/*------------------------------------------------------------------
* GPS LORA SENDER 
* DUPE 9/2020 
* Receive GPS and send data via LORA/LORAWAN to file/display 
* HW: TTGO LORA ESP32, GPS MODUL VKEL > LoRaWAN CRO
* TX PIN 16 | RX PIN 17
* CO: https://github.com/matthijskooijman/arduino-lmic
* CO: https://github.com/mikalhart/TinyGPSPlus
--------------------------------------------------------------------*/

#include <lmic.h>
#include <hal/hal.h>
#include <TinyGPS++.h>
TinyGPSPlus gps;
#define PMTK_SET_NMEA_UPDATE_05HZ  "$PMTK220,2000*1C"
#define PMTK_SET_NMEA_UPDATE_1HZ  "$PMTK220,1000*1F"
#define PMTK_SET_NMEA_OUTPUT_RMCGGA "$PMTK314,0,1,0,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0*28"
#define RX1 16
#define TX1 17
HardwareSerial gpsSerial_1(1);
unsigned long last_update = 0;
uint8_t txBuffer[9];
uint32_t latitudeBinary, longitudeBinary;
uint16_t altitudeGps;
uint8_t hdopGps;
#ifdef COMPILE_REGRESSION_TEST
# warning "You must replace the values marked FILLMEIN with real values from the TTN control panel!"
# define FILLMEIN (#dont edit this, edit the lines that use FILLMEIN)
#endif
# define FILLMEIN 0
// LORA OTAA parameters
// This should also be in little endian format
static const u1_t PROGMEM APPEUI[8]={ };
void os_getArtEui (u1_t* buf) { memcpy_P(buf, APPEUI, 8);}
static const u1_t PROGMEM DEVEUI[8]={ };
void os_getDevEui (u1_t* buf) { memcpy_P(buf, DEVEUI, 8);}
// This key should be in big endian format
static const u1_t PROGMEM APPKEY[16] = { };
void os_getDevKey (u1_t* buf) {  memcpy_P(buf, APPKEY, 16);}
static osjob_t sendjob;
const unsigned TX_INTERVAL = 300;
// Pin mapping TTGO
const lmic_pinmap lmic_pins = {
    .nss = 18,
    .rxtx = LMIC_UNUSED_PIN,
    .rst = 14,
    .dio = {26, 33, 32},
};

unsigned char payload[15];
int counter = 0;
int vbatPort = 34;

void printHex2(unsigned v) {
    v &= 0xff;
    if (v < 16){
    Serial.print('0');
    Serial.print(v, HEX);
     }
}

void onEvent (ev_t ev) {
    Serial.print(os_getTime());
    Serial.print(": ");
    switch(ev) {
        case EV_SCAN_TIMEOUT:
            Serial.println(F("EV_SCAN_TIMEOUT"));
            break;
        case EV_BEACON_FOUND:
            Serial.println(F("EV_BEACON_FOUND"));
            break;
        case EV_BEACON_MISSED:
            Serial.println(F("EV_BEACON_MISSED"));
            break;
        case EV_BEACON_TRACKED:
            Serial.println(F("EV_BEACON_TRACKED"));
            break;
        case EV_JOINING:
            Serial.println(F("EV_JOINING"));
            break;
        case EV_JOINED:
            Serial.println(F("EV_JOINED"));
            {
              u4_t netid = 0;
              devaddr_t devaddr = 0;
              u1_t nwkKey[16];
              u1_t artKey[16];
              LMIC_getSessionKeys(&netid, &devaddr, nwkKey, artKey);
              Serial.print("netid: ");
              Serial.println(netid, DEC);
              Serial.print("devaddr: ");
              Serial.println(devaddr, HEX);
              Serial.print("AppSKey: ");
              for (size_t i=0; i<sizeof(artKey); ++i) {
                if (i != 0)
                  Serial.print("-");
                printHex2(artKey[i]);
              }
              Serial.println("");
              Serial.print("NwkSKey: ");
              for (size_t i=0; i<sizeof(nwkKey); ++i) {
                      if (i != 0)
                              Serial.print("-");
                      printHex2(nwkKey[i]);
              }
              Serial.println();
            }
            // Disable link check validation (automatically enabled
            // during join, but because slow data rates change max TX size, we don't use it in this example.
            LMIC_setLinkCheckMode(0);
            break;
        case EV_JOIN_FAILED:
            Serial.println(F("EV_JOIN_FAILED"));
            break;
        case EV_REJOIN_FAILED:
            Serial.println(F("EV_REJOIN_FAILED"));
            break;
        case EV_TXCOMPLETE:
            Serial.println(F("EV_TXCOMPLETE (includes waiting for RX windows)"));
            if (LMIC.txrxFlags & TXRX_ACK)
              Serial.println(F("Received ack"));
            if (LMIC.dataLen) {
              Serial.print(F("Received "));
              Serial.print(LMIC.dataLen);
              Serial.println(F(" bytes of payload"));
            }
            // Schedule next transmission
            os_setTimedCallback(&sendjob, os_getTime()+sec2osticks(TX_INTERVAL), do_send);
            break;
        case EV_LOST_TSYNC:
            Serial.println(F("EV_LOST_TSYNC"));
            break;
        case EV_RESET:
            Serial.println(F("EV_RESET"));
            break;
        case EV_RXCOMPLETE:
            // data received in ping slot
            Serial.println(F("EV_RXCOMPLETE"));
            break;
        case EV_LINK_DEAD:
            Serial.println(F("EV_LINK_DEAD"));
            break;
        case EV_LINK_ALIVE:
            Serial.println(F("EV_LINK_ALIVE"));
            break;
        case EV_TXSTART:
            Serial.println(F("EV_TXSTART"));
            break;
        default:
            Serial.print(F("Unknown event: "));
            Serial.println((unsigned) ev);
            break;
    }
}

void do_send(osjob_t* j){
 // Check if there is not a current TX/RX job running
     if (LMIC.opmode & OP_TXRXPEND) {
     Serial.println(F("OP_TXRXPEND, not sending"));
     } else {    
  /*
  int vbat = analogRead(vbatPort);
  Serial.print("Vbat = "); Serial.println(vbat); 
  char msg1[5];
  char msg2[5];
  char msg3[5];  
  char payload1[15];
  String payloads = "";
  payloads.concat(temp);
  payloads.concat(tlak);
  payloads.concat(vbat);
  payloads.toCharArray(payload1,11
  strcpy ((char*)payload, payload1); 
  Serial.print("Message: "); 
  Serial.println(payloads);
 */
 
 if (gps.encode(gpsSerial.read())) {
    displayGpsInfo();
    sendCoords();
  }
   if (gps.charsProcessed() < 10) {
   debugSerial.println(F("No GPS detected: check wiring."));
   }
 // Next TX is scheduled after TX_COMPLETE event.
  counter++;
  }
}

void sendCoords() {
  if (gps.location.age() < 1000 && (millis() - last_update) >= 1000) {
     buildPacket();
     Serial.print("Sending packet: ");
     Serial.println(counter);
     // prepare upstream data transmission at the next possible time 
     LMIC_setTxData2(1, txBuffer, sizeof(txBuffer)-1, 0);
     Serial.println("Data odeslana.");
     last_update = millis 
     delay(3000);
    }
    debugSerial.println("None packet TX");
}

void buildPacket() {
  latitudeBinary = ((gps.location.lat() + 90) / 180.0) * 16777215;
  longitudeBinary = ((gps.location.lng() + 180) / 360.0) * 16777215;

  txBuffer[0] = ( latitudeBinary >> 16 ) & 0xFF;
  txBuffer[1] = ( latitudeBinary >> 8 ) & 0xFF;
  txBuffer[2] = latitudeBinary & 0xFF;

  txBuffer[3] = ( longitudeBinary >> 16 ) & 0xFF;
  txBuffer[4] = ( longitudeBinary >> 8 ) & 0xFF;
  txBuffer[5] = longitudeBinary & 0xFF;

  altitudeGps = gps.altitude.meters();
  txBuffer[6] = ( altitudeGps >> 8 ) & 0xFF;
  txBuffer[7] = altitudeGps & 0xFF;

  hdopGps = gps.hdop.value()/10;
  txBuffer[8] = hdopGps & 0xFF;
}

void displayGpsInfo()
{
  debugSerial.print(F("Location: ")); 
  if (gps.location.isValid())
  {
    debugSerial.print(gps.location.lat(), 6);
    debugSerial.print(F(","));
    debugSerial.print(gps.location.lng(), 6);
  }
  else
  {
    debugSerial.print(F("GPS LOCATION INVALID"));
  }

  debugSerial.print(F("  Date/Time: "));
  if (gps.date.isValid())
  {
    debugSerial.print(gps.date.month());
    debugSerial.print(F("/"));
    debugSerial.print(gps.date.day());
    debugSerial.print(F("/"));
    debugSerial.print(gps.date.year());
  }
  else
  {
    debugSerial.print(F("GPS TIME INVALID"));
  }
  
  debugSerial.print(F(" "));
  if (gps.time.isValid())
  {
    if (gps.time.hour() < 10) debugSerial.print(F("0"));
    debugSerial.print(gps.time.hour());
    debugSerial.print(F(":"));
    if (gps.time.minute() < 10) debugSerial.print(F("0"));
    debugSerial.print(gps.time.minute());
    debugSerial.print(F(":"));
    if (gps.time.second() < 10) debugSerial.print(F("0"));
    debugSerial.print(gps.time.second());
    debugSerial.print(F("."));
    if (gps.time.centisecond() < 10) debugSerial.print(F("0"));
    debugSerial.print(gps.time.centisecond());
  }
  else
  {
    debugSerial.print(F("GPS INVALID"));
  }
  debugSerial.println();
}

void setup() {
    delay(5000);
    gpsSerial_1.begin(9600, SERIAL_8N1, RX1, TX1);
    gpsSerial.println(F(PMTK_SET_NMEA_UPDATE_1HZ));   // 1 Hz update rate
    while (! Serial);
    Serial.begin(9600);
    Serial.println(F("Starting"));    
       // LMIC init
    os_init();
    // Reset the MAC state. Session and pending data transfers will be discarded.
    LMIC_reset();
    // Start job (sending automatically starts OTAA too)
    do_send(&sendjob);
}

void loop() {
    os_runloop_once();
}