Hello,
I am trying to seperate the GPS data & view it in another uno board. the wireless medium is 433MHZ RF modulles. I am using 2 separate uno boards one for GPS+TX & the other with RX module. Tried afew example codes in RF 433MHz & they are successful but I am having issues with the gps data.
The algo I am following is...
separate the lat, lon & date_time value
print it on serial monitor to see if its working
wrap it to a String
send it via RF module
I am using the tinyGPS library & test_with_GPS_device example
I tried to modify the sketch a bit. In a GPS logger example the lat,long&date_time is added to a string
String RF_date_time = "invalid";
String RF_lat = "invalid";
String RF_lon = "invalid";
String dataString ="";
.....
..........
dataString = RF_date_time + "," + RF_lat + "," + RF_lon;
I tried to put the data in an array to send it via RF433 module
char Sensor1CharMsg[50];// The string that we are going to send trought RF
...............
......................
sprintf(Sensor1CharMsg, "%02d/%02d/%02d %02d:%02d:%02d, %f, %f", RF_date_time, RF_lat, RF_lon);
Date, time, Lat, Lon they are decimal & float values but they are indeed strings. what to do for printing these integer contained strings? Should I use %s instead of %d & %f ?
then tried to see the output via
Serial.println(Sensor1CharMsg);
There is no output in serial monitor. then I tried using the string lenght
Serial.println(Sensor1CharMsg, Sizeof(Sensor1CharMsg));
It couldn't be be compiled. RED screen with error.
Then I tried to print the values separately
Serial.println(RF_date_time);
Serial.println(RF_lat);
Serial.println(RF_lon);
Still no output.
In the code they are defined as string. How to serial Print a string?
Cant differentiate between a string & an array or a "string" & "char". Any analogy?
The messed up code is here... The issue is in the void loop() section. lat, laon & date_time is already seperated in the gpsdump () & print float () section. All i need is to first view the "datastring" in the serial monitor & then send it to via 433MHz module. Any help shall be highly appraised.
#include <SoftwareSerial.h>
#include <TinyGPS.h>
#include <stdlib.h>
#include <VirtualWire.h>
/* This sample code demonstrates the normal use of a TinyGPS object.
It requires the use of SoftwareSerial, and assumes that you have a
4800-baud serial GPS device hooked up on pins 3(rx) and 4(tx).
*/
TinyGPS gps;
SoftwareSerial nss(3, 4);
static char dtostrfbuffer[20];
char Sensor1CharMsg[50];// The string that we are going to send trought rf
//Define String
String RF_date_time = "invalid";
String RF_lat = "invalid";
String RF_lon = "invalid";
String dataString ="";
static void gpsdump(TinyGPS &gps);
static bool feedgps();
static void print_float(float val, float invalid, int len, int prec, int RF_val);
static void print_int(unsigned long val, unsigned long invalid, int len);
static void print_date(TinyGPS &gps);
static void print_str(const char *str, int len);
void setup()
{
//Serial interfaces
Serial.begin(115200);
nss.begin(9600);
vw_setup(4000); // Bits per sec
vw_set_tx_pin(12);// Set the Tx pin. Default is 12
}
void loop()
{
bool newdata = false;
unsigned long start = millis();
// Every second we print an update
while (millis() - start < 1000)
{
if (feedgps())
newdata = true;
}
gpsdump(gps);
dataString = RF_date_time + "," + RF_lat + "," + RF_lon;
sprintf(Sensor1CharMsg, "%02d/%02d/%02d %02d:%02d:%02d, %f, %f", RF_date_time, RF_lat, RF_lon);
// Serial.println(Sensor1CharMsg);
Serial.println(RF_date_time);
Serial.println(RF_lat);
Serial.println(RF_lon);
}
static void gpsdump(TinyGPS &gps)
{
float flat, flon;
unsigned long age, date, time, chars = 0;
unsigned short sentences = 0, failed = 0;
static const float LONDON_LAT = 51.508131, LONDON_LON = -0.128002;
print_int(gps.satellites(), TinyGPS::GPS_INVALID_SATELLITES, 5);
print_int(gps.hdop(), TinyGPS::GPS_INVALID_HDOP, 5);
gps.f_get_position(&flat, &flon, &age);
print_float(flat, TinyGPS::GPS_INVALID_F_ANGLE, 9, 5, 1); //LATITUDE
print_float(flon, TinyGPS::GPS_INVALID_F_ANGLE, 10, 5, 2); //LONGITUDE
print_int(age, TinyGPS::GPS_INVALID_AGE, 5);
print_date(gps); //DATE AND TIME
print_float(gps.f_altitude(), TinyGPS::GPS_INVALID_F_ALTITUDE, 8, 2, 0);
print_float(gps.f_course(), TinyGPS::GPS_INVALID_F_ANGLE, 7, 2, 0);
print_float(gps.f_speed_kmph(), TinyGPS::GPS_INVALID_F_SPEED, 6, 2, 0);
print_str(gps.f_course() == TinyGPS::GPS_INVALID_F_ANGLE ? "*** " : TinyGPS::cardinal(gps.f_course()), 6);
print_int(flat == TinyGPS::GPS_INVALID_F_ANGLE ? 0UL : (unsigned long)TinyGPS::distance_between(flat, flon, LONDON_LAT, LONDON_LON) / 1000, 0xFFFFFFFF, 9);
print_float(flat == TinyGPS::GPS_INVALID_F_ANGLE ? 0.0 : TinyGPS::course_to(flat, flon, 51.508131, -0.128002), TinyGPS::GPS_INVALID_F_ANGLE, 7, 2, 0);
print_str(flat == TinyGPS::GPS_INVALID_F_ANGLE ? "*** " : TinyGPS::cardinal(TinyGPS::course_to(flat, flon, LONDON_LAT, LONDON_LON)), 6);
gps.stats(&chars, &sentences, &failed);
print_int(chars, 0xFFFFFFFF, 6);
print_int(sentences, 0xFFFFFFFF, 10);
print_int(failed, 0xFFFFFFFF, 9);
Serial.println();
}
static void print_int(unsigned long val, unsigned long invalid, int len)
{
char sz[32];
if (val == invalid)
strcpy(sz, "*******");
else
sprintf(sz, "%ld", val);
sz[len] = 0;
for (int i=strlen(sz); i<len; ++i)
sz[i] = ' ';
if (len > 0)
sz[len-1] = ' ';
Serial.print(sz);
feedgps();
}
static void print_float(float val, float invalid, int len, int prec, int RF_val)
{
char sz[32];
if (val == invalid)
{
strcpy(sz, "*******");
sz[len] = 0;
if (len > 0)
sz[len-1] = ' ';
for (int i=7; i<len; ++i)
sz[i] = ' ';
Serial.print(sz);
if(RF_val == 1) RF_lat = sz;
else if(RF_val == 2) RF_lon = sz;
}
else
{
Serial.print(val, prec);
if (RF_val == 1) RF_lat = dtostrf(val,10,5,dtostrfbuffer);
else if (RF_val == 2) RF_lon = dtostrf(val,10,5,dtostrfbuffer);
int vi = abs((int)val);
int flen = prec + (val < 0.0 ? 2 : 1);
flen += vi >= 1000 ? 4 : vi >= 100 ? 3 : vi >= 10 ? 2 : 1;
for (int i=flen; i<len; ++i)
Serial.print(" ");
}
feedgps();
}
static void print_date(TinyGPS &gps)
{
int year;
byte month, day, hour, minute, second, hundredths;
unsigned long age;
gps.crack_datetime(&year, &month, &day, &hour, &minute, &second, &hundredths, &age);
if (age == TinyGPS::GPS_INVALID_AGE)
{
Serial.print("******* ******* ");
RF_date_time = "invalid";
}
else
{
char sz[32];
sprintf(sz, "%02d/%02d/%02d %02d:%02d:%02d ",
month, day, year, hour, minute, second);
Serial.print(sz);
RF_date_time = sz;
}
print_int(age, TinyGPS::GPS_INVALID_AGE, 5);
feedgps();
}
static void print_str(const char *str, int len)
{
int slen = strlen(str);
for (int i=0; i<len; ++i)
Serial.print(i<slen ? str[i] : ' ');
feedgps();
}
static bool feedgps()
{
while (nss.available())
{
if (gps.encode(nss.read()))
return true;
}
return false;
}
