From 6fe13ff9a66921f38bb7c9a2affffc883ca8801d Mon Sep 17 00:00:00 2001
From: Waldemar Porscha <waldemar.porscha@sap.com>
Date: Sun, 27 Feb 2022 13:00:02 +0100
Subject: [PATCH] Feature: Uninitialized GO handling - don't send senseless
 values on GroupValueRead

---
 src/knx/group_object.cpp | 7 +++++++
 src/knx/group_object.h   | 5 +++--
 2 files changed, 10 insertions(+), 2 deletions(-)

diff --git a/src/knx/group_object.cpp b/src/knx/group_object.cpp
index db92058..6f19247 100644
--- a/src/knx/group_object.cpp
+++ b/src/knx/group_object.cpp
@@ -74,6 +74,10 @@ bool GroupObject::readEnable()
     if (!_table)
         return false;
 
+    // we forbid reading of new (uninitialized) go
+    if (_commFlag == Uninitialized)
+        return false;
+
     return bitRead(ntohs(_table->_tableData[_asap]), 11) > 0;
 }
 
@@ -270,5 +274,8 @@ void GroupObject::valueNoSend(const KNXValue& value)
 
 void GroupObject::valueNoSend(const KNXValue& value, const Dpt& type)
 {
+    if (_commFlag == Uninitialized)
+        _commFlag = Ok;
+
     KNX_Encode_Value(value, _data, _dataLength, type);
 }
diff --git a/src/knx/group_object.h b/src/knx/group_object.h
index 91c8b56..88ce274 100644
--- a/src/knx/group_object.h
+++ b/src/knx/group_object.h
@@ -14,7 +14,8 @@ enum ComFlag
     WriteRequest = 2, //!< Write was requested but was not processed
     Transmitting = 3, //!< Group Object is processed a the moment (read or write)
     Ok = 4,           //!< read or write request were send successfully
-    Error = 5         //!< there was an error on processing a request
+    Error = 5,        //!< there was an error on processing a request
+    Uninitialized = 6 //!< uninitialized Group Object, its value is not valid
 };
 
 class GroupObject;
@@ -235,7 +236,7 @@ class GroupObject
     size_t asapValueSize(uint8_t code);
     size_t goSize();
     uint16_t _asap = 0;
-    ComFlag _commFlag = Ok;
+    ComFlag _commFlag = Uninitialized;
     uint8_t* _data = 0;
     uint8_t _dataLength = 0;
 #ifndef SMALL_GROUPOBJECT