Issues on Setting Parameter

[PTsen]

Hi, I have tons of question about the command $PSTMSETPAR and some related command:

First of all, I would like to change the NMEA Baudrate to 38400, as the software manual said, I should transfer

"$PSTMSETPAR,1102,0x8"

"$PSTMSAVEPAR"

and NMEA gives me the result (no comma due to the way I'm processing the string):

$PSTMSETPAROK 1102*31

$PSTMSETPAR 1102 8

as the manual says, I should reset the system, so I've enter the command "$PSTMRR", and it returns "$GPTXT DEFAULT LIV CONFIGURATION*2B". But when I change my Baudrate from 9600 to 38400, I got scribbled message, only when I change back to 9600 will the message be shown properly. However, after I unpowered my stm32 and power it again, I ""sometime"" find it changes its Baudrate to 38400, vice versa. So here are my questions:

1. How to reset X-NULCEO-GNSS1A1: As I dig into the example code from cubeMS, I found that reset is done by setting low on the reset pin, wait for a while, then setting it to high, then wait for a while, but doing so doesn't make any change to the setting. So I'm not sure how the resetting is done.
2. Should I send the second command after the previous command got the return message? E.g. I should wait "$PSTMSETPAROK 1102*3" after sending the command "$PSTMSETPAR,1102,0x8" , then send the new command, or I can send "$PSTMSETPAR,1102,0x8" followed by "$PSTMSAVEPAR" immediately?

Next, I would like TESEO LIV3F to send to me only some certain message, say, $GPGGA, to do so, I need to use the command $PSTMCFGMSGL, and here is my next group of questions:

1. From "Application note - AN5203 - Teseo-LIV3F - I2C Positioning Sensor", I found an example of setting the config is done as follow:

$PSTMCFGMSGL,3,1,0,0
$PSTMSETPAR,1227,1,2 
$PSTMSAVEPAR

I can't understand, from the software manual of Teseo-LIV3F, the syntax of $PSTMCFGMSGL is <listid>,<rate>,

<list_l>,<list_h>*<checksum><cr><lf>, where listid can only be 0 or 1, I don't even know what listid 1 is since I can't

find the CBD_ID 210 and 229 relevant to msg list in the user manual, not to mention the value 3 in the example

above, also, I don't know what does "rate" here mean.

​ 2. After reconfigure the message list by the command "$PSTMCFGMSGL,0,1,0,0" and "$PSTMSAVEPAR", nothing

changed, I'm expecting this since the Baudrate doesn't change immediately, as well. When I request the

message via command $PSTMNMEAREQUEST,100000,0 (GPGLL), I didn't get what I expected, instead, I get this

​Which is totally different from the application note, and I don't know what to do, the manual is rather confusing to me.

Any advice would be great, since I'm literally having hard time getting this module to work. Thank you.

[Francesco Virlinzi]

Hi

To change NMEA baudrate you can use the following script:

====

$PSTMCFGPORT,0,0,2,new_baud_value

$PSTMSAVEPAR

$PSTMSRR

====

1. How to reset X-NULCEO-GNSS1A1

You can perform a software reset using the commands "$PSTMSRR" or an hardware reset toggling the pins Teseo-LIV3F.nReset (pins Connector-9_pin-8 on the X-Nucleo-GNSS1A1)

> I would like TESEO LIV3F to send to me only some certain message

I2C anc UART ports have separated message-list.

To change the UART-message-list you can use the following scripts:

==================

$PSTMCFGMSGL,0,1,<list_low>,<list_high>

$PSTMSAVEPAR

$PSTMSRR

==================

Let me know if this helps.

Regards

Francesco

[PTsen]

Hi, thanks for your response

First of all

===

$PSTMCFGPORT,0,0,2,0x5

$PSTMSAVEPAR

$PSTMSRR

===

What I expected: As soon as I do the software reset, the baudrate of NMEA should be the new one.

What turns out to be: The baudrate of NMEA doesn't change since changing the USART baudrate to the new one result in scribbled message, but is normal when change to original baudrate

Additional question: what does '2' mean here? According to the manual, I see the first param is portnumb (UART GPIO ID), what ID?

Next,

==================

$PSTMCFGMSGL,0,1,0,0

$PSTMSAVEPAR

$PSTMSRR

==================

What I expected: As soon as the software reset, I should receive nothing

What turns out to be: The message keeps printing as if nothing happened.

[Francesco Virlinzi]

Hi

> $PSTMCFGPORT,0,0,2,0x5

It should be:

$PSTMCFGPORT,0,0,2,115200

or

$PSTMCFGPORT,0,0,2,9600

to restore the default setting

>  what does '2' mean here?

Teseo-III has several UART port (The UART-2 is the one available on the module).

> What I expected: As soon as the software reset, I should receive nothing

Just tested and working on my side.

The periodic messages are no more sent from the module.

Could you check?

Thanks

Regards

Francesco

[PTsen]

Hi, thanks for your immediate response

First:

====

$PSTMCFGPORT,0,0,2,38400

$PSTMSAVEPAR

$PSTMSRR

====

What I expected: The baudrate should be changed after software reset

What turns out to be: The baudrate doesn't change

Second:

==================

$PSTMCFGMSGL,0,1,0,0

$PSTMSAVEPAR

$PSTMSRR

==================

It turns out that the command works. It seems like the reason is that I send "$PSTMSRR" instead of "$PSTMSRR\r\n", and I'm not sure if this is the cause, but once I take way the cr and lf, the setup doesn't change, and it works if the line contains cr and lf.

[Francesco Virlinzi]

Ciao

=====

$PSTMCFGPORT,0,0,2,38400

$PSTMSAVEPAR

$PSTMSRR

===

the scripts is correct. (just tested on my side)

Do you receive the 'OK' respond messages (i.e: $PSTMCFGPORTOK*45 and $PSTMSAVEPAROK*5C)

Moreover take into account they are NMEA message this means the correct syntax is:

$COMMAND, PARAMS,...*<checksum><cr><lf>

Therefore the scripts has to be:

$PSTMCFGPORT,0,0,2,38400*<checksum><cr><lf>

$PSTMSAVEPAR*<checksum><cr><lf>

$PSTMSRR*<checksum><cr><lf>

Teseo-Suite (if you are using it) internally appends "*<checksum><cr><lf>" on each commands

Let me know if this helps.

Regards

Francesco

[PTsen]

Hi, the problem still persists

There are few questions I want to ask:

1. All of the example in software manual is assuming the user is using Teseo-Suite, if not, we should append checksum and cr, lf at the end of the string
2. Passing the command "$PSTMCFGPORT,0,0,2,38400*4c\r\n" gives me neither "$PSTMCFGPORTOK*45" nor "$PSTMCFGPORTERROR*19", instead, I receive "$PSTMCFGPORT,0,0,2,38400*6c", which has the wrong checksum, what is happening?

Thankyou

[Francesco Virlinzi · Accepted solution]

> we should append checksum and cr, lf at the end of the string

Yes. correct.

> which has the wrong checksum, what is happening?

Really strange. I tryed all the commads and they work on my side.

Could you check your code?

Do you want share?

Just a note (sorry I forgot to say) but the whole C-Driver for Teseo-LIV3F is already online @

https://www.st.com/content/st_com/en/products/embedded-software/mcus-embedded-software/stm32-embedded-software/stm32cube-expansion-packages/x-cube-gnss1.html

in the package you will find binary for STM32 and all the C-Code. May be it could help your development.

Regards

Franceco

[PTsen]

Hi, I've checked my code, and there is some subtle mistake, resulting in the wrong checksum. Even though it works fine in online compiler.

Thank you really much, really appreciate it.