diff --git a/firmware/keyboard.c b/firmware/keyboard.c
index 440c6cf..41fee8a 100644
--- a/firmware/keyboard.c
+++ b/firmware/keyboard.c
@@ -4,7 +4,7 @@
 #include "rtc.h"
 #include "led.h"
 
-uint8_t k_inc_hour, k_inc_minute, k_inc_second;
+uint8_t k_inc_hour, k_inc_minute, k_inc_second, k_inc_brightness;
 
 void inc_hour(void)
 {
@@ -24,10 +24,16 @@ void inc_second(void)
   rtc_set_time(SECOND, led_second);
 }
 
+void inc_brightness(void)
+{
+  led_brightness <<= 1;
+  if(!led_brightness) led_brightness = 1;
+}
+
 void keyboard_init(void)
 {
-  KEYBOARD_DIR &= ~(KEY_INC_HOUR | KEY_INC_MINUTE | KEY_INC_SECOND);
-  PORTB |= KEY_INC_HOUR | KEY_INC_MINUTE | KEY_INC_SECOND;
+  KEYBOARD_DIR &= ~(KEY_INC_HOUR | KEY_INC_MINUTE | KEY_INC_SECOND | KEY_INC_BRIGHTNESS);
+  PORTB |= KEY_INC_HOUR | KEY_INC_MINUTE | KEY_INC_SECOND | KEY_INC_BRIGHTNESS;
 }
 
 void keyboard_handle_input(void)
@@ -35,4 +41,5 @@ void keyboard_handle_input(void)
   SuperDebounce(&k_inc_hour, &KEYBOARD_PIN, KEY_INC_HOUR, 20, 500, &inc_hour, &inc_hour);
   SuperDebounce(&k_inc_minute, &KEYBOARD_PIN, KEY_INC_MINUTE, 20, 500, &inc_minute, &inc_minute);
   SuperDebounce(&k_inc_second, &KEYBOARD_PIN, KEY_INC_SECOND, 20, 500, &inc_second, &inc_second);
+  SuperDebounce(&k_inc_brightness, &KEYBOARD_PIN, KEY_INC_BRIGHTNESS, 20, 500, &inc_brightness, &inc_brightness);
 }
\ No newline at end of file
diff --git a/firmware/keyboard.h b/firmware/keyboard.h
index ffb139e..8d351c7 100644
--- a/firmware/keyboard.h
+++ b/firmware/keyboard.h
@@ -7,6 +7,7 @@
 #define KEY_INC_HOUR (1<<PB0)
 #define KEY_INC_MINUTE (1<<PB1)
 #define KEY_INC_SECOND (1<<PB2)
+#define KEY_INC_BRIGHTNESS (1<<PB3)
 
 void keyboard_init(void);
 void keyboard_handle_input(void);
diff --git a/firmware/led.c b/firmware/led.c
index a477db4..7f81fa4 100644
--- a/firmware/led.c
+++ b/firmware/led.c
@@ -2,8 +2,7 @@
 #include <avr/interrupt.h>
 #include "led.h"
 
-#define SET_LED(PORT, IDX, NUM) PORT = ((PORT & ~(1<<(IDX))) | (~(NUM) & 1<<(IDX)))
-
+volatile uint8_t led_brightness = 1;
 volatile uint8_t led_hour;
 volatile uint8_t led_minute;
 volatile uint8_t led_second;
@@ -12,66 +11,48 @@ void led_init(void)
 {
   // Set outputs
   ANODES_DIR |= HOUR_ANODE | MINUTE_ANODE | SECOND_ANODE; 
-  LED0_DIR |= LED0; 
-  LED1_DIR |= LED1; 
-  LED2_DIR |= LED2; 
-  LED3_DIR |= LED3; 
-  LED4_DIR |= LED4; 
-  LED5_DIR |= LED5; 
+  LED_DIR |= 0x3F; // 0b00111111
 
   // Clear LEDs
   ANODES_PORT = HOUR_ANODE | MINUTE_ANODE | SECOND_ANODE;
-  LED0_PORT |= LED0;
-  LED1_PORT |= LED1;
-  LED2_PORT |= LED2;
-  LED3_PORT |= LED3;
-  LED4_PORT |= LED4;
-  LED5_PORT |= LED5;
+  LED_PORT |= 0x3F; // 0b00111111
 
-  TCCR0 |= (1<<WGM01); // CTC Mode
-  TCCR0 |= (1<<CS02) | (1<<CS00); // Prescaler 1024
-  OCR0 = 38; // 200Hz
-  TIMSK |= (1<<OCIE0); // Enable CTC interruptions
+  TCCR0 |= (1<<CS00);
+  TIMSK |= (1<<TOIE0);
 }
 
-ISR(TIMER0_COMP_vect) 
+// ISR(TIMER0_COMP_vect) 
+ISR(TIMER0_OVF_vect)
 {
-  static uint8_t counter = 1;    
+  static uint8_t pwm_counter = 0;
+  static uint8_t counter = 0;
+  static uint8_t curr_anode = 1;    
 
-  switch(counter) {
-    case 1: 
-      ANODES_PORT = ~HOUR_ANODE;
-      SET_LED(LED0_PORT, 0, led_hour);
-      SET_LED(LED1_PORT, 1, led_hour);
-      SET_LED(LED2_PORT, 2, led_hour);
-      SET_LED(LED3_PORT, 3, led_hour);
-      SET_LED(LED4_PORT, 4, led_hour);
-      SET_LED(LED5_PORT, 5, led_hour);
-      break;
-    case 2: 
-      ANODES_PORT = ~MINUTE_ANODE;
-      SET_LED(LED0_PORT, 0, led_minute);
-      SET_LED(LED1_PORT, 1, led_minute);
-      SET_LED(LED2_PORT, 2, led_minute);
-      SET_LED(LED3_PORT, 3, led_minute);
-      SET_LED(LED4_PORT, 4, led_minute);
-      SET_LED(LED5_PORT, 5, led_minute);
-      break;
-    case 4: 
-      ANODES_PORT = ~SECOND_ANODE;
-      SET_LED(LED0_PORT, 0, led_second);
-      SET_LED(LED1_PORT, 1, led_second);
-      SET_LED(LED2_PORT, 2, led_second);
-      SET_LED(LED3_PORT, 3, led_second);
-      SET_LED(LED4_PORT, 4, led_second);
-      SET_LED(LED5_PORT, 5, led_second);
-      break;
+  switch(curr_anode) 
+    {
+      case 1: 
+        LED_PORT = ~led_hour;   
+        ANODES_PORT = led_brightness >= pwm_counter ? ~HOUR_ANODE : 0xFF;
+        break;
+      case 2: 
+        LED_PORT = ~led_minute;   
+        ANODES_PORT = led_brightness >= pwm_counter ? ~MINUTE_ANODE : 0xFF;  
+        break;
+      case 4: 
+        LED_PORT = ~led_second;
+        ANODES_PORT = led_brightness >= pwm_counter ? ~SECOND_ANODE : 0xFF; 
+        break;
+    }
+
+  if(!counter)
+  {    
+    curr_anode <<= 1;
+
+    if(curr_anode > 4) curr_anode = 1;          
+
+    counter = 250;
   }
 
-  counter <<= 1;
-
-  if(counter > 4) 
-  {
-    counter = 1;        
-  }
+  --counter;
+  ++pwm_counter;
 }
\ No newline at end of file
diff --git a/firmware/led.h b/firmware/led.h
index 7fbeb3b..9981c43 100644
--- a/firmware/led.h
+++ b/firmware/led.h
@@ -1,24 +1,8 @@
 #ifndef __LED_H__
 #define __LED_H__
 
-#define LED0_PORT PORTA
-#define LED0_DIR DDRA
-#define LED0 (1<<0)
-#define LED1_PORT PORTA
-#define LED1_DIR DDRA
-#define LED1 (1<<1)
-#define LED2_PORT PORTA
-#define LED2_DIR DDRA
-#define LED2 (1<<2)
-#define LED3_PORT PORTA
-#define LED3_DIR DDRA
-#define LED3 (1<<3)
-#define LED4_PORT PORTA
-#define LED4_DIR DDRA
-#define LED4 (1<<4)
-#define LED5_PORT PORTA
-#define LED5_DIR DDRA
-#define LED5 (1<<5)
+#define LED_PORT PORTA
+#define LED_DIR DDRA
 
 #define ANODES_PORT PORTD
 #define ANODES_DIR DDRD
@@ -26,6 +10,7 @@
 #define MINUTE_ANODE (1<<PD6)
 #define SECOND_ANODE (1<<PD7)
 
+extern volatile uint8_t led_brightness;
 extern volatile uint8_t led_hour;
 extern volatile uint8_t led_minute;
 extern volatile uint8_t led_second;