diff --git a/version.txt b/version.txt
index 7f20734..e6d5cb8 100644
--- a/version.txt
+++ b/version.txt
@@ -1 +1 @@
-1.0.1
\ No newline at end of file
+1.0.2
\ No newline at end of file
diff --git a/zh_avr_ac_dimmer.c b/zh_avr_ac_dimmer.c
index 2f0122b..75f5af1 100644
--- a/zh_avr_ac_dimmer.c
+++ b/zh_avr_ac_dimmer.c
@@ -52,19 +52,19 @@ void zh_avr_ac_dimmer_isr_handler(void)
     switch (_init_config.zero_cross_port)
     {
     case AVR_PORTB:
-        if ((PINB & (1 << _init_config.zero_cross_gpio)) == 0)
+        if ((PINB & _init_config.zero_cross_gpio) == _init_config.zero_cross_gpio)
         {
             flag = true;
         }
         break;
     case AVR_PORTC:
-        if ((PINC & (1 << _init_config.zero_cross_gpio)) == 0)
+        if ((PINC & _init_config.zero_cross_gpio) == _init_config.zero_cross_gpio)
         {
             flag = true;
         }
         break;
     case AVR_PORTD:
-        if ((PIND & (1 << _init_config.zero_cross_gpio)) == 0)
+        if ((PIND & _init_config.zero_cross_gpio) == _init_config.zero_cross_gpio)
         {
             flag = true;
         }