Arduino nRF to Serial

/*
 This program will TX all data received from the serial pins out to the nRF radio
 and sent out all the data received from the nRF to serial monitor/process the data

 For this code, I m using a GPS module Skylab SKM53 running at 9600bps

 Max nRF payload size = 30
 1st byte header :-
 8     : fragment/no fragment
 5 - 7 : number of fragments
 4     : unused
 1 - 3 : fragment sequence number

 Max buffer is 90 bytes

 Serial input pins RX 2 ,TX 3
 nRF pins CE 8, CSN, 9 MOSI 11, MIS0 12, SCK 13

 Date : 28/05/2013

 Written by Stanley Seow
 [email protected]
*/

#include <SoftwareSerial.h>
#include <SPI.h>
#include "nRF24L01.h"
#include "RF24.h"
#include "printf.h"


#define DATABUFFERSIZE 90
char dataBuffer[DATABUFFERSIZE];

byte dataBufferIndex = 0;
char startChar = '$';
char endChar = '\r';

SoftwareSerial mySerial(2,3);

// Set up nRF24L01 radio on SPI pin for CE, CSN
RF24 radio(8,9);

const uint64_t pipes[2] = { 0xDEDEDEDEE7ULL, 0xDEDEDEDEE9ULL };

// Defines for radio buffers
char RXPayload[33] = "";
char TXPayload[33] = "";
char STR1[33],STR2[33],STR3[33] = "";

int Sender, storeString = 0;

void setup(void)
{
  Serial.begin(115200);

  mySerial.begin(9600);
  delay(500);

  printf_begin();
  //printf("nRF Serial RX/TX\n\r");
  radio.begin();

  // Default radio setings
  radio.enableDynamicPayloads();
  radio.setDataRate(RF24_250KBPS);
  radio.setPALevel(RF24_PA_MAX);
  radio.setChannel(85);
  radio.setRetries(15,15);

  //check for which side is the sender ( receive data via softwareserial )
  if ( mySerial.available() ) {
         Sender = true;
  }

  if ( Sender ) {
    radio.openWritingPipe(pipes[0]);
    radio.openReadingPipe(1,pipes[1]);
  } else {
    // this side is the receiver connected to Serial Monitor
    radio.openWritingPipe(pipes[1]);
    radio.openReadingPipe(1,pipes[0]);
    radio.startListening();
  }

  //radio.printDetails();
  delay(500);

}

void loop(void) {

  if ( !Sender ) {
      nRF_Receive();
  } else {
      nRF_Sender();
  }
} // End of loop()


void nRF_Sender() {

  char dataBuffer2[DATABUFFERSIZE]="";
  int status = 0;

  if ( mySerial.overflow() ) {
       Serial.println("Overflow Checkpoint 1");
  }

  if (getSerialString() ) {
    //Serial.println("123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890");

    Serial.println(dataBuffer);

    //Serial.print("\t\t\t[");
    //Serial.print(strlen(dataBuffer));
    //Serial.println("]");
    // Make a copy of dataBuffer
    memcpy(&dataBuffer2, &dataBuffer,strlen(dataBuffer));


    fragmentPackets(dataBuffer2,strlen(dataBuffer2) );

  if ( mySerial.overflow() ) {
       Serial.println("Overflow Checkpoint 2");
  }

    sendPackets(STR1,STR2,STR3);

  if ( mySerial.overflow() ) {
       Serial.println("Overflow Checkpoint 3");
  }

 }
}


boolean getSerialString(){
    static byte dataBufferIndex = 0;
    while(mySerial.available()>0){
        char incomingbyte = mySerial.read();
        if(incomingbyte==startChar){
            dataBufferIndex = 0;  //Initialize our dataBufferIndex variable
            storeString = true;
        }
        if(storeString){
            //Let's check our index here, and abort if we're outside our buffer size
            //We use our define here so our buffer size can be easily modified
            if(dataBufferIndex==DATABUFFERSIZE){
                //Oops, our index is pointing to an array element outside our buffer.
                dataBufferIndex = 0;
                break;
            }
            if(incomingbyte==endChar){
                dataBuffer[dataBufferIndex] = 0; //null terminate the C string
                //Our data string is complete.  return true
                return true;
            }
            else{
                dataBuffer[dataBufferIndex++] = incomingbyte;
                dataBuffer[dataBufferIndex] = 0; //null terminate the C string
            }
        }
        else{
        }
    }
    //We've read in all the available Serial data, and don't have a valid string yet, so return false
    return false;
}


void fragmentPackets(char Buffer2[DATABUFFERSIZE],int len) {
// Two headers with 30 bytes payload
// 1st byte
//      8 bit - fragment, 1 or 0
// 7 to 5 bit - number of fragment, 111, 7 max fragment
//      4 bit - none
// 1 to 3 bit - fragment number, starting with 0 to 7, 000 to 111
//
// 2nd byte, reserved

/*
Serial.print("[");
Serial.print(len);
Serial.print("] ");
Serial.print("Buffer2:");
Serial.println(Buffer2);
*/

   STR1[0], STR2[0], STR3[0] = 0;

   if ( len < 31 ) {
     // for ( int i=0;i<len;i++) {
     //   STR1[i+2] = Buffer2[i]; }

     STR1[0] = B00010000;    // No fragmentation, 1 segment
     STR1[1] = 0xff;         // Reversed header
     STR1[2] = 0;            // null terminate string
     strcat(STR1,Buffer2);

   } else if ( len < 61 ) {
      //for ( int i=0;i<30;i++) {
      //  STR1[i+2] = Buffer2[i]; }

        STR1[0] = 0xA0; // fragmentation, 1010 0000, fragment bit, 2 fragments, fragment no. 0
        STR1[1] = 0xff; // Reverse header
        STR1[2] = 0;     // null terminate string
        strncat(STR1, Buffer2,30);

      //for ( int i=0;i<len-30;i++) {
      //  STR2[i+2] = Buffer2[i+30]; }

        STR2[0] = 0xA1; // fragmentation, 1010 0001, fragment bit, 2 fragments, fragment no. 1
        STR2[1] = 0xff; // Reverse header
        STR2[2] = 0;     // null terminate string, 32 bytes + 2 extra bytes
        strcat(STR2, &Buffer2[30]);    // Copy the balance of pointer address 30 and above

   } else if ( len < 91 )  {
      //for ( int i=0;i<30;i++) {
      //  STR1[i+2] = Buffer2[i]; }

        STR1[0] = 0xB0; // fragmentation, 1011 0000, fragment bit, 3 fragments, fragment no. 0
        STR1[1] = 0xff; // Reverse header
        STR1[2] = 0;     // null terminate string
        strncat(STR1, Buffer2,30);    // Copy the 1st 30 bytes to STR1

      //for ( int i=0;i<30;i++) {
      //  STR2[i+2] = Buffer2[i+30]; }

        STR2[0] = 0xB1; // fragmentation, 1011 0001, fragment bit, 3 fragments, fragment no. 1
        STR2[1] = 0xff; // Reverse header
        STR2[2] = 0;     // null terminate string
        strncat(STR2, &Buffer2[30],30);  // Copy the next 30 bytes to STR2

      //for ( int i=0;i<len-60;i++) {
      //  STR3[i+2] = Buffer2[i+60]; }

        STR3[0] = 0xB2; // fragmentation, 1011 0011, fragment bit, 3 fragments, fragment no. 2
        STR3[1] = 0xff; // Reverse header
        STR3[2] = 0;     // null terminate string
        strcat(STR3, &Buffer2[60]);

      } else {
      // payload > 90 bytes, discard or add more fragments
   } // end if

/*
Serial.print("\tSTR1:");
Serial.println(STR1);
Serial.print("\tSTR2:");
Serial.println(STR2);
Serial.print("\tSTR3:");
Serial.println(STR3);
*/
}  // end fragmentPackets


void sendPackets(char TMP1[33], char TMP2[33], char TMP3[33]) {

//Serial.print("\tTMP1:");
//Serial.println(TMP1);
//Serial.print("\tTMP2:");
//Serial.println(TMP2);
//Serial.print("\tTMP3:");
//Serial.println(TMP3);

  int status = (STR1[0] & B00110000)>>4;

  radio.stopListening();

  // Mask the 1st Byte, bits 5 & 6 and shift 4 places to right
  // Return 0, 2 or 3 fragments

  switch (status) {
    case 1:
        if ( !radio.write(TMP1,strlen(TMP1) ) ) {
          //Serial.println("\tNRF error TMP1, frag=0");
         }
        //delay(1);
      break;
    case 2:
        if ( !radio.write(TMP1,strlen(TMP1) ) ) {
            //Serial.println("\tNRF error TMP1, frag=1");
         }
        //delay(1);
        if ( !radio.write(TMP2,strlen(TMP2) ) ) {
           //Serial.println("\tNRF error TMP2, frag=1");
         }
        //delay(1);
      break;
    case 3:
        if ( !radio.write(TMP1,strlen(TMP1) ) ) {
            //Serial.println("\tNRF error TMP1, frag=2");
         }
        //delay(1);
        if ( !radio.write(TMP2,strlen(TMP2) ) ) {
            //Serial.println("\tNRF error TMP2, frag=2");
         }
        //delay(1);
        if ( !radio.write(TMP3,strlen(TMP3) ) ) {
            //Serial.println("\tNRF error TMP3, frag=2");
         }
        //delay(1);
       break;
    } // switch/case  end

    radio.startListening();

} // nrf_Send end



// Receive payload from nRF at remote end

void nRF_Receive(){

  uint8_t len=0, mergeA=0, mergeB=0, Head1 = 0;
  // Call startlistening everytime here

  if ( radio.available() ) {
    len = radio.getDynamicPayloadSize();
    radio.read( &RXPayload, len );

    RXPayload[len] = 0;

//Serial.print("nRF RXPayload:");
//Serial.print(RXPayload);
//Serial.print(" [");
//Serial.print(len);
//Serial.print("]");
Head1 = RXPayload[0] & 0xff;
//Serial.print(" Head1:");
//Serial.println(Head1,HEX);

    if ( Head1 == 0x00 ) {
     // No fragment, strip off first 2 header bytes
        STR1[0] = 0;
        memcpy(&STR1,&RXPayload[2],len-2 );
        STR1[len-2]=0;

        sprintf(dataBuffer,"%s",STR1);
    } else if ( Head1 == 0xA0 ) {
     // Fragment packets, with 2 fragments
        STR1[0] = 0;
        memcpy(&STR1, &RXPayload[2],30);

        //for ( int i=0;i<30;i++ ) {
        //  STR1[i] = RXPayload[i+2]; }
        STR1[30]=0;
        mergeA=0;
//Serial.print("STR1:");
//Serial.println(STR1);
        sprintf(dataBuffer,"%s",STR1);
   } else if ( Head1 == 0xA1 ) {
     // Fragment packets, with 2 fragments
        STR2[0] = 0;
        memcpy(&STR2, &RXPayload[2],len-2 );

        STR2[len-2]=0;
//Serial.print("STR2:");
//Serial.println(STR2);
        mergeA=1;
        sprintf(dataBuffer,"%s%s",dataBuffer,STR2);
    } else if ( Head1 == 0xB0 ) {
     // Fragment packets, with 3 fragments
         STR1[0] = 0;
         memcpy(&STR1, &RXPayload[2],30);

         STR1[30]=0;
         mergeB=0;
//Serial.print("STR1:");
//Serial.println(STR1);

    } else if ( Head1 == 0xB1 ) {
     // Fragment packets, with 3 fragments
        STR2[0] = 0;
        memcpy(&STR2, &RXPayload[2],30);

        STR2[30]=0;
        mergeB=0;
//Serial.print("STR2:");
//Serial.println(STR2);
        sprintf(dataBuffer,"%s%s",STR1,STR2);

    } else if ( Head1 == 0xB2 ) {
     // Fragment packets, with 3 fragments
         STR3[0] = 0;
        memcpy(&STR3, &RXPayload[2],len-2 );

        STR2[len-2]=0;
        mergeB=1;
//Serial.print("STR3:");
//Serial.println(STR3);
        sprintf(dataBuffer,"%s%s",dataBuffer,STR3);

    } else {
      // Invalid payload or error payloads
      //Serial.println("Invalid Packets");
      dataBuffer[0] = 0;
    }
} // end radio.available if


    // Print merge payload to Serial Monitor
    if ( (dataBuffer[0] == '$') && ( mergeA || mergeB) ) {
//Serial.print("nRF RECV     :");
      Serial.println(dataBuffer);
//Serial.print(" [");
//Serial.print(strlen(dataBuffer));
//Serial.println("]");
    // Reset the merge
    mergeA, mergeB = 0;
    }

}