diff --git a/reflowctl/reflowctl.ino b/reflowctl/reflowctl.ino
index 3eb37a3..189d88a 100644
--- a/reflowctl/reflowctl.ino
+++ b/reflowctl/reflowctl.ino
@@ -19,7 +19,7 @@
 __attribute__((__unused__)) static unsigned int time = 0; // profile seconds
 __attribute__((__unused__)) static unsigned int temperatur = 25; // actual oven temp
 __attribute__((__unused__)) static unsigned int last_temperatur = 25; // last oven temp
-__attribute__((__unused__)) static int actual_dt = 0; // actual difference from last to actual temperatur
+__attribute__((__unused__)) static unsigned int actual_dt = 0; // actual difference from last to actual temperatur
 
 
 // profile temperatures
@@ -86,6 +86,7 @@ static void control_oven() {
   }
 }
 
+
 static void set_temp(int min, int max, int dt_min, int dt_max) {
   set_min = min;
   set_max = max;
@@ -93,12 +94,14 @@ static void set_temp(int min, int max, int dt_min, int dt_max) {
   set_dt_max = dt_max;
 }
 
+
 static void get_temp() {
   last_temperatur = temperatur;
   temperatur = int(float(analogRead(2)) * 0.2929);
   actual_dt = temperatur - last_temperatur;
 }
 
+
 static void check_dt() {
   if (actual_dt > set_dt_max) {
     error_condition |= E_DT_MAX;
@@ -142,42 +145,50 @@ static void set_start_state() {
   set_temp(Tp-5, Tp, 0, ramp_up_rate_max);
 }
 
+
 static void set_preheat_state() {
   Serial.println("Changing state to PREHEAT_STATE");
   state++;
 }
 
+
 static void set_ramp_up_state() {
   Serial.println("Changed state to RAMP_UP_STATE");
   state++;
 }
 
+
 static void set_tal_first_state() {
   Serial.println("Changed state to TAL_FIRST_STATE");
   state++;
 }
 
+
 static void set_peak_state() {
   Serial.println("Changed state to PEAK_STATE");
   state++;
 }
 
+
 static void set_tal_second_state() {
   Serial.println("Changed state to TAL_SECOND_STATE");
   set_temp(25, 25, -3, -6);
   state++;
 }
 
+
 static void set_ramp_down_state() {
   Serial.println("Changed state to RAMP_DOWN_STATE");
   state++;
 }
 
+
 static void set_end_state() {
   Serial.println("Changed state to END_STATE");
   state++;
 }
 
+
 void set_error_state() {
   if (state != ERROR_STATE) {
     Serial.println("Changed state to ERROR_STATE");
@@ -186,8 +197,8 @@ void set_error_state() {
   }
 }
 
+
 static void handle_start_state() {
-  Serial.println("START_STATE");
   if (temperatur > Ts_min) {
     Ts_min_time = time;
     set_preheat_state();
@@ -195,35 +206,31 @@ static void handle_start_state() {
 }
 
 
-
 static void handle_preheat_state() {
-  Serial.println("PREHEAT_STATE");
   if (temperatur > Ts_max) {
     Ts_max_time = time;
     set_ramp_up_state();
   }
 }
 
+
 static void handle_ramp_up_state() {
-  Serial.println("RAMP_UP_STATE");
   if (temperatur > Tl) {
     Tl_time_start = time;
     set_tal_first_state();
   }
 }
 
+
 static void handle_tal_first_state() {
-  Serial.println("TAL_FIRST_STATE");
   if (temperatur > Tp - 5) {
-    Serial.println("Changed state to PEAK_STATE");
     Tp_time_start = time;
     set_peak_state();
   }
 }
 
-static void handle_peak_state() {
-  Serial.println("PEAK_STATE");
 
+static void handle_peak_state() {
   if (time - Tp_time_start > Tp_duration) {
     Tp_time_end = time;
     set_tal_second_state();
@@ -239,12 +246,18 @@ static void handle_tal_second_state() {
 
 static void handle_ramp_down_state() {
   if (temperatur < Ts_min) {
-    Serial.println("Changed state to END_STATE");
     set_end_state();
   }
 }
 
 
+static void handle_end_state() {
+  while(true) {
+    continue;
+  }
+}
+
+
 static void handle_error_state() {
   if (led_on) {
     digitalWrite(13, LOW);
@@ -298,10 +311,7 @@ void loop() {
         handle_ramp_down_state();
         break;
       case END_STATE:
-        Serial.println("END_STATE");
-        while(true) {
-          continue;
-        }
+        handle_end_state();
         break;
       case ERROR_STATE:
         handle_error_state();