Work on decoding using structs

TODO

@@ -2,3 +2,7 @@
 
 * Consider support for upper/lower case MAC address and optionaly ":"
 * Scanning - list devices publishing, should be able to get list even without knowing MAC / Encryption key
+* Struct vs Manual
+    * Sh3dNg version and examples uses structs to get data - seems to work
+    * Example generated uses manually managing a string
+    * Reconsider what is best and use

src/VictronBLE.cpp

@@ -213,6 +213,8 @@ void VictronBLE::processDevice(BLEAdvertisedDevice advertisedDevice) {
         return;
     }
 
+    // XXX Use struct like code in Sh3dNg
+
     // Check if it's Victron (manufacturer ID 0x02E1)
     uint16_t mfgId = (uint8_t)mfgData[1] << 8 | (uint8_t)mfgData[0];
     if (mfgId != VICTRON_MANUFACTURER_ID) {
@@ -236,9 +238,11 @@ bool VictronBLE::parseAdvertisement(const uint8_t* manufacturerData, size_t len,
                                     const String& macAddress) {
     auto it = devices.find(macAddress);
     if (it == devices.end()) {
+        debugPrint("parseAdvertisement: Device not found");
         return false;
     }
 
+    // XXX Work out second?
     DeviceInfo* deviceInfo = it->second;
 
     if (len < 6) {
@@ -246,18 +250,29 @@ bool VictronBLE::parseAdvertisement(const uint8_t* manufacturerData, size_t len,
         return false;
     }
 
+    // XXX map to struct - NOTE: Check size first (exact? or bigger?)
+    victronManufacturerData * vicData=(victronManufacturerData *)manufacturerData;
+    debugPrint("VendorID" + String(vicData->vendorID));
+    debugPrint("Record Type" + String(vicData->victronRecordType));
+
     // Structure: [MfgID(2)] [DeviceType(1)] [IV(2)] [EncryptedData(n)]
-    uint8_t deviceType = manufacturerData[2];
+    // XXX This is actually 4 - Struct would help - it was 2
+    uint8_t deviceType = manufacturerData[4];
 
     // Extract IV (initialization vector) - bytes 3-4, little-endian
+    // XXX These look wrong
     uint8_t iv[16] = {0};
     iv[0] = manufacturerData[3];
     iv[1] = manufacturerData[4];
     // Rest of IV is zero-padded
 
     // Encrypted data starts at byte 5
-    const uint8_t* encryptedData = manufacturerData + 5;
+    // const uint8_t* encryptedData = manufacturerData + 5;
-    size_t encryptedLen = len - 5;
+    // size_t encryptedLen = len - 5;
+
+    // XXX Experiment
+    const uint8_t* encryptedData = vicData->victronEncryptedData;
+    size_t encryptedLen = sizeof(vicData->victronEncryptedData);
 
     if (debugEnabled) {
         debugPrintHex("Encrypted data", encryptedData, encryptedLen);

src/VictronBLE.h

@@ -1,9 +1,9 @@
 /**
  * VictronBLE - ESP32 library for Victron Energy BLE devices
- * 
+ *
  * Based on Victron's official BLE Advertising protocol documentation
  * Inspired by hoberman's examples and keshavdv's Python library
- * 
+ *
  * Copyright (c) 2025 Scott Penrose
  * License: MIT
  */
@@ -53,6 +53,39 @@ enum SolarChargerState {
     CHARGER_EXTERNAL_CONTROL = 252
 };
 
+// XXX HARD Core structs
+//  Used for decoding
+// But then data is put into specific device structs
+// Which means a lot of overlap - reconsider...
+//  NOTE: c struct vs classes
+
+// Must use the "packed" attribute to make sure the compiler doesn't add any padding to deal with
+// word alignment.
+typedef struct {
+  uint8_t deviceState;
+  uint8_t errorCode;
+  int16_t batteryVoltage;
+  int16_t batteryCurrent;
+  uint16_t todayYield;
+  uint16_t inputPower;
+  uint8_t outputCurrentLo;  // Low 8 bits of output current (in 0.1 Amp increments)
+  uint8_t outputCurrentHi;  // High 1 bit of ourput current (must mask off unused bits)
+  uint8_t unused[4];
+} __attribute__((packed)) victronPanelData; // XXX Specific type -
+
+typedef struct {
+  uint16_t vendorID;                 // vendor ID
+  uint8_t beaconType;                // Should be 0x10 (Product Advertisement) for the packets we want
+  uint8_t unknownData1[3];           // Unknown data
+  uint8_t victronRecordType;         // Should be 0x01 (Solar Charger) for the packets we want
+  uint16_t nonceDataCounter;         // Nonce
+  uint8_t encryptKeyMatch;           // Should match pre-shared encryption key byte 0
+  uint8_t victronEncryptedData[21];  // (31 bytes max per BLE spec - size of previous elements)
+  uint8_t nullPad;                   // extra byte because toCharArray() adds a \0 byte.
+} __attribute__((packed)) victronManufacturerData;
+
+// XXX End of new bit above
+
 // Base structure for all device data
 struct VictronDeviceData {
     String deviceName;
@@ -61,8 +94,8 @@ struct VictronDeviceData {
     int8_t rssi;
     uint32_t lastUpdate;
     bool dataValid;
-    
+
-    VictronDeviceData() : deviceType(DEVICE_TYPE_UNKNOWN), rssi(-100), 
+    VictronDeviceData() : deviceType(DEVICE_TYPE_UNKNOWN), rssi(-100),
                           lastUpdate(0), dataValid(false) {}
 };
 
@@ -75,8 +108,8 @@ struct SolarChargerData : public VictronDeviceData {
     float panelPower;          // W
     uint16_t yieldToday;       // Wh
     float loadCurrent;         // A
-    
+
-    SolarChargerData() : chargeState(CHARGER_OFF), batteryVoltage(0), 
+    SolarChargerData() : chargeState(CHARGER_OFF), batteryVoltage(0),
                          batteryCurrent(0), panelVoltage(0), panelPower(0),
                          yieldToday(0), loadCurrent(0) {
         deviceType = DEVICE_TYPE_SOLAR_CHARGER;
@@ -97,8 +130,8 @@ struct BatteryMonitorData : public VictronDeviceData {
     bool alarmLowSOC;
     bool alarmLowTemperature;
     bool alarmHighTemperature;
-    
+
-    BatteryMonitorData() : voltage(0), current(0), temperature(0), 
+    BatteryMonitorData() : voltage(0), current(0), temperature(0),
                            auxVoltage(0), remainingMinutes(0), consumedAh(0),
                            soc(0), alarmLowVoltage(false), alarmHighVoltage(false),
                            alarmLowSOC(false), alarmLowTemperature(false),
@@ -117,7 +150,7 @@ struct InverterData : public VictronDeviceData {
     bool alarmLowVoltage;
     bool alarmHighTemperature;
     bool alarmOverload;
-    
+
     InverterData() : batteryVoltage(0), batteryCurrent(0), acPower(0),
                      state(0), alarmHighVoltage(false), alarmLowVoltage(false),
                      alarmHighTemperature(false), alarmOverload(false) {
@@ -132,7 +165,7 @@ struct DCDCConverterData : public VictronDeviceData {
     float outputCurrent;       // A
     uint8_t chargeState;
     uint8_t errorCode;
-    
+
     DCDCConverterData() : inputVoltage(0), outputVoltage(0), outputCurrent(0),
                           chargeState(0), errorCode(0) {
         deviceType = DEVICE_TYPE_DCDC_CONVERTER;
@@ -158,7 +191,7 @@ struct VictronDeviceConfig {
     String macAddress;
     String encryptionKey;  // 32 character hex string
     VictronDeviceType expectedType;
-    
+
     VictronDeviceConfig() : expectedType(DEVICE_TYPE_UNKNOWN) {}
     VictronDeviceConfig(String n, String mac, String key, VictronDeviceType type = DEVICE_TYPE_UNKNOWN)
         : name(n), macAddress(mac), encryptionKey(key), expectedType(type) {}
@@ -169,50 +202,50 @@ class VictronBLE {
 public:
     VictronBLE();
     ~VictronBLE();
-    
+
     // Initialize BLE and start scanning
     bool begin(uint32_t scanDuration = 5);
-    
+
     // Add a device to monitor
     bool addDevice(const VictronDeviceConfig& config);
-    bool addDevice(String name, String macAddress, String encryptionKey, 
+    bool addDevice(String name, String macAddress, String encryptionKey,
                    VictronDeviceType expectedType = DEVICE_TYPE_UNKNOWN);
-    
+
     // Remove a device
     void removeDevice(String macAddress);
-    
+
     // Get device count
     size_t getDeviceCount() const { return devices.size(); }
-    
+
     // Set callback for data updates
     void setCallback(VictronDeviceCallback* cb) { callback = cb; }
-    
+
     // Process scanning (call in loop())
     void loop();
-    
+
     // Get latest data for a device
     bool getSolarChargerData(String macAddress, SolarChargerData& data);
     bool getBatteryMonitorData(String macAddress, BatteryMonitorData& data);
     bool getInverterData(String macAddress, InverterData& data);
     bool getDCDCConverterData(String macAddress, DCDCConverterData& data);
-    
+
     // Get all devices of a specific type
     std::vector<String> getDevicesByType(VictronDeviceType type);
-    
+
     // Enable/disable debug output
     void setDebug(bool enable) { debugEnabled = enable; }
-    
+
     // Get last error message
     String getLastError() const { return lastError; }
-    
+
 private:
     friend class VictronBLEAdvertisedDeviceCallbacks;
-    
+
     struct DeviceInfo {
         VictronDeviceConfig config;
         VictronDeviceData* data;
         uint8_t encryptionKeyBytes[16];
-        
+
         DeviceInfo() : data(nullptr) {
             memset(encryptionKeyBytes, 0, 16);
         }
@@ -220,7 +253,7 @@ private:
             if (data) delete data;
         }
     };
-    
+
     std::map<String, DeviceInfo*> devices;
     BLEScan* pBLEScan;
     VictronDeviceCallback* callback;
@@ -228,25 +261,25 @@ private:
     String lastError;
     uint32_t scanDuration;
     bool initialized;
-    
+
     // Internal methods
     bool hexStringToBytes(const String& hex, uint8_t* bytes, size_t len);
-    bool decryptAdvertisement(const uint8_t* encrypted, size_t encLen, 
+    bool decryptAdvertisement(const uint8_t* encrypted, size_t encLen,
                               const uint8_t* key, const uint8_t* iv,
                               uint8_t* decrypted);
     bool parseAdvertisement(const uint8_t* manufacturerData, size_t len,
                             const String& macAddress);
     void processDevice(BLEAdvertisedDevice advertisedDevice);
-    
+
     VictronDeviceData* createDeviceData(VictronDeviceType type);
     bool parseSolarCharger(const uint8_t* data, size_t len, SolarChargerData& result);
     bool parseBatteryMonitor(const uint8_t* data, size_t len, BatteryMonitorData& result);
     bool parseInverter(const uint8_t* data, size_t len, InverterData& result);
     bool parseDCDCConverter(const uint8_t* data, size_t len, DCDCConverterData& result);
-    
+
     void debugPrint(const String& message);
     void debugPrintHex(const char* label, const uint8_t* data, size_t len);
-    
+
     String macAddressToString(BLEAddress address);
     String normalizeMAC(String mac);
 };
@@ -256,7 +289,7 @@ class VictronBLEAdvertisedDeviceCallbacks: public BLEAdvertisedDeviceCallbacks {
 public:
     VictronBLEAdvertisedDeviceCallbacks(VictronBLE* parent) : victronBLE(parent) {}
     void onResult(BLEAdvertisedDevice advertisedDevice) override;
-    
+
 private:
     VictronBLE* victronBLE;
 };