feat: Add enhanced EXI viewer with XML decode capability

- Implement complete CurrentDemandReq/CurrentDemandRes parsing (24 total fields)
- Add enhanced_exi_viewer.c with detailed message analysis
- Support -decode option for clean XML output (file-ready format)
- Enable ISO1, ISO2, DIN codec support in build configuration
- Fix C99 compatibility issues in makefiles (change -ansi to -std=c99)
- Create test utilities for hex string to EXI conversion
- Generate test files: test3.exi (CurrentDemandRes), test4.exi (CurrentDemandReq)

Features:
* Dual output modes: detailed analysis (default) vs XML (-decode)
* Complete V2G message type detection and parsing
* Session ID display in hex and ASCII formats
* Voltage/current/power readings with proper units
* All optional fields and status flags supported

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

src/iso2/iso2EXIDatatypesDecoder.h

@@ -0,0 +1,65 @@
+/*
+ * Copyright (C) 2007-2018 Siemens AG
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published
+ * by the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+/*******************************************************************
+ *
+ * @author Daniel.Peintner.EXT@siemens.com
+ * @version 0.9.4 
+ * @contact Richard.Kuntschke@siemens.com
+ *
+ * <p>Code generated by EXIdizer</p>
+ * <p>Schema: V2G_CI_MsgDef.xsd</p>
+ *
+ *
+ ********************************************************************/
+
+
+
+/**
+ * \file 	EXIDatatypesDecoder.h
+ * \brief 	Decoder for datatype definitions
+ *
+ */
+
+#ifndef EXI_iso2_DATATYPES_DECODER_H
+#define EXI_iso2_DATATYPES_DECODER_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include "iso2EXIDatatypes.h"
+
+#if DEPLOY_ISO2_CODEC == SUPPORT_YES
+
+#include <stdint.h>
+
+#include "EXITypes.h"
+
+int decode_iso2ExiDocument(bitstream_t* stream, struct iso2EXIDocument* exiDoc);
+
+#if DEPLOY_ISO2_CODEC_FRAGMENT == SUPPORT_YES
+int decode_iso2ExiFragment(bitstream_t* stream, struct iso2EXIFragment* exiFrag);
+#endif /* DEPLOY_ISO2_CODEC_FRAGMENT */
+
+#endif /* DEPLOY_ISO2_CODEC */
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif

src/iso2/iso2EXIDatatypesEncoder.h

@@ -0,0 +1,68 @@
+/*
+ * Copyright (C) 2007-2018 Siemens AG
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published
+ * by the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+/*******************************************************************
+ *
+ * @author Daniel.Peintner.EXT@siemens.com
+ * @version 0.9.4 
+ * @contact Richard.Kuntschke@siemens.com
+ *
+ * <p>Code generated by EXIdizer</p>
+ * <p>Schema: V2G_CI_MsgDef.xsd</p>
+ *
+ *
+ ********************************************************************/
+
+
+
+/**
+ * \file 	EXIDatatypesEncoder.h
+ * \brief 	Encoder for datatype definitions
+ *
+ */
+
+#ifndef EXI_iso2_DATATYPES_ENCODER_H
+#define EXI_iso2_DATATYPES_ENCODER_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+
+#include "iso2EXIDatatypes.h"
+
+#if DEPLOY_ISO2_CODEC == SUPPORT_YES
+
+#include <stdint.h>
+
+#include "EXITypes.h"
+
+
+int encode_iso2ExiDocument(bitstream_t* stream, struct iso2EXIDocument* exiDoc);
+
+#if DEPLOY_ISO2_CODEC_FRAGMENT == SUPPORT_YES
+int encode_iso2ExiFragment(bitstream_t* stream, struct iso2EXIFragment* exiFrag);
+#endif /* DEPLOY_ISO2_CODEC_FRAGMENT */
+
+
+#endif /* DEPLOY_ISO2_CODEC */
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif