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
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
EDIT2: i have tryed both usb to the raspberry and the pc with the u center but none of this changed the rate of the gps!! edit 3: no luck i’ve tryed eaven an update of the firmware but nothing it’s like it dose not like changing configuration
Setup pipes
Firmware update tool launched
-p STDIO -b 9600:9600:9600 -F "C:\Program Files (x86)\u-blox\u-center_v20.01\flash.xml" -s 1 -t 1 -v 1 "D:\dowload\EXT_G60_LEA-6H.fd1146bafac24b1347701312d42bb698.bin"
----------CMD line arguments-----------
Image file: D:\dowload\EXT_G60_LEA-6H.fd1146bafac24b1347701312d42bb698.bin
Flash: <compiled-in>
Fis: C:\Program Files (x86)\u-blox\u-center_v20.01\flash.xml
Port: STDIO
Baudrates: 9600/9600/9600
Safeboot: 1
Reset: 1
AutoBaud: 0
Verbose: 1
Erase all: 1
Erase only: 0
Training sequence: 1
Chip erase: 0
Merging FIS: 0
Update RAM: 0
Use USB alt: 0
---------------------------------------
0.0 u-blox Firmware Update Tool version 19.03
0.0 Updating Firmware 'D:\dowload\EXT_G60_LEA-6H.fd1146bafac24b1347701312d42bb698.bin' of receiver over 'STDIO'
0.0 - Opening and buffering image file
0.0 - Verifying image
0.0 Image (file size 395996) for u-blox6 accepted
0.0 Image Ver '7.03 (45970) Mar 17 2011 16:26:24'
0.0 - CRC= 0x10F85FE1 0xF912EA5A
0.0 - Trying to open port STDIO
0.0 - Setting baudrate to 9600
0.2 - Sending training sequence
1.2 - Retry poll
2.2 - Retry poll
3.2 - Retry poll
3.2 ERROR: Version poll failed.
3.2 Firmware Update FAILED
Firmware Update Utility has unexpectedly terminated
Exit code (2)
Question
How can Rpi change Neo-6M / 8M GPS measurement/navigation update rates?
Answer
Short Answer
Contents
Part A - Using ublox u-centre
Part B - Using Rpi CuteCom
Part C - Using Thonny pytonPart A – Using u-center to do the frequency setting
u-center screen below shows if measurement frequency is set to 0.25Hz, then the test measurements repeats every 4 seconds.
Part B – Using cuteCom to send UBX message to change update rate to 4 seconds
(1) Try end measurement/navigation frequency command with the two check sum bytes. See Appendix E for an example to calculate the check sum for a update rate to 4000mS command.
(2) Try end UBX message with CR, LF. (update – CR, LF is not necessary for hex input, only necessary for text input)
Note – it is much more newbie friendly to use GUI Rpi terminal emulator cuteCom than CLI bash echo and cat.
I have compiled a command message to set the measurement rate to 4 seconds. Then I used cuteCom to input the 14 byte command string to Neo-8M serial. Neo-8M accepted the command and measurement rate became 4 seconds.
Part C – Using Rpi4B Thonny Python to set Neo-8M update rate
Now I am thinking of using thonny python 3.7.3 to set the Neo-8M measurement update rates. To make thing simple, I will only handle the RMC sentence, as shown below:
References
(1) NEO-M6 Receiver Description Including Protocol Specification – ublox
(2) NEO-M6 GPS NMEA message parsing in python (with checksum calculation) – tomazas/nmea_ublox.py 2015
(3) NEO-M6 How to update system Date & Time from GPS in python (with checksum calculation) – 2016dec15
(4) NEO-M8 Receiver description Including protocol specification R19 – 2020may14
(5) NEO-M8 concurrent GNSS modules Product sheet R07 – 2020apr30
(6) NEO-M8 GNSS modules Hardware integration manual R07 – 2020may20
(7) Fletcher’s Checksum – Wikipedia
(8) Fletcher’s Checksum – TutorialsPoint
(9) Endianness (Big and Little Endian) -Wikipedia
(11) Getting Started with U-Center for u-blox – SparkFun
(12) SparkFun GPS-RTK Board – NEO-M8P-2 – US$200
(13) GPS-RTK Hookup Guide – SparkFun
(14) What is GPS RTK? – SparkFun
(15) Enable or disable NMEA datasets in u-blox GPS module – HandHeldGroup 2018apr18
(16) Enabling/disabling NMEA sentences on u-Blox gps receiver? – Asked 4 years ago, Viewed 13k times
(17) GIS StackExchange
(19) NMEA (National Marines Electronics Association) Official Web Site
(20) NMEA 0183 V4.10 Standard – NMEA
(21) NMEA v3.01 data – gpsInfo.org
(22) Global Positioning System, Principle and Practices – Satheesh Gopi, McGraw-Hill 2005
(23) BeiDou – Wikipedia
(24) NEO-M9N module product summary – u-blox
(25) Multiple UART/serial loopback program v0.00 tlfong01 2019jun03
(27) AliExpress USB to TTL adapter USB to serial converter with real FTDI USB UART IC FT232RL – US$2.4
(29) UbloxRAW – UBX messages providing raw measurements – OpenStreetMap
(30) AllStar GNSS Receiver Protocol Specification V2.3 – AllStar, China Electronics
(31) NEO-6M GPS Module (5V Vcc, with schematic) – SunFounder
Appendices
Appendix A – Set rates
Appendix B – UBX Checksum
Appendix C – NEO-8M Set Measurement and Navigation Update Rates
Appendix D – UBX Checksum Program
Appendix E – Python program to calculate checksum
# fletcher_chksum02.py Fletcher 8-bit checksum - tlfong01 2020jun22hkt2147
# *** NEO-6M/8M IBX Message Examples ***
# --------------------------------------------------------------------------------------------------------------------
# synC1 synC2 class id length measRate navRate timeRef checkSum measurement update rate
# --------------------------------------------------------------------------------------------------------------------
# 0xb5, 0x62, 0x06, 0x08, 0x06, 0x00, 0x64, 0x00, 0x01, 0x00, 0x01, 0x00, 0x7A, 0x12 measRate 0x64 = 100ms = 0.1 sec
# 0xB5, 0x62, 0x06, 0x08, 0x06, 0x00, 0xC8, 0x00, 0x01, 0x00, 0x01, 0x00, 0xDE, 0x6A measRate 0xc8 = 212ms = 0.2 sec
# 0xB5, 0x62, 0x06, 0x08, 0x06, 0x00, 0xa0, 0x0f, 0x01, 0x00, 0x01, 0x00, 0xC5, 0xC5 measRate 0xfa0 = 4000ms = 4.0 sec
# --------------------------------------------------------------------------------------------------------------------
dataByteList01 = [0x06, 0x08, 0x06, 0x00, 0x64, 0x00, 0x01, 0x00, 0x01, 0x00]
dataByteList02 = [0x06, 0x08, 0x06, 0x00, 0xC8, 0x00, 0x01, 0x00, 0x01, 0x00]
dataByteList03 = [0x06, 0x08, 0x06, 0x00, 0xa0, 0x0f, 0x01, 0x00, 0x01, 0x00] # measRate = 0xa0 0x0f = 0xfa0 = d4000
def calcCheckSum(dataByteList):
ckA = 0
ckB = 0
for dataByte in dataByteList:
ckA = ckA + dataByte
ckB = ckB + ckA
ckA = ckA & 0xff
ckB = ckB & 0xff
print(hex(ckA), hex(ckB))
return
calcCheckSum(dataByteList01)
calcCheckSum(dataByteList02)
calcCheckSum(dataByteList03)
# *** End of program ***Appendix F – NMEA v3.01 data – gpsInfo.org
NMEA v3.01 data – gpsInfo.org
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Let me see. My CuteCom is using ttyUSB0 and you ttyAMA0. If you want to use ttyUSB0, then say so to CuteCom. But if you want to talk USB to USB (or SPI or I2C) then you might like to consider SparkFun’s USD200 recommendation (Ref 12). By the way, I tried S0, AMA0, Serial0, and USB0 and found all except AMA0 not always working. So I almost always use USB0 in my experiments. Please also see my comments to @tqhien about my bad experiences on AMA0. Another reason of using ttyUSB0 is that my plan is using ttyUSBn for more than 6 GNSSs at the same time. – tlfong01 Jun 24 at 1:15
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1eaven with usb the update rate dose not change i have bougth amazon.it/dp/B013QRUA6W i can read without a problem but the rate dose not change – awaska 2 days ago
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@awaska, your €7 USB to TTL cable seems unusual. Did you get it long long ago? I have never seen such a complicated adapter, with TxL and RxL, and “Sleep” terminal. I guess you should have capped the 5V/3V jumper to 3V. But there might be other settings that cause trouble. You might consider getting a simple, cheapy one like Refs 27, 28. – tlfong01 yesterday
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1is this good ? ebay.it/itm/113733167929 or is this better ebay.it/itm/333612681760 because i can’t wait 3 month for aliexpress or pay 60 $ – awaska yesterday
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Ah, wait a minute. To double check, I googled and found it OK to use for Rpi. I could not find any schematic but I guess TxL and RxL are just TxD and RxD related, but perhaps routed to LEDs. It is useful for those who wanted to use more UART signals, or RTS, CTS to notify Arduino and ESP8266 to reset or send a new sketch, instead of manually pushing a button. For new versions of ESP8266/32, such manual push button is replaced by software commands, so CTS and RTS are no longer needed. In short, don’t waste money getting a new one. BTW. what did you use before that, perhaps this is also good. – tlfong01 yesterday
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I now think that if either your old and new USB/TTL adapter not working for u-center/cuteCom to change update rate, then there is not likely the adapter’s fault. I now think that there is 10% chance that your neo-6m is bad, so perhaps you might consider getting another neo-7m or 8m to do swap testing. Or if you can wait a couple of days, I can search my junk box for a 6m and repeat your experiment, to hopefully find some thing important that we are missing. / to continue, … – tlfong01 yesterday
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And in case you don’t wish to waste time sit and do nothing, let me give you one assignment: (1) Read Refs 15, 16, to learn how to enable/disable a NMEA dataset, (2) Read Appendix F to understand the NMEA datasets RMC, and ZDA, then (3) Try to use u-centre to enable RMC and ZDA, and disable all others. My neo troubleshooting program will suppose your neo only updates RMC and ZDA, so you better get prepared. Ah. bed time, so see over or after the weekend. Cheers. – tlfong01 yesterday
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1i’think is the gps module because i can’t change any configuration , i follow the exact same procedure but it dose not add message and it dose not remove them .searching online i fonund thath you can send a file of configuration and when i do that “` … timeout occurred without receiving an answer. Retrying…! Sending: CFG-MSG – B5 62 06 01 08 00 F0 02 01 01 01 01 01 01 07 46 … Sending: CFG-MSG – B5 62 06 01 08 00 F0 02 01 01 01 01 01 01 07 46 … … failed due to timeout! “` so i will stuck with 1hz of update rate – awaska yesterday
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(1) Well, give me the link to the tutorial that says “you can send a file of configuration, …”. (2) You seems to say that your Neo6M is not receiving your command message, but there are many possibilities, such as (a) your Neo is deaf, (b) your RxD wire is broken. (c) Serial speed both side don’t match, but you told me that you tried the loop back OK, but perhaps your checksum is wrong, or text commend without CR/LF, … In short, there are 101 causes of trouble, … – tlfong01 yesterday
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1this is the guide is old i know but i wanted to try github.com/jlnaudin/x-drone/wiki/… , i have tryed the serial loopback and it works with the usb to serial so deaf neo 6M? – awaska 18 hours ago
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Or perhaps little Neo is starving, therefore too weak to stand up to listen outside. You might like to check out SounFounder instructions to see how much you need to feed a neo: wiki.sunfounder.cc/index.php?title=Ublox_NEO-6M_GPS_Module. Neo needs 5 big Macs a meal, but are you only giving it 3 little Macs? – tlfong01 3 hours ago
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Another thing is that Rpi (especially RpiZ/W) might only like popular UART drivers such as PL20xx, CH34x etc. Yours with the not so popular FTDI driver might not be welcome by Rpi/RpiZ/W. So you might like to try your luck other cables. Me using CH340 work happily. Reference: “Rpi3 USB serial cables discussion”? raspberrypi.stackexchange.com/questions/96697/…. Cheers. – tlfong01 3 hours ago
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So you see. USB/TTL adapters using FTDI chips are not welcome by Rpi: raspberrypi.stackexchange.com/questions/113820/…. On the other hand PL2302 and CH340 are welcome. – tlfong01 35 mins ago
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I just read that for GPS, AMA0 is only for Rpi1,2. and S0 for others. You see, it is so confusingly depressing! stackoverflow.com/questions/52248914/… – tlfong01 6 mins ago
You can send a string to your Neo with the following sentence (I didn’t check the validity of your bytes):
echo -en '\xB5\x62\x06\x08\x06\x00\xC8\x00\x01\x00\x01\x00\xDE\x6A' > /dev/ttyAMA0But you need to be under the root user for both side of the “>” character : if you do only
sudo echo [...] > /dev/ttyAMA0the echo command is executed as root, but opening device ttyAMA0 for writing is not.
So you’ll have to make a “sudo su” before all that.
As for your program, it’ll have to be executed as root to be able to open /dev/ttyAMA0 for writing.
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Many thanks for your advice and clarification. I found “/dev/ttyAMA0” and “/dev/Serial0″ problematic. And ”sudo su” seems to solve the problem. On the other hand, “/dev/ttyS0” and “/dev/ttyUSB0” seems problem free. – tlfong01 Jun 23 at 9:30
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1Raspberry Pi has 2 uart : PL011 (/dev/ttyAMA0) and miniUart (/dev/ttyS0). Then, depending of the Pi, primary and secondary order is not the same. For example, ZeroW, Pi3 and Pi4 define Primary (/dev/serial0) on the miniuart and the secondary (/dev/serial1) is used by bluetooth. On PiZero, Pi1 and Pi2, primary is on PL011 and secondary on miniuart ! issue a
ls -l /devto know what is the configuration. Note that in config.txt, device tree overlay may be used to change those settings. See link for details – tqhien 2 days ago -
1On your photos, you connected your (serial, not USB) GPS on the PL011 (ttyAMA0). You need to disable BT to get access to AMA0, with a
dtoverlay=pi3-disable-btin config.txt (boot partition) and remove any mention to ttyAMA0 in cmdline.txt (also on boot partition). – tqhien 2 days ago -
1i have already done it but still nothing eaven with direct connection between ucenter and the module! – awaska 2 days ago
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1U-Center is a Windows program. For Rpi, I do only console. Also, Neo-GPS is 9600 bauds, so you may need to add
sudo stty -F /dev/ttyAMA0 speed 9600to set that before any other thing. For example, gpsd is by default set to 4800 and without that instruction, communication can’t be established. With all that, I can set and get GPS data from my PiZero and Pi3. – tqhien 2 days ago
Categories: Uncategorized
tlfong01.blog 
echo "test" > /dev/serial0andcat -v < /dev/serial0i can see test so the serial is working, i’ve tryed trougth the u-center with network serial for controlling the gps but still the gps won’t change i’ve retryed with bash ans the hex directly given from the u-center but still the update rate won’t change, is wrong how i wrote the code in python for writing the hex? – awaska Jun 18 at 15:18/dev/ttyAMA0withechois not a byte. – Ingo Jun 18 at 17:40echo -e -n "\xB5\x62\x06\x01\x08\x00\xF0\x01\x01\x00\x00\x01\x01\x00\x03\x35" > /dev/serial0 echo -e -n "\xB5\x62" > /dev/serial0i read nothing from the serialcat -v < /dev/serial0but if i sendecho "test" > /dev/serial0strange stuff append, the word test is repited multiple time with incrising space – awaska Jun 18 at 19:48cat -v < /dev/serial0 test test test test test test test– awaska Jun 18 at 19:52