From f5de7a7cecebadf6287038cebdc95780a133d1aa Mon Sep 17 00:00:00 2001
From: Brendan Haines <brendan.haines@gmail.com>
Date: Wed, 8 Apr 2020 14:23:01 -0600
Subject: [PATCH] fix parsing of controller model

---
 Software/python/server.py | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/Software/python/server.py b/Software/python/server.py
index 2bd3bed..b6bf5f0 100644
--- a/Software/python/server.py
+++ b/Software/python/server.py
@@ -1,5 +1,7 @@
 import time
 import numpy as np
+from scipy import signal
+from scipy.signal import TransferFunction
 
 import board
 import busio
@@ -205,7 +207,7 @@ def stop_controller(attrname=None, old=None, new=None):
 def update_models(attrname=None, old=None, new=None):
     stop_controller()
     try:
-        exec(controller_model_text.value)
+        exec("global D\n" + controller_model_text.value)
         print("INFO: controller model updated")
         print(D)
     except: