diff --git a/.gitmodules b/.gitmodules
index e0914e0..92a46cc 100644
--- a/.gitmodules
+++ b/.gitmodules
@@ -6,3 +6,7 @@
 	url = https://git.shimatta.de/mhu/c-style-checker.git
 	branch = master
 
+[submodule "stm-firmware/base64-lib"]
+	path = stm-firmware/base64-lib
+	url = https://git.shimatta.de/mhu/base64-lib.git
+	branch = master
diff --git a/stm-firmware/base64-lib b/stm-firmware/base64-lib
new file mode 160000
index 0000000..2035cf0
--- /dev/null
+++ b/stm-firmware/base64-lib
@@ -0,0 +1 @@
+Subproject commit 2035cf0ad859d9d71408fa18614b5a45251719ce