Navilock 8004u GNSS device

Rainer Plattner shared this problem 21 months ago

Hi folks,

wanna connect a USB GPS NL8004u via sensormanager

it shows:

u-blox GNSS receiver

u-blox AG

-vendor: 5446

-product: 424

but there is no connection button!

I'm using Android 10 on Hanspree Tablett, the gps connector app shows acurate position data, but locus does seem to recognize the gps mouse.

any help would be appreciated

Replies (3)


Hello Rainer,

may you please post a screenshot of what you see on the screen? Thanks.


as requested a screenshot


Hello Rainer,

thanks for the additional info. I can't guarantee, but most probably your device will work in the next app versions (probably middle of September). After the update, give it a try, and please let me know if there will be any problems. Thanks.


After Update locusmap in October Navilock 8004u is correct identified and locusmap is connecting => great!

After some testing there are two major problems

  • locusmap loses connection after 1min and does repeating this behavior for quit some time until it is stable for about 5-10min, then the circle starts again (tablet at the same position)
    - as there is no autoconnection available you have to push the Connect button 10to15 times
  • the 8004u supports these frequenzes
    • Frequenz:
    GPS: L1, 1575,4200 MHz
    GLONASS: L1, 1602 (k x 0,5625) MHz
    BEIDOU COMPASS: B1, 1561,0980 MHz
    GALILEO E1, 1575,4200 MHz
    QZSS L1, 1575,4200 MHz
    but shows only GPS & GLONASS in locusmap => we would prefer GPS & Galileo

any idea????



thanks for the tests. Does your device disconnect even when the screen is still turned on the whole time?

About missing data: may you please enable in the app GPS settings, recording of the NMEA messages? Then try to use your device for a while. After that, the Locus/data/NMEA directory should be a newly recorded file with data, which may help me to check this issue. Thanks.



sorry for the delay, but i found time to generate the data file - i hope it has enough information, i have a bigger one but it's over 2mb, so i couldn't load it up

And for your question: Yes it disconnects while using locusmap and to clarify not disconnecting the USB connection just losing the signal from the GPS mouse

thx for your support


Hello Rainer,

thanks for the NMEA file. If you look inside, satellites are reported thanks to "GSV" messages. Two letters before this define source. As you may see, only "GPGSV" (Navstar) and "GLGSV" (Glonass) are inside. There is no "GAGSV" message (Galileo), so the result visible in the app is correct. If your device supports more sources, they seems not to be reported over NMEA messages.


Hi Menion,

took some time but we make progress!

With the u-blox receiver software i changed Galileo to Active and nmea Standard to 4.1 => with great success in locusmap!

That leaves one annoying problem, the gps is disconnected very 60Sec, after some checking this are my current parameters

-Android position ON and authorization => always for locusmap

- Sensor Manager: GPS on on start App

- Sensor Manager: GPS finding deactivated = OFF

- Sensor Manager: GPS Auto-off = OFF

the whole story generates two popups:

- bottom screen messages /usb/.... disconnected

- after some time 10-15Seconds => popup Allow locusmap to connect to u-blox external receiver....

necesary to hit OK Button

any ideas??


Hi Menion,

there is good news, your hunch was right, the gps mouse didn't send Galileo data, i had to correct some config parameters with the u-blox flash utility.

- Now we have GPS & Galileo as main receiver frequencies

- i changed to NMEA Standard 4.1

locusmap shows 17/21 satellites on my home position.

This leaves us with the last issue:

- the connection to the external mouse is disconnected every 60sec, which leads to a reconnecting with a popup box

I looked in the android and locusmap parameters:

- Android: locusmap is allowed for location always on => therefore it shouldn't ask erverytime for connection to gps mouse

- locusmap /gps&sensors: on start gps always on

- locusmap / gps deactivate: off

- locusmap/gps-auto off: off

any idea why the connection is still lost?

kind regards


Hello Rainer,

thanks for the tests and I'm also glad you've found a solution on your side!

About disconnecting: did you try a new version published yesterday? There was a minor fix that should help here.


Hello Menion,

there is progress and 1hour of testing reveals new possibilities.

As i stated my installation is bothered with constant Popups for grant access to GNSS receiver!

This is was i found:

- after updating to new locusmap release from december the situation improved => now the connection loss is about 3-4min

- i recognized that on each reconnection there is a small message on the bottom of the screen which reads

..../bus/usb/001/008 on the next connection it reads the same just the last number jumps to 010, 012,014,...

- so it seems there is a reset from android to the gps mouse for any reason we do not know,

but as the number of the connection changes it seems that android for security reasons ask for "new" permission to access the USB device => hence there comes the popup

this seems a to be a "known situation" for programmers and also found one coding solution which discusses the generated

<code>UsbManager.requestpermission(); and how to solve it.

any idea to conquer this ?



hmm really interesting. App asks thanks to "UsbManager.requestPermission" method during the first connection. This is a popup that you should see and confirm. Why the path to the device changed and why mentioned popup is visible? Do not know, sorry.

Did you tried to connect your GNSS device to a different Android device? Maybe it is just a problem on a certain device.

Leave a Comment
Attach a file