Teseo-LIV4F Hot Start

[KOzdi]

Hello, I am a newbie on GNSS modules, trying to understand behavior of module. I look at Software Manual and all the commands, PSTMHOT, PSTMWARM, PSTMCOLD command get my attention. When we use these set of commands ?

For example I have teseo module with back up battery on, after cold start, module starts to work for some time and I turn the power off. Maybe after 1 hour maybe after 1 month I will turn the power on, not obvious...Modul sometimes should hot start sometimes warm sometimes cold. Module should decide itself by checking itself right ? There is no point in writing these commands. The question,in which scenario should we use these commands ? and also I have been looking for code example that can guide me when understanding how to configure from scratch.

And also I upgrade the firmware to 4.6.6.5.6, when I configure with PSTMSETPAR command, it works with problem, fox example I want to open some kind of messages but command open other message types. It seems command list in software document doesn't match for newer firmware. I need full CDB block to be able to configure appropriately. Where can i find that ? or guide me please I get stuck because of lack of proper documentation

Thanks in advance.

[GalaxyQuest]

Majority of the use cases you are right, there is no need to send these commands when the module wakes up. It will acquire and track satellites on its own.

However if you want to configure a module and not want to use old ephemeris data (maybe because your sky view is different being in different continent or large geographical distance where skyview is very different), then you can send a PSTMCOLD command, so the GNSS module starts fresh acquisition and tracking.

You can upgrade software using TeseoSuite and also use TeseoSuite to send commands to configure the unit. (Some common commands sent are setting constellations, fix rate and baud rate). If you are using 10Hz fix rate, then be mindful to change baud-rate as well. Default 115200 should be ok but depending on messages you output you can increase it.

I am attaching a file showing how to upgrade firmware. In Teseo Suite go to Help > User Manual to understand more about capabilities about Teseo Suite.

We also have X-CUBE-GNSS1 library as part of STM32 Cube Expansion package. Please refer to this. For LIV4F, please do NOT use Firmware Updater example as this is only tested with LIV3x.

[KOzdi]

Thanks for the answer I understand, I upgrade firmware and try get accurate position and made some test in teseo suite program. I have this antenna on this link:

https://www.mouser.com.tr/ProductDetail/Taoglas/AGVLB.25B.07.0060A?qs=ST9lo4GX8V1MB5x5VzOAfw%3D%3D&srsltid=AfmBOorE_rsO4_VlBNajcm7y0OyFteNTKoCJAuI5TzDMrF8gxcbGdTZJ 

I activated GPS,GLONASS,GALILEO and QZSS and observed latitude and longtitude values on teseo suite chart. charts like below. I also added on the image real values which are blue lines: the values seemed a bit strange to me, quite far from the expected CEP values. What can be the reason, in a nutshell what should I do increase accuracy. I will be waiting for your recommendations.

Last question, If I increase fix rate from 1 sec to 5 sec, would this change affect the accuracy of positioning ?

  

[GalaxyQuest]

Hi,

Have you used a tool to visualize the spread of your points? Checkout a tool called NMEASTAT, you can upload your NMEA data and you can visualize your data. We are enabling this feature in TeseoSuite in an upcoming release.

Meanwhile on Teseo Toolbar, there is a "View Positioning" icon. You can enter your reference position and the tool will calculate CEP-50 values.

I used the distance between the maximum latitude difference and maximum longitude difference to determine spread of 2 points and the value I calculated is ~ 2m which is CEP-95 or CEP-99 measure. I know these points of the maximum variance that I used did not happen at the same time so your spread of fixes is smaller than that.

To get most optimal performance / GNSS accuracy make sure you have clear view of sky and no chance of multipath. Increasing fix rate from 1 sec to 0.5 sec is not going to increase accuracy by GNSS but you can use statistical means to ascertain accuracy since you have more data points.