diff --git a/.gitmodules b/.gitmodules
new file mode 100644
index 0000000..05c4d95
--- /dev/null
+++ b/.gitmodules
@@ -0,0 +1,3 @@
+[submodule "lib/state-machine"]
+	path = lib/state-machine
+	url = https://github.com/t-liu93/state-machine
diff --git a/lib/state-machine b/lib/state-machine
new file mode 160000
index 0000000..fc7d0d9
--- /dev/null
+++ b/lib/state-machine
@@ -0,0 +1 @@
+Subproject commit fc7d0d97067f40f5131a1336d2dea1a3117151c3
diff --git a/src/main.cpp b/src/main.cpp
index d5bc921..790a2be 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -4,6 +4,7 @@
 #include "network.h"
 #include "ota.h"
 #include "pin.h"
+#include "statemachine.hpp"
 #include "TaskScheduler.h"
 #include "wifimanager.h"