[Top][All Lists]
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [Discuss-gnuradio] ptime get_time(void) precision down to millisec m
From: |
Bastien Auneau |
Subject: |
Re: [Discuss-gnuradio] ptime get_time(void) precision down to millisec microsec nanosec ? |
Date: |
Thu, 19 May 2011 17:07:25 +0000 |
User-agent: |
Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9.2.17) Gecko/20110414 Lightning/1.0b2 Thunderbird/3.1.10 |
Hi
I think there is a misunderstanding.
I do not want to set the time of the USRP.
I want to use the USRP (with GPSDO) as my time reference.
This is why I want to query the USRP using the UHD function ptime
get_time(void) in
/host/lib/usrp/gps_ctrl.cpp @ line 133
This function only returns date and time down to seconds, and the
toked[] array has a bigger length than what is used :
"
UHD_ASSERT_THROW(toked.size() == 12); //if it's not we got something
weird in there
now = ptime( date(
greg_year(boost::lexical_cast<int>(toked[9].substr(4, 2)) + 2000),
//just trust me on this one
greg_month(boost::lexical_cast<int>(toked[9].substr(2, 2))),
greg_day(boost::lexical_cast<int>(toked[9].substr(0, 2)))
),
hours( boost::lexical_cast<int>(toked[1].substr(0, 2)))
+ minutes(boost::lexical_cast<int>(toked[1].substr(2, 2)))
+ seconds(boost::lexical_cast<int>(toked[1].substr(4, 2)))
);
"
So I would like to know the format of the string returned by the
safe_gps_read(); function,
"
reply = safe_gps_read();
"
or better the description of the toked[] array after it get through
"
tok.assign(reply);
toked.assign(tok.begin(), tok.end());
"
Bastien
On 2011-05-19 14:46, Josh Blum wrote:
>
>> Is it possible to extract from the reply the milli ? micro ? and nano
>> seconds ? For example using toked[2-8] or toked[10-11] (because
>
> I recommend that you use query the seconds to catch the PPS edge, and
> then set the time for the next PPS. This will set the GPSDO time into
> the device at the precision of a clock cycle:
>
> http://www.ettus.com/uhd_docs/doxygen/html/classuhd_1_1usrp_1_1multi__usrp.html#aaa80cd6ee4b3c1bf52afb9c3ef02f64d
>
> -Josh
>