diff --git a/README.md b/README.md
index 5181aa0..ab668b2 100644
--- a/README.md
+++ b/README.md
@@ -1,2 +1,55 @@
-# zh_avr_ac_dimmer
+# FreeRTOS based AVR library for AC dimmer
 
+## Features
+
+1. Support of 50 Hz, 60 Hz and 400 Hz power frequency.
+
+## Dependencies
+
+1. [zh_avr_common](http://git.zh.com.ru/avr_libraries/zh_avr_common)
+
+## Using
+
+In an existing project, run the following command to install the components:
+
+```text
+cd ../your_project/lib
+git clone http://git.zh.com.ru/avr_libraries/zh_avr_common
+git clone http://git.zh.com.ru/avr_libraries/zh_avr_ac_dimmer
+```
+
+In the application, add the component:
+
+```c
+#include "zh_avr_ac_dimmer.h"
+```
+
+## Examples
+
+```c
+#include "zh_avr_ac_dimmer.h"
+
+int main(void)
+{
+    zh_avr_ac_dimmer_init_config_t ac_dimmer_init_config = ZH_AVR_AC_DIMMER_INIT_CONFIG_DEFAULT();
+    ac_dimmer_init_config.ac_dimmer_frequency = ZH_50HZ;
+    ac_dimmer_init_config.zero_cross_port = AVR_PORTD;
+    ac_dimmer_init_config.zero_cross_gpio = PORTD2;
+    ac_dimmer_init_config.triac_port = AVR_PORTD;
+    ac_dimmer_init_config.triac_gpio = PORTD3;
+    zh_avr_ac_dimmer_init(&ac_dimmer_init_config);
+    zh_avr_ac_dimmer_set(50);
+    zh_avr_ac_dimmer_start();
+    for (;;)
+    {
+    }
+    return 0;
+}
+
+// ISR(PCINT0_vect) // For AVR_PORTB.
+// ISR(PCINT1_vect) // For AVR_PORTC.
+ISR(PCINT2_vect) // For AVR_PORTD.
+{
+    zh_avr_ac_dimmer_isr_handler();
+}
+```
diff --git a/include/zh_avr_ac_dimmer.h b/include/zh_avr_ac_dimmer.h
index fd71481..ecba712 100644
--- a/include/zh_avr_ac_dimmer.h
+++ b/include/zh_avr_ac_dimmer.h
@@ -23,8 +23,8 @@ extern "C"
     typedef enum
     {
         ZH_50HZ = 1,
-        ZH_60HZ,
-        ZH_400HZ
+        ZH_60HZ = 2,
+        ZH_400HZ = 3
     } zh_avr_ac_dimmer_frequency_t;
 
     typedef struct // Structure for initial initialization of AC dimmer.
@@ -72,6 +72,11 @@ extern "C"
      */
     avr_err_t zh_avr_ac_dimmer_set(uint8_t value);
 
+    /**
+     * @brief AC dimmer ISR handler.
+     */
+    void zh_avr_ac_dimmer_isr_handler(void);
+
 #ifdef __cplusplus
 }
 #endif
\ No newline at end of file
diff --git a/triac_400hz_delay — копия.xlsx b/triac_400hz_delay — копия.xlsx
deleted file mode 100644
index aa41f37..0000000
Binary files a/triac_400hz_delay — копия.xlsx and /dev/null differ
diff --git a/triac_400hz_delay.xlsx b/triac_400hz_delay.xlsx
deleted file mode 100644
index aa41f37..0000000
Binary files a/triac_400hz_delay.xlsx and /dev/null differ
diff --git a/zh_avr_ac_dimmer.c b/zh_avr_ac_dimmer.c
index cbfb82e..e37abfc 100644
--- a/zh_avr_ac_dimmer.c
+++ b/zh_avr_ac_dimmer.c
@@ -1,81 +1,115 @@
 #include "zh_avr_ac_dimmer.h"
 
+static zh_avr_ac_dimmer_init_config_t _init_config = {0};
 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;
+static uint8_t _prescaler = 0;
 
 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);
+static avr_err_t _zh_avr_ac_dimmer_timer_init(void);
 
-static avr_err_t zh_avr_ac_dimmer_init(const zh_avr_ac_dimmer_init_config_t *config)
+avr_err_t zh_avr_ac_dimmer_init(const zh_avr_ac_dimmer_init_config_t *config)
 {
     ZH_ERROR_CHECK(_is_initialized == false, AVR_ERR_INVALID_STATE);
-    avr_err_t err = _zh_avr_pcf8574_validate_config(config);
+    avr_err_t err = _zh_avr_ac_dimmer_validate_config(config);
     ZH_ERROR_CHECK(err == AVR_OK, err);
-    switch (config->zero_cross_port)
-    {
-    case AVR_PORTB:
-        DDRB &= ~(1 << config->zero_cross_gpio);
-        PORTB |= (1 << config->zero_cross_gpio);
-        PCICR |= (1 << PCIE0);
-        PCMSK0 |= (1 << config->zero_cross_gpio);
-        break;
-    case AVR_PORTC:
-        DDRC &= ~(1 << config->zero_cross_gpio);
-        PORTC |= (1 << config->zero_cross_gpio);
-        PCICR |= (1 << PCIE1);
-        PCMSK1 |= (1 << config->zero_cross_gpio);
-        break;
-    case AVR_PORTD:
-        DDRD &= ~(1 << config->zero_cross_gpio);
-        PORTD |= (1 << config->zero_cross_gpio);
-        PCICR |= (1 << PCIE2);
-        PCMSK2 |= (1 << config->zero_cross_gpio);
-        break;
-    default:
-        break;
-    }
-    switch (config->triac_port)
-    {
-    case AVR_PORTB:
-        DDRB |= (1 << config->triac_gpio);
-        PORTB &= ~(1 << config->triac_gpio);
-        break;
-    case AVR_PORTC:
-        DDRC |= (1 << config->triac_gpio);
-        PORTC &= ~(1 << config->triac_gpio);
-        break;
-    case AVR_PORTD:
-        DDRD |= (1 << config->triac_gpio);
-        PORTD &= ~(1 << config->triac_gpio);
-        break;
-    default:
-        break;
-    }
+    _init_config = *config;
+    cli();
+    _zh_avr_ac_dimmer_gpio_init();
+    err = _zh_avr_ac_dimmer_timer_init();
+    ZH_ERROR_CHECK(err == AVR_OK, err);
+    sei();
     _is_initialized = true;
     return AVR_OK;
 }
 
-static avr_err_t zh_avr_ac_dimmer_start(void)
+avr_err_t zh_avr_ac_dimmer_start(void)
 {
     ZH_ERROR_CHECK(_is_initialized == true, AVR_ERR_NOT_FOUND);
     _is_dimmer_work = true;
     return AVR_OK;
 }
 
-static avr_err_t zh_avr_ac_dimmer_stop(void)
+avr_err_t zh_avr_ac_dimmer_stop(void)
 {
     ZH_ERROR_CHECK(_is_initialized == true, AVR_ERR_NOT_FOUND);
     _is_dimmer_work = false;
     return AVR_OK;
 }
 
-static avr_err_t zh_avr_ac_dimmer_set(uint8_t value)
+avr_err_t zh_avr_ac_dimmer_set(uint8_t value)
 {
     ZH_ERROR_CHECK(_dimmer_value <= 100, AVR_ERR_INVALID_ARG);
     _dimmer_value = value;
     return AVR_OK;
 }
 
+void zh_avr_ac_dimmer_isr_handler(void)
+{
+    uint8_t flag = false;
+    switch (_init_config.zero_cross_port)
+    {
+    case AVR_PORTB:
+        if ((PINB & (1 << _init_config.zero_cross_gpio)) == 0)
+        {
+            flag = true;
+        }
+        break;
+    case AVR_PORTC:
+        if ((PINC & (1 << _init_config.zero_cross_gpio)) == 0)
+        {
+            flag = true;
+        }
+        break;
+    case AVR_PORTD:
+        if ((PIND & (1 << _init_config.zero_cross_gpio)) == 0)
+        {
+            flag = true;
+        }
+        break;
+    default:
+        break;
+    }
+    if (_is_dimmer_work == true && flag == true)
+    {
+        if (_dimmer_value != 0)
+        {
+            if (_dimmer_value == 100)
+            {
+                switch (_init_config.triac_port)
+                {
+                case AVR_PORTB:
+                    PORTB |= (1 << _init_config.triac_gpio);
+                    asm("nop");
+                    PORTB &= ~(1 << _init_config.triac_gpio);
+                    break;
+                case AVR_PORTC:
+                    PORTC |= (1 << _init_config.triac_gpio);
+                    asm("nop");
+                    PORTC &= ~(1 << _init_config.triac_gpio);
+                    break;
+                case AVR_PORTD:
+                    PORTD |= (1 << _init_config.triac_gpio);
+                    asm("nop");
+                    PORTD &= ~(1 << _init_config.triac_gpio);
+                    break;
+                default:
+                    break;
+                }
+            }
+            else
+            {
+                TCNT0 = 0;
+                TCCR0B |= _prescaler;
+                TIMSK0 |= (1 << OCIE0A);
+            }
+        }
+    }
+}
+
 static avr_err_t _zh_avr_ac_dimmer_validate_config(const zh_avr_ac_dimmer_init_config_t *config)
 {
     ZH_ERROR_CHECK(config != NULL, AVR_ERR_INVALID_ARG);
@@ -85,4 +119,148 @@ static avr_err_t _zh_avr_ac_dimmer_validate_config(const zh_avr_ac_dimmer_init_c
     ZH_ERROR_CHECK(config->triac_port >= AVR_PORTB && config->triac_port <= AVR_PORTD, AVR_ERR_INVALID_ARG);
     ZH_ERROR_CHECK(config->ac_dimmer_frequency >= ZH_50HZ && config->ac_dimmer_frequency <= ZH_400HZ, AVR_ERR_INVALID_ARG);
     return AVR_OK;
+}
+
+static void _zh_avr_ac_dimmer_gpio_init(void)
+{
+    switch (_init_config.zero_cross_port)
+    {
+    case AVR_PORTB:
+        DDRB &= ~(1 << _init_config.zero_cross_gpio);
+        PORTB |= (1 << _init_config.zero_cross_gpio);
+        PCICR |= (1 << PCIE0);
+        PCMSK0 |= (1 << _init_config.zero_cross_gpio);
+        break;
+    case AVR_PORTC:
+        DDRC &= ~(1 << _init_config.zero_cross_gpio);
+        PORTC |= (1 << _init_config.zero_cross_gpio);
+        PCICR |= (1 << PCIE1);
+        PCMSK1 |= (1 << _init_config.zero_cross_gpio);
+        break;
+    case AVR_PORTD:
+        DDRD &= ~(1 << _init_config.zero_cross_gpio);
+        PORTD |= (1 << _init_config.zero_cross_gpio);
+        PCICR |= (1 << PCIE2);
+        PCMSK2 |= (1 << _init_config.zero_cross_gpio);
+        break;
+    default:
+        break;
+    }
+    switch (_init_config.triac_port)
+    {
+    case AVR_PORTB:
+        DDRB |= (1 << _init_config.triac_gpio);
+        PORTB &= ~(1 << _init_config.triac_gpio);
+        break;
+    case AVR_PORTC:
+        DDRC |= (1 << _init_config.triac_gpio);
+        PORTC &= ~(1 << _init_config.triac_gpio);
+        break;
+    case AVR_PORTD:
+        DDRD |= (1 << _init_config.triac_gpio);
+        PORTD &= ~(1 << _init_config.triac_gpio);
+        break;
+    default:
+        break;
+    }
+}
+
+static avr_err_t _zh_avr_ac_dimmer_timer_init(void)
+{
+    TCCR0A |= (1 << WGM01);
+    switch (F_CPU)
+    {
+    case 8000000:
+        switch (_init_config.ac_dimmer_frequency)
+        {
+        case ZH_50HZ:
+            OCR0A = 99;
+            _prescaler = (1 << CS01);
+            break;
+        case ZH_60HZ:
+            OCR0A = 82;
+            _prescaler = (1 << CS01);
+            break;
+        case ZH_400HZ:
+            OCR0A = 99;
+            _prescaler = (1 << CS00);
+            break;
+        default:
+            break;
+        }
+        break;
+    case 16000000:
+        switch (_init_config.ac_dimmer_frequency)
+        {
+        case ZH_50HZ:
+            OCR0A = 24;
+            _prescaler = (1 << CS01) | (1 << CS00);
+            break;
+        case ZH_60HZ:
+            OCR0A = 165;
+            _prescaler = (1 << CS01);
+            break;
+        case ZH_400HZ:
+            OCR0A = 24;
+            _prescaler = (1 << CS01);
+            break;
+        default:
+            break;
+        }
+        break;
+    case 20000000:
+        switch (_init_config.ac_dimmer_frequency)
+        {
+        case ZH_50HZ:
+            OCR0A = 249;
+            _prescaler = (1 << CS01);
+            break;
+        case ZH_60HZ:
+            OCR0A = 206;
+            _prescaler = (1 << CS01);
+            break;
+        case ZH_400HZ:
+            OCR0A = 249;
+            _prescaler = (1 << CS00);
+            break;
+        default:
+            break;
+        }
+        break;
+    default:
+        return AVR_ERR_INVALID_ARG;
+        break;
+    }
+    return AVR_OK;
+}
+
+ISR(TIMER0_COMPA_vect)
+{
+    ++_dimmer_count;
+    if (_dimmer_count == (100 - _dimmer_value))
+    {
+        _dimmer_count = 0;
+        TCCR0B &= ~_prescaler;
+        TIMSK0 &= ~(1 << OCIE0A);
+        switch (_init_config.triac_port)
+        {
+        case AVR_PORTB:
+            PORTB |= (1 << _init_config.triac_gpio);
+            asm("nop");
+            PORTB &= ~(1 << _init_config.triac_gpio);
+            break;
+        case AVR_PORTC:
+            PORTC |= (1 << _init_config.triac_gpio);
+            asm("nop");
+            PORTC &= ~(1 << _init_config.triac_gpio);
+            break;
+        case AVR_PORTD:
+            PORTD |= (1 << _init_config.triac_gpio);
+            asm("nop");
+            PORTD &= ~(1 << _init_config.triac_gpio);
+            break;
+        default:
+            break;
+        }
+    }
 }
\ No newline at end of file