From 02f92bef2a1d051a099d303b44cea78c62b30a5f Mon Sep 17 00:00:00 2001
From: Thomas Hooge <thomas@hoogi.de>
Date: Sat, 21 Feb 2026 08:45:39 +0100
Subject: [PATCH] Started implementing message class, parsing rx and tx pgn
 list

---
 __init__.py |   1 +
 device.py   | 114 +++++++++++++++++++++++++++++++++++++++++++++++++---
 message.py  | 106 ++++++++++++++++++++++++++++++++++++++++++++++++
 parser.py   |  17 +++++++-
 4 files changed, 231 insertions(+), 7 deletions(-)
 create mode 100644 message.py

diff --git a/__init__.py b/__init__.py
index bd9905b..f145913 100644
--- a/__init__.py
+++ b/__init__.py
@@ -3,3 +3,4 @@ __version__ = "0.0.1"
 from .device import Device
 from .boatdata import BoatData
 from .hbuffer import History, HistoryBuffer
+from .message import Message
diff --git a/device.py b/device.py
index 443e7d3..7c191e5 100644
--- a/device.py
+++ b/device.py
@@ -12,6 +12,24 @@ import time
 import struct
 from . import lookup
 
+def set_to_lines(values, maxlen, indent=0):
+    spaces = ' ' * indent
+    lines = []
+    current = ""
+    for v in values:
+        part = str(v)
+        emax = maxlen - indent
+        if not current:
+            current = part
+        elif len(current) + 1 + len(part) <= emax:
+            current += ',' + part
+        else:
+            lines.append(spaces + current + ',')
+            current = part
+    if current:
+        lines.append(spaces + current)
+    return lines
+
 class Device():
 
     def __init__(self, address):
@@ -21,6 +39,7 @@ class Device():
         self.lastpinfo = None        # Wann letztes Mal Productinfo erhalten?
         self.lastcinfo = None        # Wann letztes Mal Configurationinfo erhalten?
         self.has_cinfo = True        # Weitere Abfragen können verhindert werden
+        self.has_pgnlist = False     # PGN-Listen Tx,Rx vorhanden
 
         # Device info
         self.NAME = 0                # Wird über getNAME (address claim) gefüllt, 64bit Integer
@@ -30,14 +49,13 @@ class Device():
         self.instlower = 0           # 3bit, ISO ECU Instance
         self.instupper = 0           # 5bit, ISO Function Instance
         self.sysinstance = 0         # used with bridged networks, default 0
-        self.industrygroup = None
         self.devicefunction = None
         self.deviceclass = None
 
         # Product info
-        self.product = None             # Product name
-        self.productcode = None         # Product code
-        self.serial = None
+        self.product = None             # Product name (ModelID)
+        self.productcode = None         # Product code (16bit unsigned)
+        self.serial = None              # Device serial number
         self.modelvers = None 		# Hardware Version
         self.softvers = None            # Current Software Version
         self.n2kvers = None             # NMEA2000 Network Message Database Version
@@ -47,7 +65,11 @@ class Device():
         # Configuration info
         self.instdesc1 = None
         self.instdesc2 = None
-        self.manufinfo = None 
+        self.manufinfo = None
+
+        # PGN lists, fill with functions defined below
+        self.pgns_transmit = set()
+        self.pgns_receive = set()
 
         # Additional data
         self.customname = None          # User defined device name
@@ -120,7 +142,7 @@ class Device():
                         print("Ignore collision because of our lower NAME")
                 else:
                     print(f"Answer: DEST={dest}")
-                    print(msg.data)
+                    print("Data:", msg.data)
                     if dest == self.address:
                         print("We are addressed: WIP!")
                     else:
@@ -133,6 +155,84 @@ class Device():
             print("claim seems ok after 250ms")
         return claim_ok
 
+    # TODO String handling
+    # Spec says ASCII is only 0x20 to 0x7E. But some devices use full
+    # Latin-1 / ISO-8859-1 code set.
+    # Unicode: 
+    #   UTF-16 Little Endian
+    #   UTF-8 eventually used in some PGNs?
+    def getStringFix(self, text, maxlength=32, filler=b' '):
+        if not text:
+            text = ''
+        if text.isascii():
+            # text.encode('latin1')
+            # text.encode('ascii') can throw errors
+            # text.encode('ascii', 'replace') sets question mark for unknown codes
+            #return b'x01' + bytes(text or '', 'ascii').ljust(maxlength, b' ')
+            return b'x01' + text.encode('ascii', 'ignore').ljust(maxlength, filler)
+        else:
+            # convert to UTF-16 Little Endian
+            return b'x00' + text.encode('utf-16-le').ljust(maxlength, filler)
+
+    def getProductInfo(self):
+        """
+        Returns data for msg prepared to be sent out as fast packet
+        """
+        print("Set Productinfo:", self.product)
+        data = bytearray()
+        data.extend(struct.pack('<H', self.n2kvers)) # 2 Byte
+        data.extend(struct.pack('<H', self.productcode)) # 2 Byte
+        data.append(0x01) # String
+        data.extend(bytes(self.product, 'latin1').ljust(32, b' '))
+        #data.extend(getStringFix(self.product))
+        data.append(0x01) # ASCII String
+        data.extend(bytes(self.softvers, 'latin1').ljust(32, b' '))
+        data.append(0x01)
+        data.extend(bytes(self.modelvers, 'latin1').ljust(32, b' '))
+        data.append(0x01)
+        data.extend(bytes(self.serial, 'latin1').ljust(32, b' '))
+        data.append(0x00) # Certification level
+        data.append(0x00) # Load equivalency 0=Not powered by bus
+        return data
+
+    def getConfigInfo(self):
+        """
+        Configuration info
+        """
+        print("Set Configinfo")
+        data = bytearray()
+        data.extend(self.getStringFix(self.instdesc1), 32)
+        data.extend(self.getStringFix(self.instdesc2), 32)
+        data.extend(self.getStringFix(self.manufinfo), 32)
+        #data.append(0x01) # ASCII String
+        #data.extend(bytes(self.instdesc1 or '', 'ascii').ljust(32, b' '))
+        #data.append(0x01)
+        #data.extend(bytes(self.instdesc2 or '', 'ascii').ljust(32, b' '))
+        #data.append(0x01)
+        #data.extend(bytes(self.manufinfo or '', 'ascii').ljust(32, b' '))
+        return data
+
+    """
+    PGN lists (mandatory)
+      59904 ISO Request
+      60928 ISO Address Claim
+      126208 Group Function (Request / Command / Acknowledge)
+      126464 PGN List (Transmit / Receive)
+      126993 Heartbeat
+      126996 Product Information
+      126998 Configuration Information
+    """
+    def setTxPGNs(self, pgnlist, mandatory=True):
+        self.pgns_transmit = set(pgnlist)
+        if mandatory:
+            self.pgns_transmit.add((60928, 126208, 126464, 126996))
+
+    def setRxPGNs(self, pgnlist, mandatory=True):
+        self.pgns_receive = set(pgnlist)
+        if mandatory:
+            self.pgns_receive.add((59904, 60928, 126208, 126996, 126998))
+
+
     def __str__(self):
         out =  f"Device: {self.address} : '{self.product}'\n"
         out +=  "  NAME: {} ({})\n".format(self.getNAME(), self.NAME)
@@ -177,4 +277,6 @@ class Device():
             out += f"    Manufacturer info: {self.manufinfo}\n"
         else:
             out += "    not available\n"
+        out += "  PGNs RX: \n{}\n".format('\n'.join(set_to_lines(self.pgns_receive, 72, 4)) or 'n/a')
+        out += "  PGNs TX: \n{}\n".format('\n'.join(set_to_lines(self.pgns_transmit, 72, 4)) or 'n/a')
         return out
diff --git a/message.py b/message.py
new file mode 100644
index 0000000..9eff93d
--- /dev/null
+++ b/message.py
@@ -0,0 +1,106 @@
+"""
+NMEA2000 Nachricht
+
+"""
+
+import can
+import struct
+from math import ceil
+from .pgntype import pgntype
+
+class Message():
+
+    def __init__(self, bus, source, data=None):
+        self._bus = bus
+        self._source = source
+        self._priority = 5
+        if data:
+            print("msg: set data: ", type(data))
+            self._data = data
+        else:
+            self._data = bytearray()
+        self.pgn = None
+        #self.sequence = 0xff
+        self.sequence = 0
+
+    def set_pgn(self, pgn):
+        self.pgn = pgn
+
+    def set_priority(self, priority):
+        self._priority = priority
+
+    def get_fast_frames(self, rawdata, sc):
+        # Erstelle ein Liste von Frames aufgrund vorliegender Rohdaten
+        # zum transferieren von bis zu 223 Bytes über eine fast-Message
+        # Der sequence-counter muß extern inkrementiert werden, er hat
+        # 3 Bit Länge. Der Framecounter fc hat eine Länge von 5 Bit.
+        # Der erste Frame kann 6 Bytes aufnehmen
+        # Alle weiteren Frames jeweils 7 Bytes
+        datalen = len(rawdata)
+        if datalen > 223:
+            raise ValueError("data for fast packet too long")
+        if datalen < 7:
+            raise ValueError("data for fast packet too short")
+        nf = ceil((datalen - 6) / 7 + 1) # number of frames
+        fc = 0                           # frame counter, nibble 2
+        frames = list()
+        # Frame 1
+        data = bytearray()
+        data.append((sc << 5) + fc)
+        data.append(datalen)
+        for b in rawdata[:6]:
+            data.append(b)
+        frames.append(data)
+        nf -= 1
+        # Frame 2..n
+        p = 6
+        while nf > 0:
+            data = bytearray()
+            fc += 1
+            data.append((sc << 5) + fc)
+            for b in rawdata[p:p+7]:
+                data.append(b)
+            frames.append(data)
+            p += 7
+            nf -= 1
+        print("message:get_fast_frames")
+        print(frames)
+        return frames
+
+    def send_single(self):
+        msg = can.Message(
+            arbitration_id = (((self._priority << 18) + self.pgn) << 8) + self._source,
+            data = self._data,
+            is_extended_id = True
+        );
+        try:
+            self._bus.send(msg)
+        except can.CanError:
+            print(f"Message {self.pgn} NOT sent")
+            return False
+        return True
+
+    def send_fast(self):
+        id = (((self._priority << 18) + self.pgn) << 8) + self._source
+        try:
+            for frame in self.get_fast_frames(self._data, self.sequence):
+                msg = can.Message(
+                    arbitration_id = id,
+                    data = frame,
+                    is_extended_id = True
+                );
+                self._bus.send(msg)
+        except can.CanError:
+            print(f"Message {self.pgn} NOT sent")
+            return False
+        finally:
+            self.sequence += 1
+            self.sequence %= 8
+            print("send fast: adjusted sequence {}".format(self.sequence))
+        return True
+
+    def send(self):
+       if pgntype(self.pgn) == "S":
+           self.send_single()
+       else:
+           self.send_fast()
diff --git a/parser.py b/parser.py
index d7ba736..06be9d8 100644
--- a/parser.py
+++ b/parser.py
@@ -26,6 +26,22 @@ def parse_60928(buf, device):
     device.sysinstance = buf[7] & 0x0f           # 4bit
     return struct.unpack_from('>Q', buf, 0)[0]
 
+def parse_126464(buf, device):
+    # PGN Lists: tx and rx
+    # Byte 1: 0 = Transmit PGN list
+    #         1 = Receive PGN list
+    functioncode = buf[0]
+    # set of 24bit PGNs (little endian)
+    values = { buf[i] | (buf[i+1] << 8) | (buf[i+2] << 16)
+               for i in range(1, len(buf)-4, 3) }
+    if functioncode == 0:
+        device.pgns_transmit = values
+    elif functioncode == 1:
+        device.pgns_receive = values
+    else:
+        return
+    device.has_pgnlist = True
+
 def parse_126983(buf, source):
     # Alert
     # PGN 126984 is response
@@ -93,7 +109,6 @@ def parse_126992(buf, source):
 def parse_126993(buf, device):
     # Heartbeat
     print(f"Heartbeat from {device.address}")
-    print(buf)
 
 def parse_126996(buf, device):
     # Product information