diff --git a/src/Sensors/DistanceSensor.cpp b/src/Sensors/DistanceSensor.cpp
index be2d732..979c63f 100644
--- a/src/Sensors/DistanceSensor.cpp
+++ b/src/Sensors/DistanceSensor.cpp
@@ -10,6 +10,7 @@ namespace Dough
 
     DistanceSensor::DistanceSensor() : _logger("DISTANCE")
     {
+        _logger.log("s", "INIT distance sensor object");// TODO
         _hcsr04 = new SensorHCSR04(HCSR04_TRIG_PIN, HCSR04_ECHO_PIN);
     }
 
diff --git a/src/Sensors/LowLevel/SensorDHT11.cpp b/src/Sensors/LowLevel/SensorDHT11.cpp
index b2c1418..87625ff 100644
--- a/src/Sensors/LowLevel/SensorDHT11.cpp
+++ b/src/Sensors/LowLevel/SensorDHT11.cpp
@@ -2,10 +2,6 @@
 
 namespace Dough
 {
-    // ----------------------------------------------------------------------
-    // Constructor
-    // ----------------------------------------------------------------------
-
     // I am using a singleton here, to make it possible to use the physical
     // DHT11 sensor from the two logical sensors TemperatureSensor and
     // HumiditySensor.
@@ -20,19 +16,16 @@ namespace Dough
         _dht = new DHT(DHT11_DATA_PIN, DHT11);
     }
 
-    // ----------------------------------------------------------------------
-    // setup
-    // ----------------------------------------------------------------------
-
     void SensorDHT11::begin()
     {
-        _dht->begin();
+        static bool begun = false;
+        if (!begun)
+        {
+            begun = true;
+            _dht->begin();
+        }
     }
 
-    // ----------------------------------------------------------------------
-    // loop
-    // ----------------------------------------------------------------------
-
     float SensorDHT11::readHumidity()
     {
         return _dht->readHumidity();
@@ -42,4 +35,4 @@ namespace Dough
     {
         return _dht->readTemperature();
     }
-}
\ No newline at end of file
+} // namespace Dough
\ No newline at end of file
diff --git a/src/Sensors/LowLevel/SensorHCSR04.cpp b/src/Sensors/LowLevel/SensorHCSR04.cpp
index ed58f59..f7e02d8 100644
--- a/src/Sensors/LowLevel/SensorHCSR04.cpp
+++ b/src/Sensors/LowLevel/SensorHCSR04.cpp
@@ -64,7 +64,7 @@ namespace Dough
     void SensorHCSR04::_setEchoTimeout()
     {
         _echoTimeout = HCSR04_MAX_MM * 2 / _speedOfSound;
-        _logger.log("sfs", "Echo timeout = ", _echoTimeout, "Ms");
+        _logger.log("sis", "Echo timeout = ", _echoTimeout, "Ms");
     }
 
     void SensorHCSR04::_takeSamples()
diff --git a/src/Sensors/LowLevel/SensorHCSR04.h b/src/Sensors/LowLevel/SensorHCSR04.h
index d3683f4..396b70f 100644
--- a/src/Sensors/LowLevel/SensorHCSR04.h
+++ b/src/Sensors/LowLevel/SensorHCSR04.h
@@ -54,7 +54,7 @@ namespace Dough
         void _setSpeedOfSound();
         float _speedOfSound;
         void _setEchoTimeout();
-        int _echoTimeout;
+        unsigned int _echoTimeout;
         float _samples[HCSR04_SAMPLES_TAKE];
         void _takeSamples();
         bool _haveEnoughSamples();
diff --git a/src/UI/UI.cpp b/src/UI/UI.cpp
index c75fe1b..7ae62e8 100644
--- a/src/UI/UI.cpp
+++ b/src/UI/UI.cpp
@@ -2,10 +2,6 @@
 
 namespace Dough
 {
-    // ----------------------------------------------------------------------
-    // Constructor
-    // ----------------------------------------------------------------------
-
     UI *UI::_instance = nullptr;
 
     UI *UI::Instance()
@@ -24,10 +20,6 @@ namespace Dough
                led2(LED2_PIN),
                led3(LED3_PIN) {}
 
-    // ----------------------------------------------------------------------
-    // Setup
-    // ----------------------------------------------------------------------
-
     void UI::setup()
     {
         // Setup the buttons.
@@ -99,10 +91,6 @@ namespace Dough
             ; // Wait for synchronization
     }
 
-    // ----------------------------------------------------------------------
-    // Loop
-    // ----------------------------------------------------------------------
-
     // Disables the TC4 interrupts, suspending timed async updates to
     // the user interface.
     void UI::suspend()