Merge pull request #1 from kumy/master

communication via I2C

Author: Bill Porter

EasyTransferI2C/EasyTransferI2C.cpp

@@ -0,0 +1,85 @@
+#include "EasyTransferI2C.h"
+
+
+
+
+//Captures address and size of struct
+void EasyTransferI2C::begin(uint8_t * ptr, uint8_t length, TwoWire *theSerial){
+address = ptr;
+size = length;
+_serial = theSerial;
+}
+
+//Sends out struct in binary, with header, length info and checksum
+void EasyTransferI2C::sendData(uint8_t i2c_address){
+  uint8_t CS = size;
+  _serial->beginTransmission(i2c_address);
+  _serial->send(0x06);
+  _serial->send(0x85);
+  _serial->send(size);
+  for(int i = 0; i<size; i++){
+    CS^=*(address+i);
+    _serial->send(*(address+i));
+  }
+  _serial->send(CS);
+  _serial->endTransmission();
+}
+
+boolean EasyTransferI2C::receiveData(){
+  
+  //start off by looking for the header bytes. If they were already found in a previous call, skip it.
+  if(rx_len == 0){
+  //this size check may be redundant due to the size check below, but for now I'll leave it the way it is.
+    if(_serial->available() >= 3){
+	//this will block until a 0x06 is found or buffer size becomes less then 3.
+      while(_serial->receive() != 0x06) {
+		//This will trash any preamble junk in the serial buffer
+		//but we need to make sure there is enough in the buffer to process while we trash the rest
+		//if the buffer becomes too empty, we will escape and try again on the next call
+		if(_serial->available() < 3)
+			return false;
+		}
+      if (_serial->receive() == 0x85){
+        rx_len = _serial->receive();
+		//make sure the binary structs on both Arduinos are the same size.
+        if(rx_len != size){
+          rx_len = 0;
+          return false;
+        }
+      }
+    }
+  }
+  
+  //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->receive();
+    }
+    
+    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];
+      } 
+      
+      if(calc_CS == rx_array[rx_array_inx-1]){//CS good
+        memcpy(address,&rx_array,size);
+		rx_len = 0;
+		rx_array_inx = 0;
+		return true;
+		}
+		
+	  else{
+	  //failed checksum, need to clear this out anyway
+		rx_len = 0;
+		rx_array_inx = 0;
+		return false;
+	  }
+        
+    }
+  }
+  
+  return false;
+}

EasyTransferI2C/EasyTransferI2C.h

@@ -0,0 +1,65 @@
+/******************************************************************
+*  EasyTransferI2C Arduino Library 
+*		details and example sketch: 
+*			http://www.billporter.info/easytransfer-arduino-library/
+*
+*		Brought to you by:
+*              Mathieu Alorent
+*               Forked from
+*              Bill Porter
+*              www.billporter.info
+*
+*		See Readme for other info and version history
+*	
+*  
+*This program is free software: you can redistribute it and/or modify it under the terms of the GNU 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 General Public License for more details.
+<http://www.gnu.org/licenses/>
+*
+*This work is licensed under the Creative Commons Attribution-ShareAlike 3.0 Unported License. 
+*To view a copy of this license, visit http://creativecommons.org/licenses/by-sa/3.0/ or
+*send a letter to Creative Commons, 444 Castro Street, Suite 900, Mountain View, California, 94041, USA.
+******************************************************************/
+#ifndef EasyTransferI2C_h
+#define EasyTransferI2C_h
+
+
+//make it a little prettier on the front end. 
+#define details(name) (byte*)&name,sizeof(name)
+
+//Not neccessary, but just in case. 
+#if ARDUINO > 22
+#include "Arduino.h"
+#else
+#include "WProgram.h"
+#endif
+#include "HardwareSerial.h"
+//#include <NewSoftSerial.h>
+#include <math.h>
+#include <stdio.h>
+#include <stdint.h>
+#include <avr/io.h>
+#include <Wire.h>
+
+class EasyTransferI2C {
+public:
+void begin(uint8_t *, uint8_t, TwoWire *theSerial);
+void sendData(uint8_t address);
+boolean receiveData();
+private:
+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_array_inx;  //index for RX parsing buffer
+uint8_t calc_CS;	   //calculated Chacksum
+};
+
+
+
+#endif

EasyTransferI2C/Examples/EasyTransfer_RX_Example/EasyTransfer_RX_Example.pde

@@ -0,0 +1,45 @@
+#include <Wire.h>
+#include <EasyTransferI2C.h>
+
+//create object
+EasyTransferI2C ET; 
+
+struct RECEIVE_DATA_STRUCTURE{
+  //put your variable definitions here for the data you want to receive
+  //THIS MUST BE EXACTLY THE SAME ON THE OTHER ARDUINO
+  int blinks;
+  int pause;
+};
+
+//give a name to the group of data
+RECEIVE_DATA_STRUCTURE mydata;
+
+//define slave i2c address
+#define I2C_SLAVE_ADDRESS 9
+
+void setup(){
+  Wire.begin(I2C_SLAVE_ADDRESS);
+  //start the library, pass in the data details and the name of the serial port. Can be Serial, Serial1, Serial2, etc. 
+  ET.begin(details(mydata), &Wire);
+  //define handler function on receiving data
+  Wire.onReceive(receive);
+  
+  pinMode(13, OUTPUT);
+  
+}
+
+void loop() {}
+
+void receive(int numBytes){
+  //check and see if a data packet has come in. 
+  if(ET.receiveData()){
+    //this is how you access the variables. [name of the group].[variable name]
+    //since we have data, we will blink it out. 
+    for(int i = mydata.blinks; i>0; i--){
+      digitalWrite(13, HIGH);
+      delay(mydata.pause * 100);
+      digitalWrite(13, LOW);
+      delay(mydata.pause * 100);
+    }
+  }
+}

EasyTransferI2C/Examples/EasyTransfer_TX_Example/EasyTransfer_TX_Example.pde

@@ -0,0 +1,47 @@
+#include <Wire.h>
+#include <EasyTransferI2C.h>
+
+//create object
+EasyTransferI2C ET; 
+
+struct SEND_DATA_STRUCTURE{
+  //put your variable definitions here for the data you want to send
+  //THIS MUST BE EXACTLY THE SAME ON THE OTHER ARDUINO
+  int blinks;
+  int pause;
+};
+
+//give a name to the group of data
+SEND_DATA_STRUCTURE mydata;
+
+//define slave i2c address
+#define I2C_SLAVE_ADDRESS 9
+
+void setup(){
+  Wire.begin();
+  //start the library, pass in the data details and the name of the serial port. Can be Serial, Serial1, Serial2, etc.
+  ET.begin(details(mydata), &Wire);
+  
+  pinMode(13, OUTPUT);
+  
+  randomSeed(analogRead(0));
+  
+}
+
+void loop(){
+  //this is how you access the variables. [name of the group].[variable name]
+  mydata.blinks = random(5);
+  mydata.pause = random(5);
+  //send the data
+  ET.sendData(I2C_SLAVE_ADDRESS);
+  
+  //Just for fun, we will blink it out too
+   for(int i = mydata.blinks; i>0; i--){
+      digitalWrite(13, HIGH);
+      delay(mydata.pause * 100);
+      digitalWrite(13, LOW);
+      delay(mydata.pause * 100);
+    }
+  
+  delay(5000);
+}

EasyTransferI2C/keywords.txt

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+#######################################
+# Syntax Coloring Map EasyTransfer
+#######################################
+
+#######################################
+# Datatypes (KEYWORD1)
+#######################################
+
+EasyTransferI2C	KEYWORD1
+
+#######################################
+# Methods and Functions (KEYWORD2)
+#######################################
+Button	KEYWORD2
+sendData	KEYWORD2
+receiveData	KEYWORD2
+init	KEYWORD2
+
+
+#######################################
+# Constants (LITERAL1)
+#######################################
+details	LITERAL1