diff --git a/.gitignore b/.gitignore
index 06f44c7..bfc204f 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,7 +1,6 @@
 # These are files and directories that the user is instructed to create during
 # the normal build process. Don't offer to commit them to git.
 */build
-pico-sdk
 
 # Ignores like this that are specific to operating environments are better
 # expressed in your user-global ignores, because every environment creates
diff --git a/.gitmodules b/.gitmodules
new file mode 100644
index 0000000..32cf4fb
--- /dev/null
+++ b/.gitmodules
@@ -0,0 +1,3 @@
+[submodule "MCUME_pico2/pico-sdk"]
+	path = MCUME_pico2/pico-sdk
+	url = https://github.com/raspberrypi/pico-sdk
diff --git a/MCUME_pico2/pico-sdk b/MCUME_pico2/pico-sdk
new file mode 160000
index 0000000..bddd20f
--- /dev/null
+++ b/MCUME_pico2/pico-sdk
@@ -0,0 +1 @@
+Subproject commit bddd20f928ce76142793bef434d4f75f4af6e433