diff --git a/src/main/java/com/r35157/driver/ledsign/LedSign.java b/src/main/java/com/r35157/driver/ledsign/LedSign.java
new file mode 100644
index 0000000..5787d89
--- /dev/null
+++ b/src/main/java/com/r35157/driver/ledsign/LedSign.java
@@ -0,0 +1,5 @@
+package com.r35157.driver.ledsign;
+
+public interface LedSign {
+    void sendCommand(byte[] payload);
+}
diff --git a/src/main/java/com/r35157/driver/ledsign/SomeInterface.java b/src/main/java/com/r35157/driver/ledsign/SomeInterface.java
deleted file mode 100644
index 2594bf5..0000000
--- a/src/main/java/com/r35157/driver/ledsign/SomeInterface.java
+++ /dev/null
@@ -1,6 +0,0 @@
-package com.r35157.driver.ledsign;
-
-public interface SomeInterface {
-    String concat(String x, String y);
-    void divideByZero() throws ArithmeticException;
-}