-        self.modeButns.SetLabel(mode, True)
+        if not keep_mode:
+          self.modeButns.SetLabel(mode, True)
         self.ChangeBand(band)
         break
   def ChangeBand(self, band):

quisk_conf_defaults.py

@@ -1508,6 +1508,19 @@ remote_radio_ip = ""
 # It is only necessary to enter it once on each computer.
 remote_radio_password = ""
 
+## remote_radio_mic_jitter_ms         Mic buffer msec for remote radio, integer
+# This is set on the remote radio, not the control head.  The network can hold the control
+# head's microphone packets for 100 msec or more and then deliver them in a burst, which is
+# common over Wi-Fi.  The transmit audio then has gaps.  This buffers the microphone audio
+# for the given time before transmitting it, so the bursts are smoothed out, at the cost
+# of that much more transmit delay.  Zero turns the buffer off, which is best on a wired
+# network.  If needed, try 150 msec.  The maximum is 500.  A change takes effect when the
+# next control head connects.
+remote_radio_mic_jitter_ms = 0
+#remote_radio_mic_jitter_ms = 100
+#remote_radio_mic_jitter_ms = 150
+#remote_radio_mic_jitter_ms = 250
+
 ## k4_tcp_ip			IP address for K4 TCP, text
 # This is the Quisk IP address for the TCP server implementing K4 commands.
 k4_tcp_ip = ""