diff --git a/firmware/20230512_firmware_dev.ino.bin b/firmware/20230512_firmware_dev.ino.bin
new file mode 100644
index 0000000..f22c2bd
Binary files /dev/null and b/firmware/20230512_firmware_dev.ino.bin differ
diff --git a/firmware/config.h b/firmware/config.h
index 172c4e2..725d32e 100644
--- a/firmware/config.h
+++ b/firmware/config.h
@@ -18,7 +18,7 @@
 #define EEPROM_LAST_STATE_ADDRESS              4 // the first "last state" information for the first light
 #define EEPROM_TIMING_DATA_ADDRESS             (EEPROM_LAST_STATE_ADDRESS + LIGHTS_COUNT) // Stored data date per light ELE_USED; HH; MM; CH1; CH2; CH3; CH4; 
 
-#define BRI_MOD_STEPS_PER_SEC                 10
+#define BRI_MOD_STEPS_PER_SEC                 25
 
 #define TIME_CHECK_INTERVAL_MS         (60000UL) // 60 second interval
 #define TIME_LIGHTENGINE_INTERVAL_MS    (1000UL / BRI_MOD_STEPS_PER_SEC) // BRI_MOD_STEPS_PER_SEC steps per second to in-/decrease the brightness
@@ -26,11 +26,11 @@
 #define MY_NTP_SERVER "de.pool.ntp.org"
 
 // 10 bit PWM
-#define PWM_FREQ    (50000UL)
+#define PWM_FREQ     (500UL)
 #define PWM_OFF             0 // 0V
 #define PWM_MIN             0 // 0V - minimum light amount (~1%)
 #define PWM_MAX           255 // 24V - maximum light amount (100%)
 #define BRI_TO_PWM_FACTOR 1.0 // 24V-0V = 24V range
 
 #define PWM_TEST_INTERVA_MS 1000
-#define TEST_PWM_CHG_CNT       5
+#define TEST_PWM_CHG_CNT       1
diff --git a/firmware/firmware.ino b/firmware/firmware.ino
index 3348974..eee9c23 100644
--- a/firmware/firmware.ino
+++ b/firmware/firmware.ino
@@ -162,7 +162,7 @@ void lightEngine()
       if (current_bri[i] != 0)
       {
         in_transition = true;
-        current_bri[i] += step_level[i] / BRI_MOD_STEPS_PER_SEC;
+        current_bri[i] -= step_level[i] / BRI_MOD_STEPS_PER_SEC;
         if (current_bri[i] < 0)
         {
           current_bri[i] = 0;
@@ -405,6 +405,13 @@ void init_webserver()
       {
         const char* key = state.key().c_str();
         int light = atoi(key) - 1;
+        if (light < 0)
+        {
+          light = 0;
+        } else if (light > (LIGHTS_COUNT-1))
+        {
+          light = (LIGHTS_COUNT-1);
+        }
         JsonObject values = state.value();
 
         uint8_t tmp = EEPROM.read(EEPROM_LAST_STATE_STARTUP_ADDRESS);
@@ -441,6 +448,10 @@ void init_webserver()
         if (values.containsKey("transitiontime"))
         {
           default_transitiontime = values["transitiontime"];
+          if (default_transitiontime < 0)
+          {
+            default_transitiontime = 0;
+          }
           if (tc_enabled == TIMING_CONTROL_DISABLED)
           {
             for (uint8_t i = 0 ; i < LIGHTS_COUNT; i++)
@@ -461,6 +472,13 @@ void init_webserver()
   server.on("/state", HTTP_GET, []()
   {  // HTTP GET request used to fetch current light state
     uint8_t light = server.arg("light").toInt() - 1;
+    if (light < 0)
+    {
+      light = 0;
+    } else if (light > (LIGHTS_COUNT-1))
+    {
+      light = (LIGHTS_COUNT-1);
+    }
     DynamicJsonDocument root(512);
     root["on"]     = light_state[light];
     root["bri"]    = bri[light];
@@ -536,6 +554,10 @@ void init_webserver()
     if (server.hasArg("transition"))
     {
       default_transitiontime = server.arg("transition").toFloat();
+      if (default_transitiontime < 0)
+      {
+        default_transitiontime = 0;
+      }
       if (tc_enabled == TIMING_CONTROL_DISABLED)
       {
         for (uint8_t i = 0 ; i < LIGHTS_COUNT; i++)
@@ -610,9 +632,11 @@ void init_webserver()
     }
 
     // scene switch handling
-    if (server.hasArg("scene")) {
+    if (server.hasArg("scene"))
+    {
       scene = server.arg("scene").toInt();
-      if (EEPROM.read(EEPROM_SCENE_ADDRESS) != scene) {
+      if (EEPROM.read(EEPROM_SCENE_ADDRESS) != scene)
+      {
         EEPROM.write(EEPROM_SCENE_ADDRESS, scene);
         EEPROM.commit();
         Serial.print("Scene set to ");
@@ -623,7 +647,8 @@ void init_webserver()
     if (server.hasArg("dip")) {
       uint8_t tmp = EEPROM.read(EEPROM_DYNAMIC_IP_ADDRESS);
       uint8_t tmp2 = (server.arg("dip") == "true" ? 1 : 0);
-      if (tmp != tmp2) {
+      if (tmp != tmp2)
+      {
         EEPROM.write(EEPROM_DYNAMIC_IP_ADDRESS, tmp2);
         EEPROM.commit();
         Serial.print("Set dynamic IP to ");
@@ -671,6 +696,7 @@ void init_webserver()
         } else if (server.arg("on" + (String)light) == "false" && light_state[light] == true)
         {
           light_state[light] = false;
+          bri[light] = 0;
           if (tmp == 0 && EEPROM.read(EEPROM_LAST_STATE_ADDRESS + light) == 1)
           {
             EEPROM.write(EEPROM_LAST_STATE_ADDRESS + light, LIGHT_STATE_OFF);