From 399cc3f267af02193ed4a89037436be507931903 Mon Sep 17 00:00:00 2001
From: Marat Fayzullin <luarvique@gmail.com>
Date: Tue, 12 Nov 2024 21:44:30 -0500
Subject: [PATCH] Adding CW skimmer.

---
 csdr/chain/toolbox.py  | 25 +++++++++++++++++++++++--
 csdr/module/toolbox.py |  6 ++++++
 owrx/dsp.py            |  3 +++
 owrx/modes.py          |  1 +
 owrx/toolbox.py        | 34 ++++++++++++++++++++++++++++++++++
 5 files changed, 67 insertions(+), 2 deletions(-)

diff --git a/csdr/chain/toolbox.py b/csdr/chain/toolbox.py
index 0868d2a7..0e736614 100644
--- a/csdr/chain/toolbox.py
+++ b/csdr/chain/toolbox.py
@@ -1,8 +1,8 @@
 from csdr.chain.demodulator import ServiceDemodulator, DialFrequencyReceiver
-from csdr.module.toolbox import Rtl433Module, MultimonModule, DumpHfdlModule, DumpVdl2Module, Dump1090Module, AcarsDecModule, RedseaModule, SatDumpModule
+from csdr.module.toolbox import Rtl433Module, MultimonModule, DumpHfdlModule, DumpVdl2Module, Dump1090Module, AcarsDecModule, RedseaModule, SatDumpModule, CwSkimmerModule
 from pycsdr.modules import FmDemod, AudioResampler, Convert, Agc, Squelch
 from pycsdr.types import Format
-from owrx.toolbox import TextParser, PageParser, SelCallParser, EasParser, IsmParser, RdsParser
+from owrx.toolbox import TextParser, PageParser, SelCallParser, EasParser, IsmParser, RdsParser, CwSkimmerParser
 from owrx.aircraft import HfdlParser, Vdl2Parser, AdsbParser, AcarsParser
 
 from datetime import datetime
@@ -223,6 +223,27 @@ class RdsDemodulator(ServiceDemodulator, DialFrequencyReceiver):
         self.parser.setDialFrequency(frequency)
 
 
+class CwSkimmerDemodulator(ServiceDemodulator, DialFrequencyReceiver):
+    def __init__(self, sampleRate: int = 12000, charCount: int = 8):
+        self.sampleRate = sampleRate
+        self.parser = CwSkimmerParser()
+        workers = [
+            CwSkimmerModule(sampleRate, charCount),
+            self.parser,
+        ]
+        # Connect all the workers
+        super().__init__(workers)
+
+    def getFixedAudioRate(self) -> int:
+        return self.sampleRate
+
+    def supportsSquelch(self) -> bool:
+        return False
+
+    def setDialFrequency(self, frequency: int) -> None:
+        self.parser.setDialFrequency(frequency)
+
+
 class NoaaAptDemodulator(ServiceDemodulator):
     def __init__(self, satellite: int = 19, service: bool = False):
         d = datetime.utcnow()
diff --git a/csdr/module/toolbox.py b/csdr/module/toolbox.py
index 2308a40f..3ca568ed 100644
--- a/csdr/module/toolbox.py
+++ b/csdr/module/toolbox.py
@@ -119,6 +119,12 @@ class AcarsDecModule(WavFileModule):
         return Format.CHAR
 
 
+class CwSkimmerModule(ExecModule):
+    def __init__(self, sampleRate: int = 12000, charCount: int = 8):
+        cmd = ["csdr-cwskimmer", "-r", str(sampleRate), "-n", str(charCount)]
+        super().__init__(Format.FLOAT, Format.CHAR, cmd)
+
+
 class RedseaModule(ExecModule):
     def __init__(self, sampleRate: int = 171000, rbds: bool = False):
         cmd = [ "redsea", "--input", "mpx", "--samplerate", str(sampleRate) ]
diff --git a/owrx/dsp.py b/owrx/dsp.py
index 72167b0a..aa922365 100644
--- a/owrx/dsp.py
+++ b/owrx/dsp.py
@@ -720,6 +720,9 @@ class DspManager(SdrSourceEventClient, ClientDemodulatorSecondaryDspEventClient)
         elif mod == "cwdecoder":
             from csdr.chain.digimodes import CwDemodulator
             return CwDemodulator(75.0)
+        elif mod == "cwskimmer":
+            from csdr.chain.digimodes import CwSkimmerDemodulator
+            return CwSkimmerDemodulator()
         elif mod == "mfrtty170":
             from csdr.chain.digimodes import MFRttyDemodulator
             return MFRttyDemodulator(170.0, 45.45, reverse = False)
diff --git a/owrx/modes.py b/owrx/modes.py
index c34b8aaa..21d804c3 100644
--- a/owrx/modes.py
+++ b/owrx/modes.py
@@ -194,6 +194,7 @@ class Modes(object):
             squelch=False,
         ),
         DigitalMode("cwdecoder", "CW Decoder", underlying=["usb", "lsb"]),
+        DigitalMode("cwskimmer", "CW Skimmer", underlying=["usb", "lsb"]),
 # Replaced by Jakob's RTTY decoder
 #        DigitalMode("mfrtty170", "RTTY-170", underlying=["usb"]),
 #        DigitalMode("mfrtty450", "RTTY-450", underlying=["usb"]),
diff --git a/owrx/toolbox.py b/owrx/toolbox.py
index 06f4e366..140da2d3 100644
--- a/owrx/toolbox.py
+++ b/owrx/toolbox.py
@@ -414,3 +414,37 @@ class EasParser(TextParser):
 
         # Return received message as text
         return "\n".join(out)
+
+
+class CwSkimmerParser(TextParser):
+    def __init__(self, charTotal: int = 32, service: bool = False):
+        self.reLine = re.compile("^(\d+):\s*(.*)$")
+        self.data = {}
+        # Construct parent object
+        super().__init__(filePrefix="CW", service=service)
+
+    def parse(self, msg: bytes):
+        # Do not parse in service mode
+        if self.service:
+            return None
+        # Parse CW messages by frequency
+        msg = msg.decode("utf-8", "replace")
+        r = self.reLine.match(msg)
+        if r is not None:
+            freq = int(r.group(1))
+            text = r.group(2)
+            # Add up newly decoded characters
+            if freq in self.data:
+                text = self.data[freq] + text
+            # Truncate received text to charTotal
+            text = text if len(text) <= charTotal else text[:charTotal]
+            self.data[freq] = text
+            # Compose output
+            out = { "mode": "CW", "text": text }
+            # Add frequency, if known
+            if self.frequency:
+                out["freq"] = self.frequency + freq
+            # Done
+            return out
+        # No result
+        return None