Db820c : GPS not working on linux

Any update on GPS support on Dragonboard 820c?

unfortunately, no. all the drivers and user space are “in place”, but it’s not working, and we haven’t investigated further (and are not planning to investigate in the very short term).

Thanks @ndec. I will try to investigate it.

I’m noticing that the pds patch for gpsd is over a year old, and hasn’t made it upstream yet. What’s the hold up? I’ve been working with gpsd upstream for just a few days now, and I’m finding them to be extremely responsive. They’ve already merged several patches that I’ve provided to them for supporting Android.

I think part of the reason is that the code does not work as expected on 820C.

I have been working with linux based system, and the file system is from
And I do have installed:
qrtr-apps gnss-gpsd qdsp-config

Being new to GPS framework,need some help on how to fix:
$ systemctl start qdsp-start.service
Failed to start qdsp-start.service: Unit qdsp-start.service not found.

CGPS & GPSMON didnt print NMEA strings…
Is there anything I’m doing wrong?? Any reference/reading suggestions?? Thanks…

I’m afraid the situation hasn’t changed since Apr 1:

In other words the components needed for GPS have been enabled in the Debian snapshot images but are known not to be working.

Thanks @danielt, will continue to debug from my perspective…
Please do update if you find them(cgps & gpsmon) working.

Any update on GPS in DB820c Debian?
Can someone give pointers to debug this further?



Hello Team,

Any update on GPS in DB820c?



Any update on GPS support on Dragonboard 820c?

AFAIK, there is no plan for now.

I have tried to rebuild gpsd & after having replaced all new set of binaries (gpsd,cgps,gpsmon the systemd service & socket file also lib*.so files) to respective locations.
I found that in gpsd.service:


But there is no such service:

systemctl status chronyd
Unit chronyd.service could not be found.

Is it the error causing gpsd service not to function properly??
I even tried reloading service with:

This loaded /usr/bin/gpsd , still no luck with NMEA strings…
Any suggestions ?? Thanks in advance…

Hi all,

I have obtained NMEA strings working :smiley: with the updates in gpsd…
Its taking 10-20min to get proper location fix for first time. Until then it prints only PRN’s (noises).
The concerns I have are regarding effectiveness…

  1. Does gpsd have any methods to improve accuracy like in Android ?
  2. Are there any other daemons to test NMEA strings having GPS location ? (tried gpsmon, xgps & cgps all of these work on gpsd & take longer time to get location fix)…

There is nothing in Android that will improve the accuracy of GPS data.
Speed, perhaps, since most GPS HALs in Android will implement AGPS to reduce the time it takes to get a first fix, but the accuracy itself will be unaffected.

Without some kind of assistance data, 10-20 minutes for first fix seems like it could be perfectly reasonable, especially if the conditions are less than ideal, such as using a passive PCB antenna, or trying to use it from inside a building.

The last time I looked deeply at gpsd (several months ago when I wrote its Android HAL, which you will now find in gpsd’s android/ path), it didn’t implement any form of AGPS.

Hi, @ymj

I am also trying GPS with Debian (http://snapshots.linaro.org/96boards/dragonboard820c/linaro/debian/384/) release but have no success. I followed below steps:

sudo apt-get update
sudo apt-get install gnss-gpsd
sudo apt-get install qdsp-start

systemctl start gpsd
gpsdctl add /dev/ttyGPS0
gpsdctl add pds://any


gpsmon output:

tcp://localhost:2947          JSON slave driver>
(82) {"class":"VERSION","release":"3.17","rev":"3.17","proto_major":3,"proto_min
(172) {"class":"DEVICES","devices":[{"class":"DEVICE","path":"/dev/ttyGPS0","act
(122) {"class":"WATCH","enable":true,"json":false,"nmea":false,"raw":2,"scaled":

Below is the output of Required service status:

root@linaro-alip:~# systemctl status qdsp-start
● qdsp-start.service - Start the Hexagon QDSP
Loaded: loaded (/lib/systemd/system/qdsp-start.service; enabled; vendor prese
Active: inactive (dead) since Mon 2019-11-11 10:45:35 UTC; 23min ago
Process: 2137 ExecStart=/usr/sbin/qdsp-start (code=exited, status=0/SUCCESS)
Main PID: 2137 (code=exited, status=0/SUCCESS)

root@linaro-alip:~# systemctl status gpsd
● gpsd.service - GPS (Global Positioning System) Daemon
Loaded: loaded (/lib/systemd/system/gpsd.service; disabled; vendor preset: en
Active: active (running) since Mon 2019-11-11 11:11:15 UTC; 2s ago
Process: 2712 ExecStart=/usr/sbin/gpsd $GPSD_OPTIONS $DEVICES (code=exited, st
Main PID: 2713 (gpsd)
Tasks: 1 (limit: 4445)
Memory: 1000.0K
CGroup: /system.slice/gpsd.service
└─2713 /usr/sbin/gpsd

root@linaro-alip:~# systemctl status gpsd.socket
● gpsd.socket - GPS (Global Positioning System) Daemon Sockets
Loaded: loaded (/lib/systemd/system/gpsd.socket; enabled; vendor preset: enab
Active: active (listening) since Mon 2019-11-11 10:45:34 UTC; 25min ago
Listen: /var/run/gpsd.sock (Stream)
[::1]:2947 (Stream) (Stream)
CGroup: /system.slice/gpsd.socket

What am i missing something here? can you please tell me what steps you followed to start GPS


The NMEA strings where obtained after a lot of trials. According to me, major change I had to do was:

  1. To clone in latest gpsd sources which has pds support. Replace them with existing gpsd & gpsdctl.
  2. To test in proper environment(clear space) which helps by a large-factor.

I believe that guys in this forum had done a great job in helping me throughout. I have no idea why qpsd-start service is used,so forum members should be right people to solve the queries.Thanks…


i tried this release http://snapshots.linaro.org/96boards/dragonboard820c/linaro/debian/384/

i do not see this device in my build , please suggest

root@linaro-alip:~# ls /dev/tty
tty tty18 tty28 tty38 tty48 tty58 ttyMSM0 ttypa
tty0 tty19 tty29 tty39 tty49 tty59 ttyp0 ttypb
tty1 tty2 tty3 tty4 tty5 tty6 ttyp1 ttypc
tty10 tty20 tty30 tty40 tty50 tty60 ttyp2 ttypd
tty11 tty21 tty31 tty41 tty51 tty61 ttyp3 ttype
tty12 tty22 tty32 tty42 tty52 tty62 ttyp4 ttypf
tty13 tty23 tty33 tty43 tty53 tty63 ttyp5 ttyS0
tty14 tty24 tty34 tty44 tty54 tty7 ttyp6 ttyS1
tty15 tty25 tty35 tty45 tty55 tty8 ttyp7 ttyS2
tty16 tty26 tty36 tty46 tty56 tty9 ttyp8 ttyS3
tty17 tty27 tty37 tty47 tty57 tty96B1 ttyp9
root@linaro-alip:~# ls /dev/tty



i am trying to build gpsd , but it is failing, please suggest


sudo apt remove gnss-gpsd
git clone https://github.com/andersson/gpsd
cd gpsd
sudo apt-get install python-dev scons -y
scons && scons check && sudo scons udev-install


Try older snapshots : like 362 in my case.
Are you able to sucessfully install : sudo apt-get install python-dev scons -y
Put in complete logs for overall steps followed.