Merge branch 'Feature_Add_Callback_for_Datastream_Messages' of https:…

…//github.com/Tympan/Tympan_Library into Feature_Add_Callback_for_Datastream_Messages
Tympan · Jun 15, 2022 · 69ddd94 · 69ddd94
2 parents 9b6ebeb + 9751b9c
commit 69ddd94
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diff --git a/src/SerialManagerBase.cpp b/src/SerialManagerBase.cpp
@@ -48,7 +48,7 @@ void SerialManagerBase::respondToByte(char c) {
     case STREAM_LENGTH:
       if (c == DATASTREAM_SEPARATOR) {
         // Get the datastream length:
-        stream_length = *((int*)(stream_data));
+        memcpy(&stream_length, &stream_data[0], 4);
         serial_read_state = STREAM_DATA;
         stream_chars_received = 0;
         Serial.print("SerialManagerBase: RespondToByte: Stream length = ");

diff --git a/src/SerialManagerBase.h b/src/SerialManagerBase.h
@@ -75,9 +75,39 @@
 			 inadvertently invoking these modes, never send characters such as 0x02, 0x03, 0x04.
 			 In fact, you should generally avoid any non-printable character or you risk seeing
 			 unexpected behavior.
-	
-	License: MIT License.  Use at your own risk.  Have fun!
 
+			 Datastreams expect the following message protocol.  Note that the message length and payload are sent as little endian (LSB, MSB):
+			 	1.	DATASTREAM_START_CHAR 	(0x02)
+				2.	Message Length (int32): number of bytes including parts-4 thru part-6
+				3.	DATASTREAM_SEPARATOR 	(0x03)
+				4.	Message Type (char): Avoid using the special characters 0x03 or 0x04.  (if set to ‘test’, it will print out the payload as an int, then a float)
+				5.	DATASTREAM_SEPARATOR 	(0x03)
+				6.	Payload
+				7.	DATASTREAM_END_CHAR 	(0x04)
+
+			Use RealTerm to send a 'test' message: 
+			0x02 0x0D 0x00 0x00 0x00 0x03 0x74 0x65 0x73 0x74 0x03 0xD2 0x02 0x96 0x49 0xD2 0x02 0x96 0x49 0x04
+				1. DATASTREAM_START_CHAR 	(0x02)
+				2.	Message Length (int32): (0x000D) = 13 
+				3.	DATASTREAM_SEPARATOR 	(0x03)
+				4.	Message Type (char): 	(0x74657374) = 'test'
+				5.	DATASTREAM_SEPARATOR 	(0x03)
+				6.	Payload					(0x499602D2, 0x499602D2) = [1234567890, 1234567890]
+				7.	DATASTREAM_END_CHAR 	(0x04)
+
+			- Expected output
+				-  SerialManagerBase: RespondToByte: Start data stream.
+                - SerialManagerBase: RespondToByte: Stream length = 13
+                - SerialManagerBase: RespondToByte: Time to process stream!
+            	- Stream is of type 'test'.
+                - int is 1234567890
+                - float is 1228890.25
+
+			To register a callback when a datastream message is received, use setDataStreamCallback() and set a unique message type (i.e. not 'gha', 'dsl', afc', or 'test'):
+ 			- `serialManager.setDataStreamCallback(&dataStreamCallback);`
+			- `void dataStreamCallback(char* payload_p, String *msgType_p, int numBytes)`
+
+	License: MIT License.  Use at your own risk.  Have fun!
 */