/*
* Getting Started example sketch for nRF24L01+ radios
* This is a very basic example of how to send data from one node to another
* Updated: Dec 2014 by TMRh20
* 
* Edited to add demo screen code from Adafruit.
* 
*/

#include <SPI.h>

/* for nRF24L01+ Modules */
#include "DigitalIO.h"
#include "RF24.h"

/* for OLED Screen */
#include <Wire.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>

// If using software SPI (the default case):
#define OLED_MOSI   18
#define OLED_CLK   17
#define OLED_DC    16
#define OLED_CS    14
#define OLED_RESET 15
Adafruit_SSD1306 display(OLED_MOSI, OLED_CLK, OLED_DC, OLED_RESET, OLED_CS);

/* Uncomment this block to use hardware SPI
#define OLED_DC     6
#define OLED_CS     7
#define OLED_RESET  8
Adafruit_SSD1306 display(OLED_DC, OLED_RESET, OLED_CS);
*/

#if (SSD1306_LCDHEIGHT != 32)
#error("Height incorrect, please fix Adafruit_SSD1306.h!");
#endif



/****************** User Config ***************************/
/***      Set this radio as radio number 0 or 1         ***/
bool radioNumber = 1;

/* Hardware configuration: Set up nRF24L01 radio on SPI bus plus pins 7 & 8 */
RF24 radio(6,5);
/**********************************************************/

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

// store current heading
int currentHeading = 0;

void setup() {
  Serial.begin(115200);
  Serial.println(F("GPS Screen Receiver"));
  
  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]);
  }
  
  // Start the radio listening for data
  radio.startListening();

/* Screen Setup */

  // by default, we'll generate the high voltage from the 3.3v line internally! (neat!)
  display.begin(SSD1306_SWITCHCAPVCC);
  // init done

  display.clearDisplay();

}

void loop() {
  
    int degrees_;

    // if there is new information
    if(radio.available()){
                                                                    // Variable for the received timestamp
      while (radio.available()) {                                   // While there is data ready
        radio.read( &degrees_, sizeof(int) );                       // Get the payload
      }

      // let the transmitter know we got it
      radio.stopListening();                                        // First, stop listening so we can talk   
      radio.write( &degrees_, sizeof(unsigned long) );              // Send the final one back.      
      radio.startListening();                                       // Now, resume listening so we catch the next packets.     
      Serial.print(F("Sent response "));
      Serial.println(degrees_);

      // check to see if it is different than what we already have
      if(currentHeading != degrees_) {

        currentHeading = degrees_;
        // if so then update the display
        display.clearDisplay();
        // text display tests
        display.setTextSize(2);
        display.setTextColor(WHITE);
        display.setCursor(0,0);
        display.print(currentHeading);
        display.println("degrees");
        display.display();
    }
   
   }

} // Loop