diff --git a/src/WSLed.cpp b/src/WSLed.cpp
index 7ca0fba..c386bcf 100644
--- a/src/WSLed.cpp
+++ b/src/WSLed.cpp
@@ -1,6 +1,7 @@
 // Ovladani signalizacni chytre LED diody
 #include "WSLed.hpp"
 #include <ACPU.hpp>
+#include <cmath>
 #if defined(ARDUINO_ARCH_ESP32)
     // # include "esp_task.h"
     //  https://github.com/JSchaenzle/ESP32-NeoPixel-WS2812-RMT/blob/master/ws2812_control.c
@@ -31,20 +32,12 @@ static const uint16_t LB[] ACPU_PROGMEM = {
     0x1c4, 0x1bd, 0x1b6, 0x1af, 0x1a7, 0x1a0, 0x198, 0x191, 0x18a, 0x182, 0x17b, 0x174, 0x16d, 0x167, 0x161, 0x15a, 0x154, 0x14f, 0x149, 0x144, 0x13f, 0x13a, 0x136, 0x131,
     0x12d, 0x12a, 0x126, 0x123, 0x11f, 0x11c, 0x11a, 0x117, 0x115, 0x112, 0x110, 0x10e, 0x10c, 0x10b, 0x109, 0x108, 0x107, 0x105, 0x104, 0x203, 0x102, 0x201, 0x2900};
 
-static void ledTrampoline(wsLED * ptr)
-{
-
-    ptr->rtLed();
-}
-
-inline bool wsLED::canShow() const
-{
+inline bool wsLED::canShow() const {
 
     return (micros() - mEndTime) >= 70L;
 }
 
-void wsLED::show()
-{
+void wsLED::show() {
     uint8_t color[3];
 
     for (uint8_t i = 0; i < 3; i++) {
@@ -52,8 +45,13 @@ void wsLED::show()
         uint16_t c = (uint16_t) mColor[i] * (1 + (uint16_t) mScale);
         color[i] = (uint8_t) (c >> 8);
     }
-    while (!canShow())
+    if (memcmp(color, mPrevColor, 3) == 0) {
+        return; // no change
+    }
+    memcpy(mPrevColor, color, 3);
+    while (!canShow()) {
         __asm__ volatile("nop");
+    }
 #if defined(ARDUINO_ARCH_ESP32)
     uint32_t bits_to_send = ((uint32_t) color[0] << 16) | ((uint32_t) color[1] << 8) | (uint32_t) color[2];
     uint32_t mask = 1 << (BITS_PER_LED_CMD - 1);
@@ -78,13 +76,11 @@ void wsLED::show()
 }
 
 wsLED::wsLED(int pin, int order)
-    : mPin(pin), mOrder(order)
-{
+    : mPin(pin), mOrder(order) {
 }
 
 wsLED::wsLED()
-    : mPin(NOT_A_PIN), mOrder(RGB)
-{
+    : mPin(NOT_A_PIN), mOrder(RGB) {
 }
 
 void wsLED::begin(int pin)
@@ -94,8 +90,7 @@ void wsLED::begin(int pin)
     begin();
 }
 
-void wsLED::begin()
-{
+void wsLED::begin() {
 
     if (NOT_A_PIN != mPin) {
 #if defined(ARDUINO_ARCH_ESP8266)
@@ -122,16 +117,14 @@ void wsLED::begin()
     }
 }
 
-void wsLED::setColor(const LEDRGB & color)
-{
+void wsLED::setColor(const LEDRGB & color) {
 
     mColor[(mOrder >> 6) & 7] = color.r;
     mColor[(mOrder >> 3) & 7] = color.g;
     mColor[mOrder & 7] = color.b;
 }
 
-void wsLED::rtLed()
-{
+void wsLED::rtLed() {
     uint32_t timing;
 
     mTimer.detach();
@@ -178,11 +171,10 @@ void wsLED::rtLed()
             break;
     }
     show();
-    mTimer.attach_ms(timing, ledTrampoline, this);
+    mTimer.attach_ms(timing, wsLED::ledTrampoline, this);
 }
 
-void wsLED::setColors(const LEDRGB & color1, const LEDRGB & color2)
-{
+void wsLED::setColors(const LEDRGB & color1, const LEDRGB & color2) {
 
     mColor1 = color1;
     mColor2 = color2;
@@ -191,8 +183,7 @@ void wsLED::setColors(const LEDRGB & color1, const LEDRGB & color2)
     }
 }
 
-void wsLED::blink(uint32_t speed)
-{
+void wsLED::blink(uint32_t speed) {
 
     if (NOT_A_PIN != mPin) {
         if (LED_BLINK != mLedState) {
@@ -201,13 +192,12 @@ void wsLED::blink(uint32_t speed)
             mScale = 0xff;
             mSubState = 1;
             mBlinkSpeed = speed;
-            mTimer.attach_ms(5, ledTrampoline, this);
+            mTimer.attach_ms(5, wsLED::ledTrampoline, this);
         }
     }
 }
 
-void wsLED::breath()
-{
+void wsLED::breath() {
 
     if (NOT_A_PIN != mPin) {
         if (LED_BREATH != mLedState) {
@@ -215,19 +205,17 @@ void wsLED::breath()
             mLedState = LED_BREATH;
             mSubState = 0;
             setColor(mColor1);
-            mTimer.attach_ms(5, ledTrampoline, this);
+            mTimer.attach_ms(5, wsLED::ledTrampoline, this);
         }
     }
 }
 
-void wsLED::setOrder(int neworder)
-{
+void wsLED::setOrder(int neworder) {
 
     mOrder = neworder;
 }
 
-void wsLED::pulse(const LEDRGB & color, uint32_t duration)
-{
+void wsLED::pulse(const LEDRGB & color, uint32_t duration) {
 
     if (NOT_A_PIN != mPin) {
         mTimer.detach();
@@ -240,18 +228,16 @@ void wsLED::pulse(const LEDRGB & color, uint32_t duration)
         }
         mPulseDuration = duration;
         mLedState = LED_PULSE_START;
-        mTimer.attach_ms(5, ledTrampoline, this);
+        mTimer.attach_ms(5, wsLED::ledTrampoline, this);
     }
 }
 
-ledstate_t wsLED::getState()
-{
+ledstate_t wsLED::getState() {
 
     return mLedState;
 }
 
-void wsLED::stop(const LEDRGB & color)
-{
+void wsLED::stop(const LEDRGB & color) {
 
     if (NOT_A_PIN != mPin) {
         mTimer.detach();
diff --git a/src/WSLed.hpp b/src/WSLed.hpp
index b4f7dfb..4d6abb8 100644
--- a/src/WSLed.hpp
+++ b/src/WSLed.hpp
@@ -136,7 +136,7 @@ class wsLED {
     Ticker mTimer;
     volatile ledstate_t mLedState = LED_STOP; // stav LEDky (blika, dycha, ...)
     volatile ledstate_t mSavedState = LED_STOP; // stav pro navrat
-    volatile int mSubState = 0; // pomocny stav/index v poli dychani
+    volatile unsigned mSubState = 0; // pomocny stav/index v poli dychani
     uint32_t mPulseDuration = 0;
     uint32_t mBlinkSpeed = 0;
     LEDRGB mPulseColor;
@@ -145,17 +145,24 @@ class wsLED {
     rmt_item32_t led_data_buffer[LED_BUFFER_ITEMS] = {0};
 #endif
     uint32_t mEndTime = 0;
+    uint8_t mPrevColor[3] = {1, 2, 3}; // some not used colors
 
     void show();
     void setColor(const LEDRGB & color);
     [[nodiscard]] bool canShow() const;
 
+    void rtLed(); // vykonna metoda
+
+    static void ledTrampoline(wsLED * ptr) {
+
+        ptr->rtLed();
+    }
+
   public:
-    wsLED(int pin, int order = RGB);
+    explicit wsLED(int pin, int order = RGB);
     wsLED();
     void begin();
     void begin(int pin);
-    void rtLed(); // vykonna metoda
     void setColors(const LEDRGB & color1, const LEDRGB & color2 = LEDRGB(0, 0, 0));
     void blink(uint32_t speed = 300);
     void breath();