diff --git a/src/zero_cross_detection/zero_cross_detection.c b/src/zero_cross_detection/zero_cross_detection.c
index 0d4cbae..6099609 100644
--- a/src/zero_cross_detection/zero_cross_detection.c
+++ b/src/zero_cross_detection/zero_cross_detection.c
@@ -15,6 +15,8 @@
 #include "MockADC/MockADC.h"
 #endif
 
+#define ZCD_PIN 0x07
+
 void ZCD_Setup(void)
 {
     ADC_Init(7);
@@ -25,11 +27,11 @@ bool ZCD_IsTriggered()
 {
     uint16_t first, second;
     ZCD_Setup();
-    first = ADC_ReadValue(7);
+    first = ADC_ReadValue(ZCD_PIN);
     ADC_Disable();
     
     ZCD_Setup();
-    second = ADC_ReadValue(7);
+    second = ADC_ReadValue(ZCD_PIN);
     ADC_Disable();
 
     if(second < TRIGGERVAL){