diff --git a/go/controller.go b/go/controller.go
new file mode 100644
index 0000000..644cff2
--- /dev/null
+++ b/go/controller.go
@@ -0,0 +1,5 @@
+package controller
+func SelectMode(sensor int) int {
+    if sensor > 80 { return 2 }
+    return 1
+}