/*
 * Author: Dennis Ruigrok and JP Meijers
 * Date: 2017-01-16
 *
 * This program is meant to be used with an Arduino UNO or NANO, conencted to an RNxx3 radio module.
 * It will most likely also work on other compatible Arduino or Arduino compatible boards,
 * like The Things Uno, but might need some slight modifications.
 *
 * Transmit a one byte packet via TTN, using confirmed messages,
 * waiting for an acknowledgement or a downlink message.
 *
 * CHECK THE RULES BEFORE USING THIS PROGRAM!
 *
 * CHANGE ADDRESS!
 * Change the device address, network (session) key, and app (session) key to the values
 * that are registered via the TTN dashboard.
 * The appropriate line is "myLora.initABP(XXX);" or "myLora.initOTAA(XXX);"
 * When using ABP, it is advised to enable "relax frame count".
 *
 * Connect the RN2xx3 as follows:
 * RN2xx3 -- Arduino
 * Uart TX -- 10
 * Uart RX -- 11
 * Reset -- 12
 * Vcc -- 3.3V
 * Gnd -- Gnd
 *
 * If you use an Arduino with a free hardware serial port, you can replace
 * the line "rn2xx3 myLora(mySerial);"
 * with     "rn2xx3 myLora(SerialX);"
 * where the parameter is the serial port the RN2xx3 is connected to.
 * Remember that the serial port should be initialised before calling initTTN().
 * For best performance the serial port should be set to 57600 baud, which is impossible with a software serial port.
 * If you use 57600 baud, you can remove the line "myLora.autobaud();".
 *
 */
#include <rn2xx3.h>
#include <SoftwareSerial.h>

SoftwareSerial mySerial(10, 11); // RX, TX

//create an instance of the rn2xx3 library,
//giving the software serial as port to use
rn2xx3 myLora(mySerial);

// the setup routine runs once when you press reset:
void setup()
{
  //output LED pin
  pinMode(13, OUTPUT);
  led_on();

  // Open serial communications and wait for port to open:
  Serial.begin(57600); //serial port to computer
  mySerial.begin(9600); //serial port to radio
  Serial.println("Startup");

  initialize_radio();

  //transmit a startup message
  myLora.tx("TTN Mapper on TTN Enschede node");

  led_off();
  delay(2000);
}

void initialize_radio()
{
  //reset rn2483
  pinMode(12, OUTPUT);
  digitalWrite(12, LOW);
  delay(500);
  digitalWrite(12, HIGH);

  delay(100); //wait for the RN2xx3's startup message
  mySerial.flush();

  //Autobaud the rn2483 module to 9600. The default would otherwise be 57600.
  myLora.autobaud();

  //check communication with radio
  String hweui = myLora.hweui();
  while(hweui.length() != 16)
  {
    Serial.println("Communication with RN2xx3 unsuccesful. Power cycle the board.");
    Serial.println(hweui);
    delay(10000);
    hweui = myLora.hweui();
  }

  //print out the HWEUI so that we can register it via ttnctl
  Serial.println("When using OTAA, register this DevEUI: ");
  Serial.println(myLora.hweui());
  Serial.println("RN2xx3 firmware version:");
  Serial.println(myLora.sysver());

  //configure your keys and join the network
  Serial.println("Trying to join TTN");
  bool join_result = false;

  //ABP: initABP(String addr, String AppSKey, String NwkSKey);
  join_result = myLora.initABP("02017201", "8D7FFEF938589D95AAD928C2E2E7E48F", "AE17E567AECC8787F749A62F5541D522");

  //OTAA: initOTAA(String AppEUI, String AppKey);
  //join_result = myLora.initOTAA("70B3D57ED00001A6", "A23C96EE13804963F8C2BD6285448198");

  while(!join_result)
  {
    Serial.println("Unable to join. Are your keys correct, and do you have TTN coverage?");
    delay(60000); //delay a minute before retry
    join_result = myLora.init();
  }
  Serial.println("Successfully joined TTN");

}

// the loop routine runs over and over again forever:
void loop()
{
    led_on();

    Serial.print("TXing");
    myLora.txCnf("!"); //one byte, blocking function

    switch(myLora.txCnf("!")) //one byte, blocking function
    {
      case RN2xx3_datatypes::TX_return_type::TX_FAIL:
      {
        Serial.println("TX unsuccessful or not acknowledged");
        break;
      }
      case RN2xx3_datatypes::TX_return_type::TX_SUCCESS:
      {
        Serial.println("TX successful and acknowledged");
        break;
      }
      case RN2xx3_datatypes::TX_return_type::TX_WITH_RX:
      {
        String received = myLora.getRx();
        received = rn2xx3_helper::base16decode(received);
        Serial.print("Received downlink: " + received);
        break;
      }
      default:
      {
        Serial.println("Unknown response from TX function");
      }
    }

    led_off();
    delay(10000);
}

void led_on()
{
  digitalWrite(13, 1);
}

void led_off()
{
  digitalWrite(13, 0);
}