From c120744e8e89bff0ddc9785c4a19928b42163330 Mon Sep 17 00:00:00 2001
From: Hector van der Aa <hector@h3cx.dev>
Date: Sun, 17 May 2026 14:40:55 +0200
Subject: [PATCH] Added Packet3 for Lap completion

---
 cpp/telemetry_common.h     |  9 +++++++++
 python/telemetry_common.py | 24 +++++++++++++++++++++---
 2 files changed, 30 insertions(+), 3 deletions(-)

diff --git a/cpp/telemetry_common.h b/cpp/telemetry_common.h
index 6bd0295..5acdc98 100644
--- a/cpp/telemetry_common.h
+++ b/cpp/telemetry_common.h
@@ -2,6 +2,7 @@
 // Copyright (C) 2026 Association Exergie <association.exergie@gmail.com>
 // SPDX-License-Identifier: MIT
 #pragma once
+#include <cstdint>
 #include <inttypes.h>
 
 #pragma pack(push, 1)
@@ -21,6 +22,14 @@ struct TelemetryPacket2 {
 };
 #pragma pack(pop)
 
+#pragma pack(push, 1)
+struct TelemetryPacket3 {
+  uint32_t start_time_;
+  uint32_t duration_;
+  uint16_t count_;
+};
+#pragma pack(pop)
+
 #pragma pack(push, 1)
 struct TelemetryLoRaHeader {
   uint8_t source_;
diff --git a/python/telemetry_common.py b/python/telemetry_common.py
index 577dbbc..3faec2c 100644
--- a/python/telemetry_common.py
+++ b/python/telemetry_common.py
@@ -4,17 +4,19 @@
 import struct
 from dataclasses import dataclass
 
-UART_MAGIC = b"\xAA\x55\xAA\x55"
+UART_MAGIC = b"\xaa\x55\xaa\x55"
 
 LORA_HEADER_FORMAT = "<BBBBH"
 UART_HEADER_FORMAT = "<4sB"
 PACKET1_FORMAT = "<4s"
 PACKET2_FORMAT = "<Ifffff"
+PACKET3_FORMAT = "<IIH"
 
 LORA_HEADER_SIZE = struct.calcsize(LORA_HEADER_FORMAT)
 UART_HEADER_SIZE = struct.calcsize(UART_HEADER_FORMAT)
 PACKET1_SIZE = struct.calcsize(PACKET1_FORMAT)
 PACKET2_SIZE = struct.calcsize(PACKET2_FORMAT)
+PACKET3_SIZE = struct.calcsize(PACKET3_FORMAT)
 
 
 @dataclass
@@ -41,6 +43,13 @@ class TelemetryPacket2:
     speed: float
 
 
+@dataclass
+class TelemetryPacket3:
+    start_time: int
+    duration: int
+    count: int
+
+
 def crc16_ccitt(data: bytes) -> int:
     crc = 0xFFFF
     for byte in data:
@@ -54,7 +63,9 @@ def crc16_ccitt(data: bytes) -> int:
 
 
 def unpack_lora_header(data: bytes) -> TelemetryLoRaHeader:
-    source, dest, version, size, crc16 = struct.unpack(LORA_HEADER_FORMAT, data[:LORA_HEADER_SIZE])
+    source, dest, version, size, crc16 = struct.unpack(
+        LORA_HEADER_FORMAT, data[:LORA_HEADER_SIZE]
+    )
     return TelemetryLoRaHeader(source, dest, version, size, crc16)
 
 
@@ -64,5 +75,12 @@ def unpack_packet1(payload: bytes) -> TelemetryPacket1:
 
 
 def unpack_packet2(payload: bytes) -> TelemetryPacket2:
-    time_stamp, vbat, teng, lat, lng, speed = struct.unpack(PACKET2_FORMAT, payload[:PACKET2_SIZE])
+    time_stamp, vbat, teng, lat, lng, speed = struct.unpack(
+        PACKET2_FORMAT, payload[:PACKET2_SIZE]
+    )
     return TelemetryPacket2(time_stamp, vbat, teng, lat, lng, speed)
+
+
+def unpack_packet3(payload: bytes) -> TelemetryPacket3:
+    start_time, duration = struct.unpack(PACKET3_FORMAT, payload[:PACKET3_SIZE])
+    return TelemetryPacket2(start_time, duration)