From c8cf8094c32a0de4ee11d0489e69b6e3d861c6b3 Mon Sep 17 00:00:00 2001
From: Ian McEwen <mian@cyverse.org>
Date: Fri, 23 Aug 2024 13:18:23 -0700
Subject: [PATCH] randomize packet IDs as firmware does

---
 meshtastic/mesh_interface.py | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/meshtastic/mesh_interface.py b/meshtastic/mesh_interface.py
index c83a399..6ee292e 100644
--- a/meshtastic/mesh_interface.py
+++ b/meshtastic/mesh_interface.py
@@ -802,7 +802,10 @@ class MeshInterface:  # pylint: disable=R0902
                 "Not connected yet, can not generate packet"
             )
         else:
-            self.currentPacketId = (self.currentPacketId + 1) & 0xFFFFFFFF
+            nextPacketId = (self.currentPacketId + 1) & 0xFFFFFFFF
+            nextPacketId = nextPacketId & (0xFFFFFFFF >> 22)             # mask upper 22 bits
+            randomPart = (random.randint(0, 0x7FFFFFFF) << 10) & 0xFFFFFFFF # generate number with 10 zeros at end
+            self.currentPacketId = nextPacketId | randomPart             # combine
             return self.currentPacketId
 
     def _disconnected(self):