diff --git a/camera.py b/camera.py
index 97af0f4..cbaa30e 100755
--- a/camera.py
+++ b/camera.py
@@ -25,6 +25,7 @@ def read_old_time():
 
 
 def main():
+    # minimum write time
     record_time = 60
 
     os.system("echo 0 > /tmp/sensor")