Need advice in nRF24l01+ programming (a rather unique project)

[swordz60]

Hi guys,
I'm currently working on a project involving 2 arduinos + 2 LCD screens + 2 GPS modules + 2 nRF24l01 modules. The idea is to create a warning system for trains. It's based on the speed of the locomotive and the speed of the last wagon. The point of that is knowing whether any of the wagons got decoupled (I know that this doesn't happen often, but I work for a railway company and it seemed like an original project for my bachelor's thesis).
I've got both arduinos up and running (they output speed, coordinates, visible satellites on the LCDs), but i can't seem to figure out how to transmit GPS data (in this case speed) from one arduino to the other via the nRF24l01+. I have succeeded flashing an LED and transmitting a text message so far.

TL;DR: How do I transfer real time data from one arduino to another using nRF24l01+?

I'd greatly appreciate your input and I'm sorry if I missed a post on a similar subject.
I'm a newbie in C# language, just a warning.


TRANSMITTER:

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Code C++ - [expand]
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#include <SoftwareSerial.h>
#include <TinyGPS.h>
#include <LiquidCrystal.h>
 
#include <SPI.h>
#include <nRF24L01.h>
#include <RF24.h>
 
int repeat = 0; 
 
LiquidCrystal lcd(7, 6, 5, 4, 3, 2); // Address used for the 16x2 LCD
RF24 radio(9, 10);   // 9 - CE, 10 - CSN
 
const byte rxAddr[6] = "12345"; 
TinyGPS gps;
SoftwareSerial ss(1, 0); // Define as software serial  mounted as tx and rx 
 
void setup()
{
  ss.begin(9600); // Serial communication at baud rate 9600 GPS to MCU
  lcd.begin(16,2);     
 
  radio.begin();  
  radio.setRetries(20, 10);  
  radio.openWritingPipe(rxAddr);  
  radio.stopListening();  
 
  
  for (int count=0; count <= 5; count++)
  {
    lcd.setCursor(0,0);
    lcd.print("Starting...");
    delay(800);
    lcd.clear();
    delay(800);
  }
 
  lcd.setCursor(0,0);
  lcd.print("Starting GPS..");
  lcd.setCursor(0,1);
  lcd.print("----------------");
  delay(10000);
  lcd.clear();
  
}
 
void loop()
{
  bool data = false;  
  unsigned long chars;    
  unsigned short sentences, failed;  
 
  // One second we parse GPS data and report some key values
  for (unsigned long start = millis(); millis() - start < 1000;) 
  {
    while (ss.available())
    {
      char c = ss.read();
       
      if (gps.encode(c))  
        data = true;  
    }
  }
 
  if (data)           
  {                             
    float flat, flon, speed;
    unsigned long age;        
    gps.f_get_position(&flat, &flon, &age);  
    
   
    if (repeat < 2) 
     { 
      lcd.setCursor(0,0);
      lcd.print("Coordinates:");
       lcd.setCursor(0,1);
       lcd.print(flat == TinyGPS::GPS_INVALID_F_ANGLE ? 0.0 : flat, 4); 
         lcd.setCursor(7,1);
         lcd.print(", ");
         lcd.setCursor(9,1);
         lcd.print(flon == TinyGPS::GPS_INVALID_F_ANGLE ? 0.0 : flon, 4); 
      delay(5000);
      lcd.clear();
      
      repeat++;
     }
    
    lcd.setCursor(0,0);
    lcd.print("Speed: ");
     lcd.setCursor(6,0);
     lcd.print(gps.f_speed_kmph() == TinyGPS::GPS_INVALID_F_SPEED ? 0 : gps.f_speed_kmph(), 1);
      lcd.setCursor(12,0);
      lcd.print("km/h");
        lcd.setCursor(0,1);
        lcd.print("Satellites: ");
         lcd.setCursor(11,1);
         lcd.print(gps.satellites() == TinyGPS::GPS_INVALID_SATELLITES ? 0 : gps.satellites());
 
      if (radio.available()) 
  {
    char rad_spd = (gps.f_speed_kmph() == TinyGPS::GPS_INVALID_F_SPEED ? 0 : gps.f_speed_kmph(), 1); 
    char rad_sats = gps.satellites() == TinyGPS::GPS_INVALID_SATELLITES ? 0 : gps.satellites();  
 
    radio.write(&rad_spd, sizeof(rad_spd));  
    radio.write(&rad_sats, sizeof(rad_sats)); 
    
  }
      
      if (repeat < 2)   
      {       
        delay(2000);
        lcd.clear();
        repeat++;
      }
    
  }
        
  else 
  {   
    gps.stats(&chars, &sentences, &failed);
    lcd.setCursor(0,0);
    lcd.print("Chars: ");
     lcd.setCursor(7,0);
     lcd.print(chars);
       lcd.setCursor(0,1);
       lcd.print("Sentences: ");
        lcd.setCursor(11,1);
        lcd.print(sentences);
     delay(1000);
     lcd.clear();
   }  
}

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RECEIVER:

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Code C++ - [expand]
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#include <SoftwareSerial.h>
#include <TinyGPS.h>
#include <Wire.h> 
#include <LiquidCrystal_I2C.h>
 
#include <SPI.h>
#include <nRF24L01.h>
#include <RF24.h>
 
int repeat = 0; 
 
LiquidCrystal_I2C lcd(0x27, 2, 1, 0, 4, 5, 6, 7, 3, POSITIVE); // Address used for the 20x4 LCD
RF24 radio(9, 10);   // 9 - CE, 10 - CSN
 
const byte rxAddr[6] = "12345";
TinyGPS gps;
SoftwareSerial ss(1, 0); // Define as software serial  mounted as tx and rx 
 
void setup()
{
  ss.begin(9600); // Serial communication at baud rate 9600 GPS to MCU
  lcd.begin(20,4);     
 
  radio.begin();  
  radio.openReadingPipe(0, rxAddr); 
  radio.startListening(); 
  
  for (int count=0; count <= 5; count++)
  {
    lcd.setCursor(0,0);
    lcd.print("Starting...");
    delay(800);
    lcd.clear();
    delay(800);
  }
 
  lcd.setCursor(0,0);
  lcd.print("Starting GPS..");
  lcd.setCursor(0,1);
  lcd.print("----------------");
  delay(10000);
  lcd.clear();  
}
 
void loop()
{
  bool data = false; 
  unsigned long chars;   
  unsigned short sentences, failed;  
 
  for (unsigned long start = millis(); millis() - start < 1000;) 
  {
    while (ss.available())
    {
      char c = ss.read();
       
      if (gps.encode(c))  
        data = true;  
    }
  }
 
  if (data)          
  {
                               
    float flat, flon, speed;
    unsigned long age;       
    gps.f_get_position(&flat, &flon, &age);  
    
   
    if (repeat < 2)
     { 
      lcd.setCursor(0,0);
      lcd.print("Coordinates:");
       lcd.setCursor(0,1);
       lcd.print(flat == TinyGPS::GPS_INVALID_F_ANGLE ? 0.0 : flat, 4); 
         lcd.setCursor(7,1);
         lcd.print(", ");
         lcd.setCursor(9,1);
         lcd.print(flon == TinyGPS::GPS_INVALID_F_ANGLE ? 0.0 : flon, 4); 
      delay(5000);
      lcd.clear();
      
      repeat++;
     }
    
       lcd.setCursor(0,0);
    lcd.print("Speed: ");
     lcd.setCursor(6,0);
     lcd.print(gps.f_speed_kmph() == TinyGPS::GPS_INVALID_F_SPEED ? 0 : gps.f_speed_kmph(), 1);
      lcd.setCursor(12,0);
      lcd.print("km/h");
        lcd.setCursor(0,1);
        lcd.print("Satellites: ");
         lcd.setCursor(11,1);
         lcd.print(gps.satellites() == TinyGPS::GPS_INVALID_SATELLITES ? 0 : gps.satellites());
 
      if (radio.available())  
    char rad_spd[32] = {0};  
    char rad_sats[32] = {0};  
    radio.read(&rad_spd, sizeof(rad_spd));  
    //radio.read(&rad_sats, sizeof(rad_sats));  
    
    lcd.setCursor(0,2);
    lcd.print(rad_spd);  
    //lcd.setCursor(0,3);
    //lcd.print(rad_sats); 
  }
      
      if (repeat < 2)     
      {       
        delay(2000);
        lcd.clear();
        repeat++;
      }
    
  }
 
   else 
   {   
    gps.stats(&chars, &sentences, &failed);
    lcd.setCursor(0,0);
    lcd.print("Chars: ");
     lcd.setCursor(7,0);
     lcd.print(chars);
       lcd.setCursor(0,1);
       lcd.print("Sentences: ");
        lcd.setCursor(11,1);
        lcd.print(sentences);
     delay(1000);
     lcd.clear();
 
   }  
}

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P.S. I use 2 LCDs for testing purposes, after the project is complete, there will be only 1 LCD left (the 20x4 one). I will also add some other functions later (comparation of the speeds, a buzzer to warn about the difference in speeds etc.)