Try tomorrow

device_server.py

@@ -10,7 +10,7 @@ Add addresses to REGISTER_COMMANDS to capture more register ranges.
 
 import os
 import re
-import signal
+import socket
 import subprocess
 import threading
 
@@ -94,7 +94,9 @@ def control_display():
     if state == "on":
         with _video_lock:
             if _video_proc is not None and _video_proc.poll() is None:
-                _video_proc.send_signal(signal.SIGUSR1)
+                _sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
+                _sock.sendto(b'switch', ('127.0.0.1', 5001))
+                _sock.close()
                 return jsonify({"status": "video switched"}), 200
         # fallback when video is not running
         os.system("echo 0 > /sys/class/graphics/fb0/blank")