Changed RX buffer to dynamic memory allocation to save RAM

Signed-off-by: Bill Porter <madsci1016@gmail.com>

Author: madsci1016

EasyTransfer/EasyTransfer.cpp

@@ -5,9 +5,12 @@
 
 //Captures address and size of struct
 void EasyTransfer::begin(uint8_t * ptr, uint8_t length, HardwareSerial *theSerial){
-address = ptr;
-size = length;
-_serial = theSerial;
+	address = ptr;
+	size = length;
+	_serial = theSerial;
+	
+	//dynamic creation of rx parsing buffer in RAM
+	rx_buffer = (uint8_t*) malloc(size);
 }
 
 //Sends out struct in binary, with header, length info and checksum
@@ -52,19 +55,19 @@ boolean EasyTransfer::receiveData(){
   //we get here if we already found the header bytes, the struct size matched what we know, and now we are byte aligned.
   if(rx_len != 0){
     while(_serial->available() && rx_array_inx <= rx_len){
-      rx_array[rx_array_inx++] = _serial->read();
+      rx_buffer[rx_array_inx++] = _serial->read();
     }
 
     if(rx_len == (rx_array_inx-1)){
       //seem to have got whole message
       //last uint8_t is CS
       calc_CS = rx_len;
       for (int i = 0; i<rx_len; i++){
-        calc_CS^=rx_array[i];
+        calc_CS^=rx_buffer[i];
       } 
 
-      if(calc_CS == rx_array[rx_array_inx-1]){//CS good
-        memcpy(address,&rx_array,size);
+      if(calc_CS == rx_buffer[rx_array_inx-1]){//CS good
+        memcpy(address,rx_buffer,size);
 		rx_len = 0;
 		rx_array_inx = 0;
 		return true;

EasyTransfer/EasyTransfer.h

@@ -52,9 +52,9 @@ HardwareSerial *_serial;
 //NewSoftSerial *_serial;
 uint8_t * address;  //address of struct
 uint8_t size;       //size of struct
-uint8_t rx_len;		//RX packet length according to the packet
-uint8_t rx_array[255]; //RX packet parsing buffer
+uint8_t * rx_buffer; //address for temporary storage and parsing buffer
 uint8_t rx_array_inx;  //index for RX parsing buffer
+uint8_t rx_len;		//RX packet length according to the packet
 uint8_t calc_CS;	   //calculated Chacksum
 };
 

EasyTransferI2C/EasyTransferI2C.cpp

@@ -5,9 +5,12 @@
 
 //Captures address and size of struct
 void EasyTransferI2C::begin(uint8_t * ptr, uint8_t length, TwoWire *theSerial){
-address = ptr;
-size = length;
-_serial = theSerial;
+	address = ptr;
+	size = length;
+	_serial = theSerial;
+
+	//dynamic creation of rx parsing buffer in RAM
+	rx_buffer = (uint8_t*) malloc(size);
 }
 
 //Sends out struct in binary, with header, length info and checksum
@@ -77,9 +80,9 @@ boolean EasyTransferI2C::receiveData(){
   if(rx_len != 0){
     while(_serial->available() && rx_array_inx <= rx_len){
 #if ARDUINO >= 100
-      rx_array[rx_array_inx++] = _serial->read();
+      rx_buffer[rx_array_inx++] = _serial->read();
 #else
-      rx_array[rx_array_inx++] = _serial->receive();
+      rx_buffer[rx_array_inx++] = _serial->receive();
 #endif
     }
 
@@ -88,11 +91,11 @@ boolean EasyTransferI2C::receiveData(){
       //last uint8_t is CS
       calc_CS = rx_len;
       for (int i = 0; i<rx_len; i++){
-        calc_CS^=rx_array[i];
+        calc_CS^=rx_buffer[i];
       } 
 
-      if(calc_CS == rx_array[rx_array_inx-1]){//CS good
-        memcpy(address,&rx_array,size);
+      if(calc_CS == rx_buffer[rx_array_inx-1]){//CS good
+        memcpy(address,rx_buffer,size);
 		rx_len = 0;
 		rx_array_inx = 0;
 		return true;

EasyTransferI2C/EasyTransferI2C.h

@@ -54,9 +54,9 @@ TwoWire *_serial;
 //NewSoftSerial *_serial;
 uint8_t * address;  //address of struct
 uint8_t size;       //size of struct
-uint8_t rx_len;		//RX packet length according to the packet
-uint8_t rx_array[255]; //RX packet parsing buffer
+uint8_t * rx_buffer; //address for temporary storage and parsing buffer
 uint8_t rx_array_inx;  //index for RX parsing buffer
+uint8_t rx_len;		//RX packet length according to the packet
 uint8_t calc_CS;	   //calculated Chacksum
 };
 

README.txt

@@ -1,5 +1,5 @@
 /******************************************************************
-*  EasyTransfer Arduino Library v2.0.1
+*  EasyTransfer Arduino Library v2.1
 *		details and example sketch: 
 *			http://www.billporter.info/easytransfer-arduino-library/
 *
@@ -30,6 +30,8 @@
 *           Added EasyTransferVirtualWire library for use with Virtual Wire and cheap radios.
 *   2.0.1
 *       VirtualWire version tested by garth@netram, bugs fixed. 
+*   2.1
+*	   Changes RX parsing buffer to dynamic allocation to conserve RAM.
 *
 *
 *  Limits of the Library

SoftEasyTransfer/SoftEasyTransfer.cpp

@@ -6,17 +6,23 @@
 #if ARDUINO > 22
 //Captures address and size of struct
 void SoftEasyTransfer::begin(uint8_t * ptr, uint8_t length, SoftwareSerial *theSerial){
-address = ptr;
-size = length;
-_serial = theSerial;
+	address = ptr;
+	size = length;
+	_serial = theSerial;
+
+	//dynamic creation of rx parsing buffer in RAM
+	rx_buffer = (uint8_t*) malloc(size);
 }
 
 #else
 //Captures address and size of struct
 void SoftEasyTransfer::begin(uint8_t * ptr, uint8_t length, NewSoftSerial *theSerial){
-address = ptr;
-size = length;
-_serial = theSerial;
+	address = ptr;
+	size = length;
+	_serial = theSerial;
+	
+	//dynamic creation of rx parsing buffer in RAM
+	rx_buffer = (uint8_t*) malloc(size);
 }
 
 #endif
@@ -80,19 +86,19 @@ boolean SoftEasyTransfer::receiveData(){
 
   if(rx_len != 0){
     while(_serial->available() && rx_array_inx <= rx_len){
-      rx_array[rx_array_inx++] = _serial->read();
+      rx_buffer[rx_array_inx++] = _serial->read();
     }
 
     if(rx_len == (rx_array_inx-1)){
       //seem to have got whole message
       //last uint8_t is CS
       calc_CS = rx_len;
       for (int i = 0; i<rx_len; i++){
-        calc_CS^=rx_array[i];
+        calc_CS^=rx_buffer[i];
       } 
 
-      if(calc_CS == rx_array[rx_array_inx-1]){//CS good
-        memcpy(address,&rx_array,size);
+      if(calc_CS == rx_buffer[rx_array_inx-1]){//CS good
+        memcpy(address,rx_buffer,size);
 		rx_len = 0;
 		rx_array_inx = 0;
 		return true;

SoftEasyTransfer/SoftEasyTransfer.h

@@ -66,9 +66,9 @@ NewSoftSerial *_serial;
 
 uint8_t * address;  //address of struct
 uint8_t size;       //size of struct
-uint8_t rx_len;		//RX packet length according to the packet
-uint8_t rx_array[255]; //RX packet parsing buffer
+uint8_t * rx_buffer; //address for temporary storage and parsing buffer
 uint8_t rx_array_inx;  //index for RX parsing buffer
+uint8_t rx_len;		//RX packet length according to the packet
 uint8_t calc_CS;	   //calculated Chacksum
 };