From 8073a9db25bb88943d75df508833a7aab958d1ee Mon Sep 17 00:00:00 2001
From: Kevin Le <vinhdat82@gmail.com>
Date: Thu, 17 Sep 2026 20:32:08 +0700
Subject: [PATCH] Fixed stm32 variants not compiling due to ltoa missing .
 https://github.com/meshcore-dev/MeshCore/pull/2655#issuecomment-5714564192

---
 platformio.ini                 | 1 +
 src/helpers/TxtDataHelpers.cpp | 9 ++++++++-
 2 files changed, 9 insertions(+), 1 deletion(-)

diff --git a/platformio.ini b/platformio.ini
index 28311ed7..87cf4557 100644
--- a/platformio.ini
+++ b/platformio.ini
@@ -133,6 +133,7 @@ build_flags = ${arduino_base.build_flags}
   -D STM32_PLATFORM
   -I src/helpers/stm32
   -I $PROJECT_PACKAGES_DIR/framework-arduinoststm32/libraries/SubGhz/src
+  -fpermissive
 build_src_filter = ${arduino_base.build_src_filter}
   +<helpers/stm32>
 lib_deps = ${arduino_base.lib_deps}
diff --git a/src/helpers/TxtDataHelpers.cpp b/src/helpers/TxtDataHelpers.cpp
index d327931f..05d72ab8 100644
--- a/src/helpers/TxtDataHelpers.cpp
+++ b/src/helpers/TxtDataHelpers.cpp
@@ -102,9 +102,16 @@ static void _ftoa(float f, char *p, int *status)
     *p++ = '0';
   else 
   {
-    ltoa(int_part, p, 10);
+    #if defined(STM32_PLATFORM)
+    int written = snprintf(p, 16, "%" PRId32, int_part);
+    if (written > 0) {
+      p += written;
+    }
+    #else
+    ltoa(int_part, p, 10); 
     while (*p)
       p++;
+    #endif
   }
   *p++ = '.';
   if (frac_part == 0)