Serial and I2C comms examples for Airbot UBlox GPS and compass part

ublox-i2c.c

#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>

#include <stdio.h>
#include <string.h>
#include <errno.h>

#include <linux/i2c-dev.h>

int main() {
  int file;
  int adapter_nr = 1; // 1 for rPi rev 2, 0 for rev 1
  char filename[20];

  snprintf(filename, 19, "/dev/i2c-%d", adapter_nr);
  file = open(filename, O_RDWR);
  if (file < 0) {
    /* ERROR HANDLING; you can check errno to see what went wrong */
    exit(1);
  }

  int addr = 0x1e;
  if (ioctl(file, I2C_SLAVE, addr) < 0) {
    /* ERROR HANDLING; you can check errno to see what went wrong */
    exit(1);
  }
  i2c_smbus_write_word_data(file, 0x02, 0x00);

  unsigned char values[6];
  values[0] = i2c_smbus_read_word_data(file, 0x03);
  values[1] = i2c_smbus_read_word_data(file, 0x04);
  values[2] = i2c_smbus_read_word_data(file, 0x05);
  values[3] = i2c_smbus_read_word_data(file, 0x06);
  values[4] = i2c_smbus_read_word_data(file, 0x07);
  values[5] = i2c_smbus_read_word_data(file, 0x08);

  // print out result
  printf("Values: X MSB: %d, X LSB: %d, Y MSB: %d, Y LSB: %d, Z MSB: %d, Z LSB: %d\n",
    values[0],values[1],values[2],values[3],values[4],values[5]);
  unsigned char status;
  status = i2c_smbus_read_word_data(file, 0x09);
  printf("Status: %d",status);

  return 0;
}

ublox.c

#include <stdio.h>
#include <string.h>
#include <errno.h>

#include <wiringSerial.h>

#include <nmea/nmea.h>

int main() {
  int fd;
  if ((fd = serialOpen("/dev/ttyAMA0",9600))<0) {
    fprintf(stderr,"FAIL");
    return 1;
  }
  char buff[2048];
  int size, it = 0;
  FILE *file;
  nmeaPOS dpos;
  nmeaINFO info;
  nmeaPARSER parser;
  nmea_zero_INFO(&info);
  nmea_parser_init(&parser);

  file = fdopen(fd,"r");

  for (;;) {
    putchar(serialGetchar(fd));
    while(!feof(file)) {
      size = (int)fread(&buff[0],1,100,file);
      nmea_parse(&parser,&buff[0],size,&info);
      nmea_info2pos(&info,&dpos);
      printf("%03d, Lat: %f, Lon: %f, Sig: %d, Fix: %d\n",
            it++, dpos.lat, dpos.lon, info.sig, info.fix
            );
    }

    fseek(file, 0, SEEK_SET);
  }
  nmea_parser_destroy(&parser);
  fclose(file);
}

ubloxp.c

#include <stdio.h>
#include <string.h>
#include <errno.h>

#include <wiringSerial.h>

int main() {
  int fd;
  if ((fd = serialOpen("/dev/ttyAMA0",9600))<0) {
    fprintf(stderr,"FAIL");
    return 1;
  }

  for (;;) {
    putchar(serialGetchar(fd));
    fflush (stdout) ;
  }
}

very good，helpful

Hi, I'm trying to use the "ublox.c" but I get no values. Could there be a problem with the way the data is gathered from the uart port?

Hi, i am trying to build the "ublox-i2c.c" code i get some error like this:
(.text+0x1ac): undefined reference to i2c_smbus_write_i2c_block_data' (.text+0x1ac): undefined reference to i2c_smbus_read_i2c_block_data'
collect2: error: ld returned 1 exit status
makefile:106: recipe for target 'all' failed
make: *** [all] Error 1
could please let me ,what are header and libraries i need to add in that file?. i am using makefile to build that file for ARMv9.