From 6d50391ea8a2568733af9053abbb0de2a04483ab Mon Sep 17 00:00:00 2001
From: MarekWo <mwojtaszek@gmail.com>
Date: Sun, 22 Feb 2026 13:45:43 +0100
Subject: [PATCH] fix: Decode GPS coordinates as int32/1e6, not float

MeshCore encodes lat/lon as little-endian signed int32 divided by 1e6,
not as IEEE 754 floats. This caused all map pins to show at (0,0).

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
---
 app/contacts_cache.py | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/app/contacts_cache.py b/app/contacts_cache.py
index d8b1ba7..cbd6e55 100644
--- a/app/contacts_cache.py
+++ b/app/contacts_cache.py
@@ -162,7 +162,7 @@ def parse_advert_payload(pkt_payload_hex: str):
       [32:36]  Timestamp (4 bytes)
       [36:100] Signature (64 bytes)
       [100]    App Flags (1 byte) - bit 4: Location, bit 7: Name
-      [101+]   If Location (bit 4): Lat (4 bytes) + Lon (4 bytes)
+      [101+]   If Location (bit 4): Lat (4 bytes, LE int32/1e6) + Lon (4 bytes, LE int32/1e6)
                If Name (bit 7): Node name (UTF-8, variable length)
 
     Returns:
@@ -184,7 +184,8 @@ def parse_advert_payload(pkt_payload_hex: str):
 
         if has_location:
             if len(raw) >= 109:
-                lat, lon = struct.unpack('<ff', raw[101:109])
+                lat_i, lon_i = struct.unpack('<ii', raw[101:109])
+                lat, lon = lat_i / 1e6, lon_i / 1e6
                 # Validate: discard NaN, Infinity, and out-of-range values
                 if (math.isnan(lat) or math.isnan(lon) or
                         math.isinf(lat) or math.isinf(lon) or