diff --git a/demo/controller2knob.py b/demo/controller2knob.py
index d642756..284e22e 100644
--- a/demo/controller2knob.py
+++ b/demo/controller2knob.py
@@ -1,6 +1,7 @@
 import numpy as np
 import concore
 
+ysp = 3.0
 
 def controller(ym): 
   if ym[0] < ysp: