diff --git a/README.md b/README.md
index 7c16750..a9c6db2 100644
--- a/README.md
+++ b/README.md
@@ -6,8 +6,8 @@ First semester:
 
 Second semester:
 
-...
-
+- Arduino sound synthesis: [Code](https://git.dm1sh.ru/dm1sh/arduino_speaker)
+ 
 Third semester:
 
 - [Gravitational lensing](./Gravitational_lensing.md)