diff --git a/.gitignore b/.gitignore
index ad13b3f..c433285 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,6 +1,10 @@
 # Visual Studio Code
 .vscode
 
+# Docker compose environment variables
+.env
+
 # Ignore downloaded dataset files
-src/dataset/*
-!src/dataset/*.py
+src/dataset/data/*
+src/dataset/nclt
+!src/dataset/data/*.py
diff --git a/.gitmodules b/.gitmodules
new file mode 100644
index 0000000..d41a877
--- /dev/null
+++ b/.gitmodules
@@ -0,0 +1,4 @@
+[submodule "polex"]
+	path = src/polex
+	url = https://github.com/Mobile-Robotics-W20-Team-9/polex.git
+	branch = master
diff --git a/src/.env b/src/.env
deleted file mode 100644
index 41f3f94..0000000
--- a/src/.env
+++ /dev/null
@@ -1,3 +0,0 @@
-# .env for docker-compose
-
-IP_ADDRESS=192.168.1.14
\ No newline at end of file
diff --git a/src/polex b/src/polex
new file mode 160000
index 0000000..93ac62b
--- /dev/null
+++ b/src/polex
@@ -0,0 +1 @@
+Subproject commit 93ac62b154f9addc9cdad74c2da8d2ee56d0173f