Teseo-liv3f (Astra1b) can't find any sattelites

Gregor14 · ‎2026-04-14

Hi to everybody,

I have a annoying problem with Teseo-liv3f (on Astra1B). It can not find any sattelites. What I have:

1. Chip is build in dev kit from STM Astra1B, so there is no problem with layout, wrong antenna, etc.

2. I'm using as reference hex files from example project provided by STM: "CustomUC"

3. Kit is placed under sky, so it can see sattelites.

4. I have 3 pcs. of such kit, both can't see sattlites

5. On all devices, I program (at the beginning) my compilation of my firmware. When I realise that it can't see sattelites, I reprogram then flash by hex delivered by STM (CustomUC). Still can't see sattlites (I'm using on console command !gnssreport-on). Maybe during programming my version of firmware, I damaged some configuration bytes??

6. I though that maybe amplifier on gps antenna is off (ANToff pin13), but there is 3.3V, so seems to be OK.

7. Now, I detach on one device TX and RX of Teseo-liv3F, and I connect them (through serial / usb converter) to computer. I'm using now Teseo-Suite. I see logs, I try to reconfigure low power mode, used contellations, etc. No luck. Teseo is reconfigured, but still no sattelites.

8. I have also other gps module (Ublox Neo-7m). It works, even inside room, so this is not problem of "noisy environment".

9. I fulfill all reccomendation from this thread: STEVAL-ASTRA1B - Teseo-LIV3F GNSS Not working - STMicroelectronics Community

10. I read in Teseo-Suite Pro all info about version of Teseo. Here it is:

OS20LIB_4.3.0_ARM

GPSAPP_2.4.0.2_ARM

BINIMG_4.6.8.2_ARM

SWCFG_82045325

WAASLIB_2.20.0_ARM

STAGPSLIB_6.0.0_ARM

STA8090_822bc043

GNSSLIB_8.4.10.16.3_ARM

Maybe sombody have any clue, what I do wrong? Broken 3 devices, I doubt it. Rather I set wrong some jumpers or during programming I made some mistake.

Any clues are welcome.

Thank you in advance,

Gregor

GalaxyQuest · ‎2026-04-15

@Gregor14 wrote:

7. Now, I detach on one device TX and RX of Teseo-liv3F, and I connect them (through serial / usb converter) to computer. I'm using now Teseo-Suite. I see logs, I try to reconfigure low power mode, used contellations, etc. No luck. Teseo is reconfigured, but still no sattelites.

Just to confirm, if you connect the UART lines from LIV4F module, can you see the NMEA data coming out ? If you can see data, can you please log the data in Teseo Suite and attach it here?

Secondly, I see that TP100 is PPS, test point. Can you please probe the line and see if you are getting a 1 PPS output with 50% duty cycle?

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Gregor14 · ‎2026-04-15

Yes, I can communicate in "Teseo Suite Pro" with liv3f. Module constantly sending $GPRMC and $GPGGA. Below I attached part of log when I in addition ask module for "Version Information".

$GPRMC,000240.000,V,0000.00000,N,00000.00000,E,0.0,0.0,030917,,,N*7C
$GPGGA,000240.000,0000.00000,N,00000.00000,E,0,00,99.0,100.00,M,0.0,M,,*6A
$GPTXT,DEFAULT LIV CONFIGURATION*2B
$PSTMVER,OS20LIB_4.3.0_ARM*47
$PSTMVER,GPSAPP_2.4.0.2_ARM*06
$PSTMVER,BINIMG_4.6.8.2_ARM*09
$PSTMVER,SWCFG_82045325*61
$PSTMVER,WAASLIB_2.20.0_ARM*6A
$PSTMVER,STAGPSLIB_6.0.0_ARM*5A
$PSTMVER,STA8090_822bc043*61
$GPTXT,(C)2000-2011 ST Microelectronics*20
$GPTXT,DEFAULT LIV CONFIGURATION*2B
$PSTMGETSWVER,255*17
$PSTMVER,GNSSLIB_8.4.10.16.3_ARM*5E
$PSTMGETSWVER*09
$GPRMC,000241.000,V,0000.00000,N,00000.00000,E,0.0,0.0,030917,,,N*7D
$GPGGA,000241.000,0000.00000,N,00000.00000,E,0,00,99.0,100.00,M,0.0,M,,*6B
$GPRMC,000242.000,V,0000.00000,N,00000.00000,E,0.0,0.0,030917,,,N*7E

About PPS signal. Yes, although I have 0 satellites, on TP100 I see 1Hz signal with 50% duty.

In this moment I put module near window, where still antenna "can see sky (through glass)". Module work since ~20min, still 0 sattelites.

GalaxyQuest · ‎2026-04-15

Hi,

Having PPS and seeing the messages is a good indication your module is outputting data and working correctly.

You said you placed near a window. Can you please take the module outside? Office windows can have coating that prevents reception of GNSS signal.

Also make sure the antenna side of the board is facing the sky.

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Gregor14 · ‎2026-04-15

Ok, I put device outside. Sky was directly visible. It work for 33 minutes, then I stopped it. Result was same (I mean: 0 satellites). Last lines in log:

$GPRMC,003649.000,V,0000.00000,N,00000.00000,E,0.0,0.0,030917,,,N*72
$GPGGA,003649.000,0000.00000,N,00000.00000,E,0,00,99.0,100.00,M,0.0,M,,*64

Let me note, I made test ouside office, few days ago, with other Astra1B (without any hardware changes and then I just read info in console, thanks to command !gnssreport-on). Result was same.

Maybe there was in past, some problems in production with antenna path (amplifier, RC, filter, etc)?

GalaxyQuest · ‎2026-04-16

Hi,

I am checking with team who maintains the ASTRA1B board about this. I will let you know when I have a response.

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Gregor14 · ‎2026-04-21

Do you have any news concern to this matter?

GalaxyQuest · ‎2026-04-21

As you can see from the schematics we provide you additional antenna connectors but these are under the existing patch antenna. Therefore, can you desolder the existing antenna and connect an external antenna?

We have provided SMA footprint and u.FL connector.

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GalaxyQuest · ‎2026-04-24

Hi,

I wanted to check if you have made any progress on debugging the ASTRA1B problem.

Instead of removing the antenna, maybe as a less invasive option, can you also try bypassing the LNA and SAW filter? I am attaching the picture showing the location of bypass resistor pads R104 and R105

Here is the schematic https://www.st.com/resource/en/schematic_pack/steval-astra1b_schematic.pdf

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Gregor14 · ‎2026-04-29

I did this change (caps removed, jumpers added) on one Astra. It stay under sky through ~1hour. Still 0 sattelites. I do not see on scheamtic any jumpers or switches that can corrupt reading gps, this is (IMHO) also dead end.

I set module by follownig commands:

$PSTMRESTOREPAR

$PSTMSETPAR,1201,00000042

$PSTMCFGCONST,1,0,1,1,1

$PSTMSAVEPAR

$PSTMSRR

It wasn't helpful. I added to code (based on CustomUC) printing on USB console data that Teseo sending to STM32WB. I see continously $GPRMC (with value "V" in Status field) and $GPGGA, so there is communication.

5cm apart to Astra is placed now quectel. It see now 6 valid sattelites.

There is last idea. Prevoius user of Astras, probably use following command

$PSTMSETPAR,1202,7.

For me it seems wrong (NCO max range). That's why I use $PSTMRESTOREPAR to restore there value=0 (automatic adjusting). Do you think that, there could be any problem?