diff --git a/include/zh_avr_ac_dimmer.h b/include/zh_avr_ac_dimmer.h
index 4fd7ac4..fb5785d 100644
--- a/include/zh_avr_ac_dimmer.h
+++ b/include/zh_avr_ac_dimmer.h
@@ -7,7 +7,7 @@
 #include "avr/interrupt.h"
 #include "util/delay.h"
 
-#define ZH_TRIAC_TIME 2 // Triac turn-on time (in microseconds). Depends on the type of triac. Tested on BTA16-600.
+#define ZH_TRIAC_TIME 1 // Triac turn-on time (in microseconds). Depends on the type of triac. Tested on BTA16-600.
 
 #define ZH_AVR_AC_DIMMER_INIT_CONFIG_DEFAULT() \
     {                                          \
diff --git a/zh_avr_ac_dimmer.c b/zh_avr_ac_dimmer.c
index a11fd76..dff7925 100644
--- a/zh_avr_ac_dimmer.c
+++ b/zh_avr_ac_dimmer.c
@@ -5,6 +5,7 @@ volatile static bool _is_dimmer_work = false;
 volatile static uint8_t _dimmer_value = 0;
 volatile static uint8_t _dimmer_count = 0;
 static bool _is_initialized = false;
+volatile static bool _is_zero_crossing = false;
 
 static avr_err_t _zh_avr_ac_dimmer_validate_config(const zh_avr_ac_dimmer_init_config_t *config);
 static void _zh_avr_ac_dimmer_gpio_init(void);
@@ -54,18 +55,28 @@ void zh_avr_ac_dimmer_isr_handler(void)
     case AVR_PORTB:
         if ((PINB & (1 << _init_config.zero_cross_gpio)) == (1 << _init_config.zero_cross_gpio))
         {
+            PORTB &= ~(1 << _init_config.triac_gpio);
             flag = true;
         }
         break;
     case AVR_PORTC:
         if ((PINC & (1 << _init_config.zero_cross_gpio)) == (1 << _init_config.zero_cross_gpio))
         {
+            PORTC &= ~(1 << _init_config.triac_gpio);
             flag = true;
         }
         break;
     case AVR_PORTD:
-        if ((PIND & (1 << _init_config.zero_cross_gpio)) == (1 << _init_config.zero_cross_gpio))
+        if (((PIND & (1 << _init_config.zero_cross_gpio)) == (1 << _init_config.zero_cross_gpio)) && _is_zero_crossing == false)
         {
+            PORTD &= ~(1 << _init_config.triac_gpio);
+            // flag = true;
+            _is_zero_crossing = true;
+        }
+        if (((PIND & (1 << _init_config.zero_cross_gpio)) == 0) && _is_zero_crossing == true)
+        {
+            // PORTD &= ~(1 << _init_config.triac_gpio);
+            _is_zero_crossing = false;
             flag = true;
         }
         break;
@@ -77,24 +88,26 @@ void zh_avr_ac_dimmer_isr_handler(void)
     {
         if (_dimmer_value != 0)
         {
-            if (_dimmer_value >= 100)
+            if (_dimmer_value == 100)
             {
+                // cli();
                 TIMSK0 &= ~(1 << OCIE0A);
+                // sei();
                 switch (_init_config.triac_port)
                 {
                 case AVR_PORTB:
                     PORTB |= (1 << _init_config.triac_gpio);
-                    _delay_us(ZH_TRIAC_TIME);
-                    PORTB &= ~(1 << _init_config.triac_gpio);
+                    // _delay_us(ZH_TRIAC_TIME);
+                    // PORTB &= ~(1 << _init_config.triac_gpio);
                     break;
                 case AVR_PORTC:
                     PORTC |= (1 << _init_config.triac_gpio);
-                    _delay_us(ZH_TRIAC_TIME);
-                    PORTC &= ~(1 << _init_config.triac_gpio);
+                    // _delay_us(ZH_TRIAC_TIME);
+                    // PORTC &= ~(1 << _init_config.triac_gpio);
                 case AVR_PORTD:
                     PORTD |= (1 << _init_config.triac_gpio);
-                    _delay_us(ZH_TRIAC_TIME);
-                    PORTD &= ~(1 << _init_config.triac_gpio);
+                    // _delay_us(10);
+                    // PORTD &= ~(1 << _init_config.triac_gpio);
                     break;
                 default:
                     break;
@@ -102,11 +115,11 @@ void zh_avr_ac_dimmer_isr_handler(void)
             }
             else
             {
-                cli();
+                // cli();
                 TCNT0 = 0;
-                // TIFR0 = (1 << OCF0A);
+                TIFR0 = (1 << OCF0A);
                 TIMSK0 |= (1 << OCIE0A);
-                sei();
+                // sei();
             }
         }
     }
@@ -176,7 +189,7 @@ static avr_err_t _zh_avr_ac_dimmer_timer_init(void)
         switch (_init_config.ac_dimmer_frequency)
         {
         case ZH_50HZ:
-            OCR0A = 99;
+            OCR0A = 94; // Check. 99
             TCCR0B |= (1 << CS01);
             break;
         case ZH_60HZ:
@@ -239,7 +252,7 @@ static avr_err_t _zh_avr_ac_dimmer_timer_init(void)
 ISR(TIMER0_COMPA_vect)
 {
     ++_dimmer_count;
-    if (_dimmer_count >= (100 - _dimmer_value))
+    if (_dimmer_count == (100 - _dimmer_value))
     {
         _dimmer_count = 0;
         TIMSK0 &= ~(1 << OCIE0A);
@@ -263,5 +276,6 @@ ISR(TIMER0_COMPA_vect)
             break;
         }
     }
+    TIFR0 = (1 << OCF0A);
     // ++_dimmer_count;
 }
\ No newline at end of file