/*Receiver-leonardo

* Getting Started example sketch for nRF24L01+ radios

* This is an example of how to send data from one node to another using data structures

* Updated: Dec 2014 by TMRh20

*/

#include <SPI.h>

#include "RF24.h"

byte addresses[][6] = {"1Node","2Node"};

/****************** User Config ***************************/

/***      Set this radio as radio number 0 or 1         ***/

bool radioNumber = 0;

/* Hardware configuration: Set up nRF24L01 radio on SPI bus plus pins 7 & 8 */

RF24 radio(7,8);

/**********************************************************/

// Used to control whether this node is sending or receiving

bool role = 0;

struct dataStruct{

  unsigned long _micros;

  float value;

}myData;

void setup() {

  Serial.begin(9600);

  Serial.println(F("RF24/examples/GettingStarted_HandlingData"));

  Serial.println(F("*** PRESS 'T' to begin transmitting to the other node"));

  radio.begin();

  // Set the PA Level low to prevent power supply related issues since this is a

 // getting_started sketch, and the likelihood of close proximity of the devices. RF24_PA_MAX is default.

  radio.setPALevel(RF24_PA_LOW);

  // Open a writing and reading pipe on each radio, with opposite addresses

  if(radioNumber){

    radio.openWritingPipe(addresses[1]);

    radio.openReadingPipe(1,addresses[0]);

  }else{

    radio.openWritingPipe(addresses[0]);

    radio.openReadingPipe(1,addresses[1]);

  }

  myData.value = 1.22;

  // Start the radio listening for data

  radio.startListening();

}

void loop() {

/****************** Ping Out Role ***************************/  

if (role == 1)  {

    radio.stopListening();                                    // First, stop listening so we can talk.

    Serial.println(F("Now sending"));

    myData._micros = micros();

     if (!radio.write( &myData, sizeof(myData) )){

       Serial.println(F("failed"));

     }

    radio.startListening();                                    // Now, continue listening

    unsigned long started_waiting_at = micros();               // Set up a timeout period, get the current microseconds

    boolean timeout = false;                                   // Set up a variable to indicate if a response was received or not

    while ( ! radio.available() ){                             // While nothing is received

      if (micros() - started_waiting_at > 200000 ){            // If waited longer than 200ms, indicate timeout and exit while loop

          timeout = true;

          break;

      }      

    }

    if ( timeout ){                                             // Describe the results

        Serial.println(F("Failed, response timed out."));

    }else{

                                                                // Grab the response, compare, and send to debugging spew

        radio.read( &myData, sizeof(myData) );

        unsigned long time = micros();

        // Spew it

        Serial.print(F("Sent "));

        Serial.print(time);

        Serial.print(F(", Got response "));

        Serial.print(myData._micros);

        Serial.print(F(", Round-trip delay "));

        Serial.print(time-myData._micros);

        Serial.print(F(" microseconds Value "));

        Serial.println(myData.value);

    }

    // Try again 1s later

    delay(1000);

  }

/****************** Pong Back Role ***************************/

  if ( role == 0 )

  {

    if( radio.available()){

                                                           // Variable for the received timestamp

      while (radio.available()) {                          // While there is data ready

        radio.read( &myData, sizeof(myData) );             // Get the payload

      }

      radio.stopListening();                               // First, stop listening so we can talk  

      myData.value += 0.01;                                // Increment the float value

      radio.write( &myData, sizeof(myData) );              // Send the final one back.      

      radio.startListening();                              // Now, resume listening so we catch the next packets.     

      Serial.print(F("Sent response "));

      Serial.print(myData._micros);  

      Serial.print(F(" : "));

      Serial.println(myData.value);

   }

 }

/****************** Change Roles via Serial Commands ***************************/

  if ( Serial.available() )

  {

    char c = toupper(Serial.read());

    if ( c == 'T' && role == 0 ){      

      Serial.print(F("*** CHANGING TO TRANSMIT ROLE -- PRESS 'R' TO SWITCH BACK"));

      role = 1;                  // Become the primary transmitter (ping out)

   }else

    if ( c == 'R' && role == 1 ){

      Serial.println(F("*** CHANGING TO RECEIVE ROLE -- PRESS 'T' TO SWITCH BACK"));      

       role = 0;                // Become the primary receiver (pong back)

       radio.startListening();

    }

  }

} // Loop