diff --git a/.hgsub b/.hgsub
new file mode 100644
index 0000000..bad6fe8
--- /dev/null
+++ b/.hgsub
@@ -0,0 +1 @@
+thirdparty libraries/TinyWireM = [git]https://github.com/SpenceKonde/TinyWireM.git
diff --git a/.hgsubstate b/.hgsubstate
new file mode 100644
index 0000000..1ca75f7
--- /dev/null
+++ b/.hgsubstate
@@ -0,0 +1 @@
+9d093a2eeb0f9e20fc2276c6e999a7322da46792 thirdparty libraries/TinyWireM