diff --git a/zh_ac_dimmer.c b/zh_ac_dimmer.c
index de05406..d76772c 100644
--- a/zh_ac_dimmer.c
+++ b/zh_ac_dimmer.c
@@ -105,7 +105,7 @@ esp_err_t _zh_ac_dimmer_gpio_init(const zh_ac_dimmer_init_config_t *config)
     esp_err_t err = gpio_config(&triac_gpio_config);
     ZH_ERROR_CHECK(err == ESP_OK, err, "Triac GPIO configuration failed.");
     gpio_config_t zero_cross_gpio_config = {
-        .intr_type = GPIO_INTR_ANYEDGE,
+        .intr_type = GPIO_INTR_NEGEDGE ,
         .mode = GPIO_MODE_INPUT,
         .pin_bit_mask = (1ULL << config->zero_cross_gpio),
         .pull_down_en = GPIO_PULLDOWN_DISABLE,
@@ -119,7 +119,7 @@ esp_err_t _zh_ac_dimmer_gpio_init(const zh_ac_dimmer_init_config_t *config)
 
 esp_err_t _zh_ac_dimmer_interrupt_init(const zh_ac_dimmer_init_config_t *config)
 {
-    esp_err_t err = gpio_install_isr_service(ESP_INTR_FLAG_LOWMED);
+    esp_err_t err = gpio_install_isr_service(ESP_INTR_FLAG_LEVEL3);
     ZH_ERROR_CHECK(err == ESP_OK, err, "Failed install isr service.")
     err = gpio_isr_handler_add(config->zero_cross_gpio, _zh_ac_dimmer_isr_handler, NULL);
     ZH_ERROR_CHECK(err == ESP_OK, err, "Failed add isr handler.");
@@ -145,28 +145,28 @@ esp_err_t _zh_ac_dimmer_timer_init(void)
     return ESP_OK;
 }
 
-void  _zh_ac_dimmer_isr_handler(void *arg)
+void IRAM_ATTR _zh_ac_dimmer_isr_handler(void *arg)
 {
     if (_is_dimmer_work == false)
     {
         return;
     }
-    if (gpio_get_level(_init_config.zero_cross_gpio) == 1)
-    {
-        gpio_set_level(_init_config.triac_gpio, 0);
-        if (_current_micros == 0)
+    gpio_set_level(_init_config.triac_gpio, 0);
+    // if (gpio_get_level(_init_config.zero_cross_gpio) == 1)
+    // {
+    //     gpio_set_level(_init_config.triac_gpio, 0);
+    // }
+    // else
+    // {
+        uint64_t time = esp_timer_get_time();
+        _current_frequency = time - _current_micros;
+        if (_current_frequency < 1000)
         {
-            return;
-        }
-        _current_frequency = esp_timer_get_time() - _current_micros;
-    }
-    else
-    {
-        _current_micros = esp_timer_get_time();
-        if (_current_frequency == 0)
-        {
-            return;
+            _current_frequency = _old_frequency;
         }
+        // ESP_DRAM_LOGI(TAG, "%d", _current_frequency);
+        _current_micros = time;
+        _old_frequency = _current_frequency;
         if (_dimmer_value != 0)
         {
             if (_dimmer_value == 100)
@@ -176,14 +176,13 @@ void  _zh_ac_dimmer_isr_handler(void *arg)
             }
             // ESP_DRAM_LOGI(TAG, "%d", _current_frequency);
             gptimer_alarm_config_t alarm_config = {
-                .alarm_count = (9000/ 100) * (100 - _dimmer_value),
+                .alarm_count = (_current_frequency / 100) * (100 - _dimmer_value),
                 .flags.auto_reload_on_alarm = false,
             };
             gptimer_set_alarm_action(_dimmer_timer, &alarm_config);
             gptimer_start(_dimmer_timer);
         }
-    }
-    // ESP_DRAM_LOGI(TAG, "%d", _current_frequency);
+    // }
 }
 
 bool _zh_ac_dimmer_timer_on_alarm_cb(gptimer_handle_t timer, const gptimer_alarm_event_data_t *edata, void *user_ctx)
@@ -192,5 +191,5 @@ bool _zh_ac_dimmer_timer_on_alarm_cb(gptimer_handle_t timer, const gptimer_alarm
     gptimer_stop(_dimmer_timer);
     gptimer_set_raw_count(_dimmer_timer, 0);
     // gpio_set_level(_init_config.triac_gpio, 0);
-    return false;
+    return true;
 }
\ No newline at end of file