From f31159b430998a5bed4e7a65e7bcdcff29cdc196 Mon Sep 17 00:00:00 2001
From: jpirnay <jens@pirnay.com>
Date: Fri, 17 Apr 2026 23:32:26 +0200
Subject: [PATCH] Temperature sanity check

---
 lib/hal/HalClock.cpp | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/lib/hal/HalClock.cpp b/lib/hal/HalClock.cpp
index 30c7bd8c..fdd1ca4a 100644
--- a/lib/hal/HalClock.cpp
+++ b/lib/hal/HalClock.cpp
@@ -281,8 +281,14 @@ static time_t readExternalRTC() {
 static float readExternalTemp() {
   Wire.beginTransmission(DS3231_ADDRESS);
   Wire.write(0x11);
-  Wire.endTransmission();
-  Wire.requestFrom(DS3231_ADDRESS, (uint8_t)2);
+  if (Wire.endTransmission() != 0) {
+    return 0.0f;
+  }
+
+  int count = Wire.requestFrom(DS3231_ADDRESS, (uint8_t)2);
+  if (count < 2) {
+    return 0.0f;
+  }
 
   int8_t msb = Wire.read();
   uint8_t lsb = Wire.read();