1 files changed, 38 insertions, 0 deletions
diff --git a/gr-blocks/python/blocks/var_to_msg.py b/gr-blocks/python/blocks/var_to_msg.py
new file mode 100644
index 0000000000..77a947ed0c
--- /dev/null
+++ b/gr-blocks/python/blocks/var_to_msg.py
@@ -0,0 +1,38 @@
+#!/usr/bin/env python
+#
+# Copyright 2020 Free Software Foundation, Inc.
+#
+# This file is part of GNU Radio
+#
+# SPDX-License-Identifier: GPL-3.0-or-later
+#
+#
+
+from gnuradio import gr
+import pmt
+
+class var_to_msg_pair(gr.sync_block):
+    """
+    This block will monitor a variable, and when it changes, generate a message.
+    """
+    def __init__(self, pairname):
+        gr.sync_block.__init__(self, name="var_to_msg_pair", in_sig=None, out_sig=None)
+
+        self.pairname = pairname
+
+        self.message_port_register_out(pmt.intern("msgout"))
+
+    def variable_changed(self, value):
+        if type(value) == float:
+            p = pmt.from_float(value)
+        elif type(value) == int:
+            p = pmt.from_long(value)
+        elif type(value) == bool:
+            p = pmt.from_bool(value)
+        else:
+            p = pmt.intern(value)
+
+        self.message_port_pub(pmt.intern("msgout"), pmt.cons(pmt.intern(self.pairname), p))
+
+    def stop(self):
+        return True