diff --git a/inc/pwmout.h b/inc/pwmout.h
--- a/inc/pwmout.h
+++ b/inc/pwmout.h
@@ -2,6 +2,12 @@
 #define PWMOUT_H
 
 
+#define SSR_PIN GPIO_PIN_7
+#define SSR_GPIO_Port GPIOB
+#define SSR SSR_GPIO_Port, SSR_PIN
+
+
+
 void pwmout_init(void);
 void pwmout_process(float duty);