Hi i’m tryng to change the update rate of my gps tracker(neo 6m ublok) i know the byte that i need to send are 0xB5,0x62,0x06,0x08,0x06,0x00,0xC8,0x00,0x01,0x00,0x01,0x00,0xDE,0x6A

i’ve tried echo -e "\xB5\x62\x06\x08\x06\x00\xC8\x00\x01\x00\x01\x00\xDE\x6A" > /dev/ttyAMA0

and with the service stopped i also tryed with a program in c

        #include <stdio.h>
        #include <fcntl.h>   /* File Control Definitions           */
        #include <termios.h> /* POSIX Terminal Control Definitions */
        #include <unistd.h>  /* UNIX Standard Definitions          */ 
        #include <errno.h>   /* ERROR Number Definitions           */

        void main(void)
        {
                int fd;/*File Descriptor*/

                printf("\n +----------------------------------+");
                printf("\n |        Serial Port Write         |");
                printf("\n +----------------------------------+");

                /*------------------------------- Opening the Serial Port -------------------------------*/

                /* Change /dev/ttyUSB0 to the one corresponding to your system */

                fd = open("/dev/ttyAMA0",O_RDWR | O_NOCTTY | O_NDELAY); /* ttyUSB0 is the FT232 based USB2SERIAL Converter   */
                                                                        /* O_RDWR Read/Write access to serial port           */
                                                                        /* O_NOCTTY - No terminal will control the process   */
                                                                        /* O_NDELAY -Non Blocking Mode,Does not care about-  */
                                                                        /* -the status of DCD line,Open() returns immediatly */                                        

                if(fd == -1)                                            /* Error Checking */
                   printf("\n  Error! in Opening ttyUSB0  ");
                else
                   printf("\n  ttyUSB0 Opened Successfully ");


                /*---------- Setting the Attributes of the serial port using termios structure --------- */

                struct termios SerialPortSettings;      /* Create the structure                          */

                tcgetattr(fd, &SerialPortSettings);     /* Get the current attributes of the Serial port */

                cfsetispeed(&SerialPortSettings,B9600); /* Set Read  Speed as 9600                       */
                cfsetospeed(&SerialPortSettings,B9600); /* Set Write Speed as 9600                       */

                SerialPortSettings.c_cflag &= ~PARENB;   /* Disables the Parity Enable bit(PARENB),So No Parity   */
                SerialPortSettings.c_cflag &= ~CSTOPB;   /* CSTOPB = 2 Stop bits,here it is cleared so 1 Stop bit */
                SerialPortSettings.c_cflag &= ~CSIZE;    /* Clears the mask for setting the data size             */
                SerialPortSettings.c_cflag |=  CS8;      /* Set the data bits = 8                                 */

                SerialPortSettings.c_cflag &= ~CRTSCTS;       /* No Hardware flow Control                         */
                SerialPortSettings.c_cflag |= CREAD | CLOCAL; /* Enable receiver,Ignore Modem Control lines       */ 


                SerialPortSettings.c_iflag &= ~(IXON | IXOFF | IXANY);          /* Disable XON/XOFF flow control both i/p and o/p */
                SerialPortSettings.c_iflag &= ~(ICANON | ECHO | ECHOE | ISIG);  /* Non Cannonical mode                            */

                SerialPortSettings.c_oflag &= ~OPOST;/*No Output Processing*/

                if((tcsetattr(fd,TCSANOW,&SerialPortSettings)) != 0) /* Set the attributes to the termios structure*/
                    printf("\n  ERROR ! in Setting attributes");
                else
                    printf("\n  BaudRate = 9600 \n  StopBits = 1 \n  Parity   = none");

                /*------------------------------- Write data to serial port -----------------------------*/

                char write_buffer[] = "A";      /* Buffer containing characters to write into port           */
                unsigned char packet[] = { 0xB5,  0x62, 

        0x06, // 

        0x08, // 

        0x06, // length

        0x00, // 

        0x64, // measRate, hex 64 = dec 100 ms

        0x00, // 

        0x01, // navRate, always =1

        0x00, // 

        0x01, // timeRef, stick to GPS time (=1)

        0x00, // 

        0x7A, // CK_A

        0x12, // CK_B

    };
                int  bytes_written  = 0;        /* Value for storing the number of bytes written to the port */ 
                //for(int i=0;i<14;i=i+1){
                //      printf(packet[i]);
//}
                bytes_written = write(fd,packet,sizeof(packet));/* use write() to send data to port                                            */
                                                                             /* "fd"                   - file descriptor pointing to the opened serial port */
                                                                             /* "write_buffer"         - address of the buffer containing data              */
                                                                             /* "sizeof(write_buffer)" - No of bytes to write                               */
                char buf [100];
int n = read (fd, buf, sizeof buf);
                printf(buf);
                printf("\n  %s written to ttyUSB0",write_buffer);
                printf("\n  %d Bytes written to ttyUSB0", bytes_written);
                printf("\n +----------------------------------+\n\n");

                close(fd);/* Close the Serial port */

        }

and with python

import serial
#from serial import Serial

import time

import string

import pynmea2

port="/dev/ttyAMA0"
ser=serial.Serial(port, baudrate=9600 ,   parity=serial.PARITY_NONE,

  stopbits=serial.STOPBITS_ONE,

  bytesize=serial.EIGHTBITS,)

#serdata= bytearray([0xB5,0x62,0x06,0x08,0x06,0x00,0xC8,0x00,0x01,0x00,0x01,0x00,0xDE,0x6A,0xB5,0x62,0x06,0x01,0x08,0x00,0xF0,0x01,0x00,0x00,0x00,0x00,0x00,0x01,0x01,0x2B]) #0x06"0x00"0xC8"0x00"0x01"0x00"0x01"0x00"0xDE"0x6A"

#serdata= bytearray([0xB5,0x62,0x06,0x08,0x06,0x00,0xC8,0x00,0x01,0x00,0x01,0x00,0xDE,0x6A])
#print(serdata)
ser.write(b"$PUBX,40,GLL,0,0,0,0*5D\r\n")
#ser.write(bytes([181,98,6,8,6,0,100,0,1,0,1,0,122,18])) # 5hz
#ser.write(b'$PUBX,40,GLL,1,0,0,0,0,0*5D')
#ser.write(serdata)
#ser.flush()
#ser.write(bytearray([181, 98, 6, 1, 8, 0, 240, 1, 0, 0, 0, 0, 0, 1, 1, 43])) #GxGLL off
#serdatadi=bytearray([0xB5,0x62,0x06,0x01,0x08,0x00,0xF0,0x03,0x00,0x00,0x00,0x00,0x00,0x01,0x03,0x39])
#serdatadi2=bytearray([0xB5,0x62,0x06,0x01,0x08,0x00,0xF0,0x04,0x00,0x00,0x00,0x00,0x00,0x01,0x04,0x40])
#print(serdatadi2)
#ser.write(b"0xB5,0x62,0x06,0x01,0x08,0x00,0xF0,0x03,0x00,0x00,0x00,0x00,0x00,0x01,0x03,0x39")
#ser.write(serdatadi2)
#ser.write(serdatadi3)
#ser.write(b"0xB5,0x62,0x06,0x01,0x08,0x00,0xF0,0x00,0x00,0x00,0x00,0x00,0x00,0x01,0x00,0x24")
#ser.write(b'\xb5b\x06\x08\x06\x00\x1e\x00\x01\x00\x00\x003l')
while True:

        #port="/dev/ttyAMA0"

        #ser=serial.Serial(port, baudrate=9600, timeout=0.5)

        dataout = pynmea2.NMEAStreamReader()
        newdata=ser.readline()
        print(newdata)

        #print(newdata[0:6] == "$GPRMC")
        if (newdata[0:6] == b"$GPRMC"):
                print("vivo")
                newmsg=pynmea2.parse(newdata.decode("utf-8"))
                print(newmsg)
                lat=newmsg.latitude

                lng=newmsg.longitude

                gps = "Latitude=" + str(lat) + "and Longitude=" + str(lng)

                print(gps)

but nothig change the navigation update rate of the device

all of the byte code came from the manual of the device
https://www.u-blox.com/sites/default/files/products/documents/u-blox6_ReceiverDescrProtSpec_%28GPS.G6-SW-10018%29_Public.pdf

and this

https://medium.com/@cglabs/neo-6m-gps-howto-boost-data-receiving-speed-neo-6-neo-7-neo-8-487275eff1c6

and this

https://forum.arduino.cc/index.php?topic=470763.0  

EDIT: i’ve tryed both of the response but none of them worked  what i have to do if i want to connect with usb instread of uart