Store long data into float data

Projects Programming
1

i want to save long data into float data but the result always zero

struct NAV_PVT {
  unsigned char cls;
  unsigned char id;
  unsigned short len;
  unsigned long iTOW;          // GPS time of week of the navigation epoch (ms)

  unsigned short year;         // Year (UTC)
  unsigned char month;         // Month, range 1..12 (UTC)
  unsigned char day;           // Day of month, range 1..31 (UTC)
  unsigned char hour;          // Hour of day, range 0..23 (UTC)
  unsigned char minute;        // Minute of hour, range 0..59 (UTC)
  unsigned char second;        // Seconds of minute, range 0..60 (UTC)
  char valid;                  // Validity Flags (see graphic below)
  unsigned long tAcc;          // Time accuracy estimate (UTC) (ns)
  long nano;                   // Fraction of second, range -1e9 .. 1e9 (UTC) (ns)
  unsigned char fixType;       // GNSSfix Type, range 0..5
  char flags;                  // Fix Status Flags
  unsigned char reserved1;     // reserved
  unsigned char numSV;         // Number of satellites used in Nav Solution

  long lon;                    // Longitude (deg)
  long lat;                    // Latitude (deg)
  long height;                 // Height above Ellipsoid (mm)
  long hMSL;                   // Height above mean sea level (mm)
  unsigned long hAcc;          // Horizontal Accuracy Estimate (mm)
  unsigned long vAcc;          // Vertical Accuracy Estimate (mm)

  long velN;                   // NED north velocity (mm/s)
  long velE;                   // NED east velocity (mm/s)
  long velD;                   // NED down velocity (mm/s)
  long gSpeed;                 // Ground Speed (2-D) (mm/s)
  long heading;                // Heading of motion 2-D (deg)
  unsigned long sAcc;          // Speed Accuracy Estimate
  unsigned long headingAcc;    // Heading Accuracy Estimate
  unsigned short pDOP;         // Position dilution of precision
  short reserved2;             // Reserved
  unsigned long reserved3;     // Reserved
  unsigned char dummy[8];
};

NAV_PVT pvt;

float latitude = (float)(pvt.lat/10000000.0);
float longitude = (float)(pvt.lon/10000000.0);

if i print the latitude it will result 0.0000000

2

I'd try
float latitude = float(pvt.lat)/10000000.0;

2 Likes
3

If it is in the declaration area they will always give 0 because PVT does not have data loaded yet.

Outside of that detail, the conversion is correct.
Try this

struct NAV_PVT {
  unsigned char cls;
  unsigned char id;
  unsigned short len;
  unsigned long iTOW;          // GPS time of week of the navigation epoch (ms)

  unsigned short year;         // Year (UTC)
  unsigned char month;         // Month, range 1..12 (UTC)
  unsigned char day;           // Day of month, range 1..31 (UTC)
  unsigned char hour;          // Hour of day, range 0..23 (UTC)
  unsigned char minute;        // Minute of hour, range 0..59 (UTC)
  unsigned char second;        // Seconds of minute, range 0..60 (UTC)
  char valid;                  // Validity Flags (see graphic below)
  unsigned long tAcc;          // Time accuracy estimate (UTC) (ns)
  long nano;                   // Fraction of second, range -1e9 .. 1e9 (UTC) (ns)
  unsigned char fixType;       // GNSSfix Type, range 0..5
  char flags;                  // Fix Status Flags
  unsigned char reserved1;     // reserved
  unsigned char numSV;         // Number of satellites used in Nav Solution

  long lon;                    // Longitude (deg)
  long lat;                    // Latitude (deg)
  long height;                 // Height above Ellipsoid (mm)
  long hMSL;                   // Height above mean sea level (mm)
  unsigned long hAcc;          // Horizontal Accuracy Estimate (mm)
  unsigned long vAcc;          // Vertical Accuracy Estimate (mm)

  long velN;                   // NED north velocity (mm/s)
  long velE;                   // NED east velocity (mm/s)
  long velD;                   // NED down velocity (mm/s)
  long gSpeed;                 // Ground Speed (2-D) (mm/s)
  long heading;                // Heading of motion 2-D (deg)
  unsigned long sAcc;          // Speed Accuracy Estimate
  unsigned long headingAcc;    // Heading Accuracy Estimate
  unsigned short pDOP;         // Position dilution of precision
  short reserved2;             // Reserved
  unsigned long reserved3;     // Reserved
  unsigned char dummy[8];
};

NAV_PVT pvt;

void setup() {
  // put your setup code here, to run once:
  Serial.begin(115200);
  pvt.lat = 12345678;
  pvt.lon = 34567890;
  float latitude = (float)(pvt.lat/10000000.0);
  float longitude = (float)(pvt.lon/10000000.0);
  Serial.print("Lat: "); Serial.println(latitude,6);
  Serial.print("Lon: "); Serial.println(longitude,6);
}

void loop() {
  // put your main code here, to run repeatedly:
}

And the console shows

Lat: 1.234568
Lon: 3.456789
1 Like
4

Why ?
Long and float has the same data length, but the long is more accurate. It would be better to transform and operate with data as long type.

5

this is the full code

void direction_read() {
  if (processGPS()) {
    compass.read();
    heading = compass.getAzimuth();
  
    radlat_UGV = latitude_UGV*toRad;
    radlon_UGV = longitude_UGV*toRad;
    radlat_wp = lat_wp[wp]*toRad;
    radlon_wp = lon_wp[wp]*toRad;
    o = sin(radlon_wp - radlon_UGV)*cos(radlon_wp);
    t = (cos(radlat_UGV)*sin(radlat_wp))-(sin(radlat_UGV)*cos(radlat_wp)*cos(radlon_wp - radlon_UGV));              
    theta = atan2(o,t);
    //ubah ke derajat dari radian
    bearing = theta*toDeg;
    
    //kalo nilai derajat minus, ditambah 360 supaya bisa jadi positif
    if (bearing < 0){
      bearing = bearing + 360;
    }

    direction = heading - bearing;

    // DEBUG:
    Serial.print("HEAD: ");
    Serial.print(heading);
    Serial.print(" | ");
    Serial.print("BEAR: ");
    Serial.print(bearing);
    Serial.print(" | ");
    Serial.print("DIR: ");
    Serial.print(direction);
    Serial.print(" | ");
  } else {
    Serial.print(F("INVALID DIR"));
    Serial.print(" | ");
  }
}

void distance_read() {
  if (processGPS()) {
    latitude_UGV = float(pvt.lat)/10000000.0;
    longitude_UGV = float(pvt.lon)/10000000.0;
    acc = float(pvt.vAcc);
    radlat_UGV = latitude_UGV*toRad;
    radlon_UGV = longitude_UGV*toRad;
    radlat_wp = lat_wp[wp]*toRad;
    radlon_wp = lon_wp[wp]*toRad;
    // haversine
    a = (sq(sin(radlat_wp - radlat_UGV)/2)+cos(radlat_UGV)*cos(radlat_wp)*(sq(sin(radlon_wp-radlon_UGV)/2))); 
    c = 2*atan2(sqrt(a), sqrt(1-a));
    // kali ke radius bumi dalam meter
    distance = c*6371000;

    // DEBUG:
    Serial.print("LAT: ");
    Serial.print(latitude_UGV);
    Serial.print(" | ");
    Serial.print("LON: ");
    Serial.print(longitude_UGV);
    Serial.print(" | ");
    Serial.print("DIST: ");
    Serial.print(distance);
    Serial.print(" | ");
  } else {
    Serial.print(acc);
    Serial.print(" | ");
  }
}

void otomasi() {
  /* Autonomous Switching */
  while (Serial3.available() > 0) {
    if (processGPS()) {
      direction_read();
      distance_read();

      if (latitude_UGV != 0 && longitude_UGV != 0) {
        // Read Input: Jarak
        g_fisInput[0] = distance;
        // Read Input: Sudut
        g_fisInput[1] = direction;

        g_fisOutput[0] = 0;
        g_fisOutput[1] = 0;

        if (distance < 2) {
          UGVControl(0, 165);
          delay(500);
          UGVControl(0, 35);
        } else {
          fis_evaluate();

          UGVSpeed = g_fisOutput[0];
          UGVDirection = g_fisOutput[1];
          int ReverseDirection = map(UGVDirection, 0, 180, 180, 0);

          UGVControl(UGVSpeed, ReverseDirection);

          // DEBUG:
          Serial.print("Speed: ");   
          Serial.print(UGVSpeed);   
          Serial.print(" | "); 
          Serial.print("Direction: ");   
          Serial.println(UGVDirection);
        }

        // DEBUG:
        Serial.print("Speed: ");   
        Serial.print(UGVSpeed);   
        Serial.print(" | "); 
        Serial.print("Direction: ");   
        Serial.println(UGVDirection);
      } else {
        UGVSpeed = 0;
        UGVDirection = 90;

        UGVControl(UGVSpeed, UGVDirection);

        // DEBUG:
        Serial.print("Speed: ");   
        Serial.print(UGVSpeed);   
        Serial.print(" | "); 
        Serial.print("Direction: ");   
        Serial.println(UGVDirection);
      }
    }
  }
}

void setup()
{
  Serial.begin(9600);
  GPS10();
  // Setup Compass
  compass.init();
  compass.setCalibration(-1345, 1112, -1855, 691, -62, 353);
  compass.setSmoothing(10,true);  

  // Setup GPS
  Serial3.begin(115200);

  //Setup Motor DC
  pinMode(motor1EN, OUTPUT);
  pinMode(motor1PWM1, OUTPUT);
  pinMode(motor1PWM2, OUTPUT);

  // Setup Motor Servo
  servo.attach(3);
 
  radio.begin();                    //it activates the modem
  radio.openReadingPipe(1, pipe);   //determines the address of our modem which receive data
  radio.setPALevel(RF24_PA_MAX);
  radio.startListening();   
}

void loop() {
  unsigned long msLastRX;

  if (radio.available() > 0) {
    msLastRX = millis();
    radio.read(data, sizeof(data));
  
    //data X
    datag = map(data[0], 503, 1023, 0, 255);
    if(datag < 0)
    {
      digitalWrite(motor1PWM1, LOW);
      digitalWrite(motor1PWM2, LOW);
      analogWrite(motor1EN, 0);
    } 
    else
    {  
      digitalWrite(motor1PWM1, HIGH);
      digitalWrite(motor1PWM2, LOW);
      analogWrite(motor1EN, datag);
    }

    datar = map(data[1], 0, 1023, 180, 0);
    Serial.println(datar);
    Serial.print(" , ");
    Serial.println(datag);
    servo.write(datar);
  }

  if (millis() - msLastRX >= 2000) {
    otomasi();
    
  }
}

im trying to store data to float latitude_UGV with pvt.lat/10000000.0, so the formulas can use it

6

the pvt.lat get data from gps, im parsing without using library

7

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