From db34ed96e585aef04c50f92393319b0c3664d3df Mon Sep 17 00:00:00 2001
From: Markus Kirberg <markus@flobby.net>
Date: Mon, 10 Jun 2024 20:00:20 +0200
Subject: [PATCH] Check DHT Sensor values for errors (#1392)

* checkval

* bump to beta3

* fix and parenthesis
---
 mos.yml                       |  2 +-
 src/DHT/shelly_dht_sensor.cpp | 17 ++++++++++++++---
 2 files changed, 15 insertions(+), 4 deletions(-)

diff --git a/mos.yml b/mos.yml
index aa44a9a0..114a8867 100644
--- a/mos.yml
+++ b/mos.yml
@@ -1,6 +1,6 @@
 author: Shelly-HomeKit contributors
 description: A HomeKit firmware for Shelly switches
-version: 2.12.0-beta2
+version: 2.12.0-beta3
 
 libs_version: latest
 modules_version: latest
diff --git a/src/DHT/shelly_dht_sensor.cpp b/src/DHT/shelly_dht_sensor.cpp
index 7ac61b79..97bab0e3 100644
--- a/src/DHT/shelly_dht_sensor.cpp
+++ b/src/DHT/shelly_dht_sensor.cpp
@@ -83,9 +83,20 @@ StatusOr<float> DHTSensor::GetHumidity() {
 }
 
 void DHTSensor::UpdateTemperatureCB() {
-  // std::nan
-  result_ = mgos_dht_get_temp(dht);
-  result_humidity_ = mgos_dht_get_humidity(dht);
+  float result = mgos_dht_get_temp(dht);
+  float result_humidity = mgos_dht_get_humidity(dht);
+
+  // check values for validity
+  if (((result == 0) and (result_humidity == 0)) or isnan(result) or
+      isnan(result_humidity)) {
+    // error during readout do nothing for now
+    LOG(LL_INFO, ("DHT: invalid value received"));
+    return;
+  }
+
+  result_ = result;
+  result_humidity_ = result_humidity;
+
   if (notifier_) {
     notifier_();
   }