ve.diect with hex asnync messages

ignore async hex messeage on older devices
helgeerbe · Apr 17, 2023 · b8e06bf · b8e06bf
1 parent 40cee1f
commit b8e06bf
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Showing 2 changed files with 30 additions and 9 deletions.
diff --git a/lib/VeDirectFrameHandler/VeDirectFrameHandler.cpp b/lib/VeDirectFrameHandler/VeDirectFrameHandler.cpp
@@ -60,6 +60,7 @@ VeDirectFrameHandler::VeDirectFrameHandler() :
 	_state(IDLE),
 	_checksum(0),
 	_textPointer(0),
+	_hexSize(0),
 	_name(""),
 	_value(""),
 	_tmpFrame(),
@@ -99,7 +100,9 @@ void VeDirectFrameHandler::rxData(uint8_t inbyte)
 {
 	//if (mStop) return;
 	if ( (inbyte == ':') && (_state != CHECKSUM) ) {
-		_state = RECORD_HEX;
+		_prevState = _state; //hex frame can interrupt TEXT
+		_state = RECORD_HEX; 
+		_hexSize = 0;
 	}
 	if (_state != RECORD_HEX) {
 		_checksum += inbyte;
@@ -177,10 +180,7 @@ void VeDirectFrameHandler::rxData(uint8_t inbyte)
 		break;
 	}
 	case RECORD_HEX:
-		if (hexRxEvent(inbyte)) {
-			_checksum = 0;
-			_state = IDLE;
-		}
+		_state = hexRxEvent(inbyte);
 		break;
 	}
 }
@@ -279,10 +279,27 @@ void VeDirectFrameHandler::logE(const char * module, const char * error) {
 
 /*
  *	hexRxEvent
- *  This function included for continuity and possible future use.	
+ *  This function records hex answers or async messages	
  */
-bool VeDirectFrameHandler::hexRxEvent(uint8_t inbyte) {
-	return true;		// stubbed out for future
+int VeDirectFrameHandler::hexRxEvent(uint8_t inbyte) {
+	int ret=RECORD_HEX; // default - continue recording until end of frame
+
+	switch (inbyte) {
+	case '\n':
+		// restore previous state
+		ret=_prevState;
+		break;
+
+	default:
+		_hexSize++;
+		if (_hexSize>=VE_MAX_HEX_LEN) { // oops -buffer overflow - something went wrong, we abort
+			logE(MODULE,"hexRx buffer overflow - aborting read");
+			_hexSize=0;
+			ret=IDLE;
+		}
+	}
+
+	return ret;
 }
 
 bool VeDirectFrameHandler::isDataValid() {

diff --git a/lib/VeDirectFrameHandler/VeDirectFrameHandler.h b/lib/VeDirectFrameHandler/VeDirectFrameHandler.h
@@ -23,6 +23,8 @@
 
 #define VE_MAX_NAME_LEN 9   // VE.Direct Protocol: max name size is 9 including /0
 #define VE_MAX_VALUE_LEN 33 // VE.Direct Protocol: max value size is 33 including /0
+#define VE_MAX_HEX_LEN 100 // Maximum size of hex frame - max payload 34 byte (=68 char) + safe buffer
+
 
 typedef struct {
     uint16_t PID;                   // product id
@@ -69,12 +71,14 @@ class VeDirectFrameHandler {
     void textRxEvent(char *, char *);
     void frameEndEvent(bool);                 // copy temp struct to public struct
     void logE(const char *, const char *);    
-    bool hexRxEvent(uint8_t);
+    int hexRxEvent(uint8_t);
 
     //bool mStop;                               // not sure what Victron uses this for, not using
     int _state;                                // current state
+    int _prevState;                            // previous state
     uint8_t	_checksum;                         // checksum value
     char * _textPointer;                       // pointer to the private buffer we're writing to, name or value
+    int _hexSize;                               // length of hex buffer
     char _name[VE_MAX_VALUE_LEN];              // buffer for the field name
     char _value[VE_MAX_VALUE_LEN];             // buffer for the field value
     veStruct _tmpFrame{};                        // private struct for received name and value pairs