diff --git a/V1/switch.c b/V1/switch.c
new file mode 100644
index 0000000..3527208
--- /dev/null
+++ b/V1/switch.c
@@ -0,0 +1,15 @@
+/* 
+ * switch.c
+ * How to register an button and count this
+ * author: Simon Wörner, Manuel Vögele,
+ * 	   Siegfried Kienzle
+ * 24-March-2017
+ * 
+ * */
+
+//Source: http://elinux.org/RPi_GPIO_Code_Samples:
+#define BCM2837_PERIPHERIAL_BASE 0x3F000000
+#define GPIO_BASE (BCM2837_PERIPHERIAL_BASE + 0x3F000000) 
+
+
+