Update README.md

README.md

@@ -162,4 +162,9 @@ A 3d-printable housing can be found here: https://www.thingiverse.com/thing:4571
 
 ## Solved topics
 
-* n.a.
+* n.a.
+
+
+## Donate
+
+https://www.paypal.com/donate?hosted_button_id=8TRSVYNYKDSWL