diff --git a/codebug_i2c_tether/core.py b/codebug_i2c_tether/core.py
index 5d94281..73c6c9d 100644
--- a/codebug_i2c_tether/core.py
+++ b/codebug_i2c_tether/core.py
@@ -78,6 +78,16 @@ def clear(self):
 
         """
         self.set_bulk(0, (0,)*5)
+        
+    def fill(self):
+        """Sets all the LED's to on.
+
+            >>> with CodeBug() as codebug:
+            ...     codebug.fill()
+            ...
+
+        """
+        self.set_bulk(0, (31,)*5)             
 
     def set_row(self, row, val):
         """Sets a row of LEDs on CodeBug.