Get GPS time from GPSDO module

GNU Radio
1

Hi All

I cannot find in latest version (downloaded the 28/07/2011) how to get
UTC time from GPSDO.

There used to be a get_time() function in gps_ctrl, but not anymore
How should I do to get GPS time ?

Regards
Bastien

2

On Thu, 2011-07-28 at 19:03 +0000, Bastien Auneau wrote:

Hi All

I cannot find in latest version (downloaded the 28/07/2011) how to get
UTC time from GPSDO.

There used to be a get_time() function in gps_ctrl, but not anymore
How should I do to get GPS time ?

The mboard_sensors interface should be used.
get_mboard_sensor(“gps_time”) should get you what you’re looking for.

–n

3

I use :
uhd::sensor_value_t val = usrp->get_mboard_sensor(“gps_time”);
std::cout << val.to_pp_string() << std::endl;

I got first an unhandled exception runtime error
at second run, it outputs :
GPS time: 2077252342 seconds

and these two in a row at each try

Also, the value returned 2077252342 never increase
And I did not plug the GPS antenna, so the GPSDO is not locked

How can I get is stable ?
Why runtime error pops up half of the time ?
should I plug the antenna and wait for GPS lock ?
How do I check if GPS is locked ?

4

On Thu, 2011-07-28 at 20:13 +0200, Bastien Auneau wrote:

and these two in a row at each try

Also, the value returned 2077252342 never increase
And I did not plug the GPS antenna, so the GPSDO is not locked

How can I get is stable ?
Why runtime error pops up half of the time ?
What runtime error are you seeing? Please cut and paste the error.

should I plug the antenna and wait for GPS lock ?
Only if you really care what time it is.

How do I check if GPS is locked ?
get_mboard_sensor(“gps_locked”)

–n

5

In case previous email with attached screenshot did not work
run-time error
Unhandled exception at 0x759ab9bc in TE.exe: Microsoft C++ exception:
uhd::runtime_error at memory location 0x0018db9c…

code :
uhd::sensor_value_t val = usrp->get_mboard_sensor(“gps_time”);
std::cout << val.to_pp_string() << std::endl;

It gives unhandled exception at first line
And I realized that the exception happen every time, and after
continuing
(because VC9 breaks on unhandled exception) it gives this all same value
:
GPS time: 2077252342 seconds

6

uhd::sensor_value_t val = usrp->get_mboard_sensor(“ref_locked”);
works fine, no runtime error

uhd::sensor_value_t val = usrp->get_mboard_sensor(“gps_locked”);
gets runtime error just like gps_time

7

On Fri, 2011-07-29 at 01:07 +0200, Bastien Auneau wrote:

uhd::sensor_value_t val = usrp->get_mboard_sensor(“ref_locked”);
works fine, no runtime error

uhd::sensor_value_t val = usrp->get_mboard_sensor(“gps_locked”);
gets runtime error just like gps_time

yeah, that’s weird, shouldn’t be happening. i’ll look into it.

–n

8

Hi Nick

We have compiled (in debug mode) the last UHD (3.2.1)
Now there are no “unhandled exception” while querying the sensors
I guess I made a mistake with release/debug mode earlier

Also, I understood that I have to build UHD in debug mode, and that I
cannot use the binary version for windows, while my project using UHD is
on debug mode ? Please confirm/infirm

Also, in case of missing msvcp100.dll, installing Visual C++
redistribution package helps only if you install the x86 (32 bit)
version. Hope this will help someone…

Regards
Bastien

9

Screenshot-1
code
Screenshot-2
successful run
Screenshot-3
runtime error