diff --git a/src/main.cpp b/src/main.cpp
index e857f23..e4c21dc 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -3,15 +3,19 @@
 
 Adafruit_SHT4x sht4 = Adafruit_SHT4x();
 
-void setup() {
-  Serial.begin(9600); // zacni seriovou komunikaci s baudrate 9600
+void setup()
+{
+  Serial.begin(115200); // zacni seriovou komunikaci s baudrate 115200
   Serial.println("UART OK");
 
+  pinMode(LED_BUILTIN, OUTPUT); // nastav ledku na desce jako vystup
+
   Serial.println("Adafruit SHT4x test"); // zadni komunikaci s SHT40 po I2C
-  if (! sht4.begin()) 
+  if (!sht4.begin())
   {
     Serial.println("Couldn't find SHT4x"); // pokud neni sensor nalezen, program skonci v nekonecne smycce
-    while (1) delay(1);
+    while (1)
+      delay(1);
   }
   Serial.println("Found SHT4x sensor");
   Serial.print("Serial number 0x");
@@ -20,11 +24,12 @@ void setup() {
   sht4.setHeater(SHT4X_NO_HEATER);
 }
 
-void loop() {
-  sensors_event_t humidity, temp; 
-  
+void loop()
+{
+  sensors_event_t humidity, temp;
+
   uint32_t timestamp = millis();
-  sht4.getEvent(&humidity, &temp); // cteni ze senzoru
+  sht4.getEvent(&humidity, &temp);  // cteni ze senzoru
   timestamp = millis() - timestamp; // ziskani delky cteni ze senzoru
 
   Serial.print("temp= ");
@@ -32,6 +37,8 @@ void loop() {
   Serial.print(" humidity=");
   Serial.println(humidity.relative_humidity);
 
-  delay(1000);
+  digitalWrite(LED_BUILTIN, HIGH); // turn the LED on (HIGH is the voltage level)
+  delay(250);                      // wait for a second
+  digitalWrite(LED_BUILTIN, LOW);  // turn the LED off by making the voltage LOW
+  delay(250);                      // wait for a second
 }
-