Pet Locator Powered by Spresense GPS

/* include the GNSS library */
#include <GNSS.h>
#include<math.h>

#include <SoftwareSerial.h> 
//software serial is for connecting GPRS module
SoftwareSerial GPRS(26, 27); // RX, TX

#define RESTART_CYCLE       (60 * 5)
static SpGnss Gnss;                   /**< SpGnss object */


//Ubidots credentials
#define TOKEN "A1E-wy1sLSSOhc2uhB1L31oL7hL1f8v1DE"  // Remplace it with your token

#define ID1 "5c6b52fe5916361009c83050" // variable ID for flag
#define ID2 "5c6ad8eec03f970ee849e608" // for variable lat
#define ID3 "5c6ad8d8c03f970e872bc451" // for variable long


char latoutput[15];
char longoutput[15];

void setup() {
 
  /* For serial debugging */
  Serial.begin(115200);
  // Serial com for communicating with GPRS Modulr
  GPRS.begin(19200);
  /* Wait HW initialization done. */
  sleep(3);
  /* Set Debug mode to Info */
  Gnss.setDebugMode(PrintInfo);

  int result;

  /* Activate GNSS device */
  result = Gnss.begin();

  if (result == 0)
  {
   //configuring gprs type
   Gnss.select(GPS);
   Gnss.select(GLONASS);
   Gnss.select(QZ_L1CA);
   /* Start positioning */
   result = Gnss.start(COLD_START);
   if (result != 0)
    {
       exit(0);
    }
    
  }
  
}

/**
 * @brief %Print position information.
 */
static void print_pos(SpNavData *pNavData)
{
  if (pNavData->posFixMode == FixInvalid)
  {
    Serial.print("No-Fix, ");
  }
  else
  {
    Serial.print("Fix, ");
  }
  if (pNavData->posDataExist == 0)
  {
    Serial.print("No Position");
  }
  else
  {
    float longi = pNavData->longitude;
    float lati = pNavData->latitude;
    ftoa(lati,latoutput,6);
    ftoa(longi,longoutput,6);
    Serial.print("Lat=");
    Serial.print(latoutput);
    Serial.print(", Lon=");
    Serial.println(longoutput);
    send_data_to_ubidot(latoutput, ID2); //send latitude data to ubidots
    send_data_to_ubidot(longoutput, ID3);//send longitude data to ubidots
  }
  Serial.println("");
}

int sleep_flag=0;
void loop()
{
  static int LoopCount = 0;
  static int LastPrintMin = 0;
  //get user data from ubidots either hw wants to trac or not
  float flag = (int)get_data_from_ubidots(ID1); 
  //flag = 1 for tracking
  if(flag==1&&sleep_flag==0){
    SleepOut(); //wake up gps
    sleep_flag=1;
    }
  else if(flag==0&&sleep_flag==1){
    SleepIn(); //sleep gps to save power
    sleep_flag=0;
    }
  /* Check update. */
  if(sleep_flag==1){
    if (Gnss.waitUpdate(-1))
      {
      /* Get NaviData. */
      SpNavData NavData;
      Gnss.getNavData(&NavData);

      /* Print position information. */
      print_pos(&NavData);
      }
     /* Check loop count. */
  LoopCount++;
  if (LoopCount >= RESTART_CYCLE)
  {
    int error_flag = 0;

    /* Restart GNSS. */
    if (Gnss.stop() != 0)
    {
      Serial.println("Gnss stop error!!");
      error_flag = 1;
    }
    else if (Gnss.end() != 0)
    {
      Serial.println("Gnss end error!!");
      error_flag = 1;
    }
    else
    {
      Serial.println("Gnss stop OK.");
    }

    if (Gnss.begin() != 0)
    {
      Serial.println("Gnss begin error!!");
      error_flag = 1;
    }
    else if (Gnss.start(HOT_START) != 0)
    {
      Serial.println("Gnss start error!!");
      error_flag = 1;
    }
    else
    {
      Serial.println("Gnss restart OK.");
    }

    LoopCount = 0;

    /* Set error LED. */
    if (error_flag == 1)
    {
      exit(0);
    }
    }
    
 }

}
//go to sleep mode and save power
static void SleepIn(void)
{
  Gnss.stop();
  Gnss.end();
}

/**
 * @brief Go to Active mode.
 */
static void SleepOut(void)
{
  Gnss.begin();
  Gnss.start(HOT_START);
}
// reverses a string 'str' of length 'len' 
void reverse(char *str, int len) 
{ 
    int i=0, j=len-1, temp; 
    while (i<j) 
    { 
        temp = str[i]; 
        str[i] = str[j]; 
        str[j] = temp; 
        i++; j--; 
    } 
} 
  
 // Converts a given integer x to string str[].  d is the number 
 // of digits required in output. If d is more than the number 
 // of digits in x, then 0s are added at the beginning. 
int intToStr(int x, char str[], int d) 
{ 
    int i = 0; 
    while (x) 
    { 
        str[i++] = (x%10) + '0'; 
        x = x/10; 
    } 
  
    // If number of digits required is more, then 
    // add 0s at the beginning 
    while (i < d) 
        str[i++] = '0'; 
  
    reverse(str, i); 
    str[i] = '\0'; 
    return i; 
} 
  
// Converts a floating point number to string. 
void ftoa(float n, char *res, int afterpoint) 
{ 
    // Extract integer part 
    int ipart = (int)n; 
  
    // Extract floating part 
    float fpart = n - (float)ipart; 
  
    // convert integer part to string 
    int i = intToStr(ipart, res, 0); 
  
    // check for display option after point 
    if (afterpoint != 0) 
    { 
        res[i] = '.';  // add dot 
  
        // Get the value of fraction part upto given no. 
        // of points after dot. The third parameter is needed 
        // to handle cases like 233.007 
        fpart = fpart * pow(10, afterpoint); 
  
        intToStr((int)fpart, res + i + 1, afterpoint); 
    } 
} 

void httpInit(){
  GPRS.println("AT"); /* Check Communication */
  delay(200);
  /* Configure bearer profile 1 */
  GPRS.println("AT+SAPBR=3,1,\"CONTYPE\",\"Serial\"");  /* Connection type GPRS */
  delay(2000);
  GPRS.println("AT+SAPBR=3,1,\"APN\",\"gpinternet\"");  /* APN of the provider */
  delay(3000);
  GPRS.println("AT+SAPBR=1,1"); /* Open GPRS context */
  delay(3000);
  GPRS.println("AT+SAPBR=2,1"); /* Query the GPRS context */
  delay(3000);
  Serial.println("AT+HTTPINIT");  /* Initialize HTTP service */
  delay(2000); 
}

void send_data_to_ubidot(char* data, char* id){
  httpInit();
  GPRS.print(F("AT+HTTPPARA=\"URL\",\"things.ubidots.com/api/v1.6/variables/"));
  GPRS.print(id);
  GPRS.print(F("/values?token="));
  GPRS.print(TOKEN);
  GPRS.println("\"");
  delay(4000);
  GPRS.println(F("AT+HTTPPARA=\"CONTENT\",\"application/json\""));
  delay(4000);
  GPRS.print(F("AT+HTTPDATA="));
  GPRS.print(strlen(data));
  GPRS.print(F(","));
  GPRS.println(120000);
  delay(2000);
  GPRS.write(data, strlen(data));
  GPRS.println(F("AT+HTTPACTION=1"));  // HTTPACTION=1 is a POST method
  delay(6000);
  GPRS.println(F("AT+HTTPREAD"));
  Serial.println("AT+HTTPTERM");  /* Terminate HTTP service */
  delay(3000);
  Serial.println("AT+SAPBR=0,1"); /* Close Serial context */
  delay(3000);
}

float get_data_from_ubidots(char* id){
    float num;
    String raw;
    flushInput();
    httpTerm();
    httpInit();
    GPRS.print(F("AT+HTTPPARA=\"URL\",\"things.ubidots.com/api/v1.6/variables/"));
    GPRS.print(id);
    GPRS.print(F("/values?token="));
    GPRS.print(TOKEN); //&page_size=1
    GPRS.println(F("&page_size=1\""));
    delay(1000);
    GPRS.println(F("AT+HTTPACTION=0"));  //HTTPACTION=0 is GET method
    delay(4000);
    GPRS.println(F("AT+HTTPREAD"));
    char* reply = readData(3000);
    char* pch = strstr(reply,"\"value\":");
    int bodyPosinit =9+ raw.indexOf("\"value\":");
    int bodyPosend = raw.indexOf(", \"timestamp\"");
    raw.substring(bodyPosinit,bodyPosend).toCharArray(reply, 10);
    num = atof(reply); 
    GPRS.println(F("AT+HTTPTERM"));
    delay(1000);
    return num;
}

char* readData(uint16_t timeout){
  uint16_t replyidx = 0;
  char replybuffer[500];
  while (timeout--) {
    if (replyidx >= 500) {
      break;
    }
    while(GPRS.available()) {
      char c =  GPRS.read();
      if (c == '\r') continue;
      if (c == 0xA) {
        if (replyidx == 0)   // the first 0x0A is ignored
          continue;
      }
      replybuffer[replyidx] = c;
      replyidx++;
    }

    if (timeout == 0) {
      break;
    }
    delay(1);
  }
  replybuffer[replyidx] = '\0';  // null term

  while(GPRS.available()){
    GPRS.read();
  }
  return replybuffer;
}

void flushInput() {
    // Read all available serial input to flush pending data.
    uint16_t timeoutloop = 0;
    while (timeoutloop++ < 40) {
        while(Serial.available()) {
            Serial.read();
            timeoutloop = 0;  // If char was received reset the timer
        }
        delay(1);
    }
}

bool httpTerm(){
    GPRS.println(F("AT+HTTPTERM"));
    if(strstr(readData(1000),"OK")==NULL){
        return false;
    }
    return true;
}