From b5cd671ed429d8eeaeacc1765666b984de9809ad Mon Sep 17 00:00:00 2001
From: Jens Ahrensfeld <jens@jayfield.org>
Date: Mon, 16 Mar 2026 17:00:11 +0100
Subject: [PATCH] - UBX: fixed data loss when sync byte in payload - refactored

---
 network_backend.py         |  4 +++-
 receiver/ubx_packetizer.py | 11 ++++++++---
 receiver/ubx_receiver.py   |  2 +-
 3 files changed, 12 insertions(+), 5 deletions(-)

diff --git a/network_backend.py b/network_backend.py
index 9bc8075..a36d9da 100644
--- a/network_backend.py
+++ b/network_backend.py
@@ -104,7 +104,9 @@ if __name__ == "__main__":
 			Gga(grm, 'GN'),
 		]
 		ubx_rx_list = [
-			UbxReceiver(grm, 0x01, 0x43),
+			UbxReceiver('UBX-NAV-SIG', 0x01, 0x43),
+			UbxReceiver('UBX-ACK-ACK', 0x05, 0x01),
+			UbxReceiver('UBX-ACK-NACK', 0x05, 0x00),
 		]
 
 		# Topology
diff --git a/receiver/ubx_packetizer.py b/receiver/ubx_packetizer.py
index d02111e..cd71277 100644
--- a/receiver/ubx_packetizer.py
+++ b/receiver/ubx_packetizer.py
@@ -13,6 +13,8 @@ class UbxPacketizer(MsgSink, MsgSource):
 		self.packet = b''
 		self.wait_sync = True
 		self.sync_count = 0
+		self.timestamp = 0
+		self.d_save = b''
 
 	def reset(self):
 		self.packet = b''
@@ -20,24 +22,27 @@ class UbxPacketizer(MsgSink, MsgSource):
 		self.sync_count = 0
 
 	def on_recv(self, msg: MsgContainer):
-		name = msg.name
-		timestamp = msg.timestamp
 		for n in range (0, len(msg.data)):
 			d = msg.data[n]
 			if d == self.sync_bytes[self.sync_count]:
+				self.d_save = struct.pack('B', d)
 				self.sync_count += 1
 				if self.sync_count == len(self.sync_bytes):
 					print("UBX-sync")
+					self.d_save = b''
+					self.timestamp = msg.timestamp
 					self.sync_count = 0
 					self.packet = b''
 					self.wait_sync = False
 			else:
+				self.packet += self.d_save
+				self.d_save = b''
 				if not self.wait_sync:
 					self.packet += struct.pack('B', d)
 					data, hdr = frame_parse(self.packet)
 					if data is not None:
 						if hdr.length == len(data):
-							self.call_sinks(MsgContainer(name, timestamp, self.packet))
+							self.call_sinks(MsgContainer(msg.name, self.timestamp, self.packet))
 							self.packet = b''
 
 
diff --git a/receiver/ubx_receiver.py b/receiver/ubx_receiver.py
index ad1baf4..aea8171 100644
--- a/receiver/ubx_receiver.py
+++ b/receiver/ubx_receiver.py
@@ -11,7 +11,7 @@ class UbxReceiver(MsgSink):
 
 	def on_recv(self, msg: MsgContainer):
 		data, hdr = frame_parse(msg.data)
-		print(f"{hdr.mclass}:{hdr.mid}:{data}")
+		print(f"{msg.name}:{self.name}:{hdr.mclass}:{hdr.mid}:data({len(data)}):{data}")
 
 	def is_msg(self, msg: MsgContainer):
 		hdr = frame_parse_hdr(msg.data)