[Ovmsdev] Time variable
Mark Webb-Johnson
mark at webb-johnson.net
Thu Nov 7 14:27:06 HKT 2019
Like this (experiment):
$ ./t.pl
UTC original = Wed Mar 22 20:28:27 2000
UTC adjusted = Wed Nov 6 20:28:27 2019
$ cat t.pl
#!/usr/bin/perl
use POSIX qw(strftime);
use Time::Local;
my @original = (27,28,20,22,3-1,2000-1900,0);
print "UTC original = ", strftime("%a %b %e %H:%M:%S %Y", at original),"\n";
my $jdt = timegm(@original);
my $ajdt = $jdt + (1024 * 7 * 86400);
my ($sec,$min,$hour,$mday,$mon,$year,$wday,$yday,$isdst) = gmtime($ajdt);
print "UTC adjusted = ", strftime("%a %b %e %H:%M:%S %Y",($sec,$min,$hour,$mday,$mon,$year,$wday,$yday,$isdst)),"\n";
@Tamás: Does the above adjustment show the correct date/time (Wed Nov 6 20:28:27 2019 UTC)?
Regards, Mark.
> On 7 Nov 2019, at 2:13 PM, Mark Webb-Johnson <mark at webb-johnson.net> wrote:
>
>
> The issue is that we don’t have week numbers from the GPS (and presumably week to date is non-trivial).
>
> We get the date/time from the NMEA RMC message, then pass it into this to convert to a julian date/time:
>
> /**
> * utc_to_timestamp:
> * convert GPS date & time (UTC) to timestamp
> * date: "ddmmyy"
> * time: "hhmmss"
> */
> static unsigned long utc_to_timestamp(const char* date, const char* time)
> {
> int day, month, year, hour, minute, second;
>
> day = (date[0]-'0')*10 + (date[1]-'0');
> month = (date[2]-'0')*10 + (date[3]-'0');
> year = (date[4]-'0')*10 + (date[5]-'0');
>
> hour = (time[0]-'0')*10 + (time[1]-'0');
> minute = (time[2]-'0')*10 + (time[3]-'0');
> second = (time[4]-'0')*10 + (time[5]-'0');
>
> return
> (JdFromYMD(2000+year, month, day) - JDEpoch) * (24L * 3600)
> + ((hour * 60L + minute) * 60) + second;
> }
>
> Perhaps sufficient to add 1024 * 7 * 86400 to that?
>
> Regards, Mark.
>
>> On 7 Nov 2019, at 1:44 PM, Stephen Casner <casner at acm.org <mailto:casner at acm.org>> wrote:
>>
>> Mark,
>>
>> You don't need the condition "date <2019-11-03", just always add 1024
>> weeks to the current time value coming from the modem.
>>
>> -- Steve
>>
>> On Thu, 7 Nov 2019, Mark Webb-Johnson wrote:
>>
>>> Damn:
>>>
>>> https://www.cika.com/soporte/Information/GSMmodules/GPS-week-rollover_Simcom.pdf <https://www.cika.com/soporte/Information/GSMmodules/GPS-week-rollover_Simcom.pdf> <https://www.cika.com/soporte/Information/GSMmodules/GPS-week-rollover_Simcom.pdf <https://www.cika.com/soporte/Information/GSMmodules/GPS-week-rollover_Simcom.pdf>>
>>>
>>> I think we can do a fix in the SIMCOM module that if the date <2019-11-03 then offset it somehow? Any ideas?
>>>
>>> Regards, Mark.
>>>
>>>> On 7 Nov 2019, at 1:09 PM, Stephen Casner <casner at acm.org <mailto:casner at acm.org>> wrote:
>>>>
>>>> This page mentions the problem:
>>>>
>>>> https://techship.com/news/gps-week-roll-over-issue-during-epoch-restart/ <https://techship.com/news/gps-week-roll-over-issue-during-epoch-restart/>
>>>>
>>>> Quoting there:
>>>>
>>>> For the Qualcomm MDM9x15 series (4G/LTE Cat 3) and MDM6200
>>>> (3G/HSPA+) series chipsets there is a offset used, so the GPS week
>>>> roll over will occur 1054+1023 weeks since launch of the GPS, and
>>>> more precisely in beginning of November 2019 (UTC 23:59:42
>>>> November 2, 2019)
>>>>
>>>> [snip]
>>>>
>>>> 3G/HSPA+ modules based on Qualcomm MDM6200 series chipsets:
>>>> Huawei EM820W / MU609 series
>>>> Telit DE910 series
>>>> Simcom SIM5320 series
>>>>
>>>> This sounds like the hardware/firmware won't be fixed. Perhaps the
>>>> solution for OVMS is just to put an offset as a workaroud. That will
>>>> work for the next 1024 weeks.
>>>>
>>>> -- Steve
>>>>
>>>> On Wed, 6 Nov 2019, Stephen Casner wrote:
>>>>
>>>>> Sorry, I did not read carefully. The item you mentioned is just an
>>>>> antenna. The GPS implementation is in the modem module, correct?
>>>>> That's where the correction is needed.
>>>>>
>>>>> -- Steve
>>>>>
>>>>> On Thu, 7 Nov 2019, Tamás Kovács wrote:
>>>>>
>>>>>> I use a universal gps connected to ovms, not the car own gps. (
>>>>>> https://www.fasttech.com/products/1020200)
>>>>>>
>>>>>> Stephen Casner <casner at acm.org> ezt írta (időpont: 2019. nov. 7., Cs, 0:42):
>>>>>>
>>>>>>> Tamás,
>>>>>>>
>>>>>>> This looks like the GPS sensor did not handle the rollover of the
>>>>>>> 10-bit week-number field in April, 2019. So the timestamps are off by
>>>>>>> 1024 * 7 * 24 * 60 * 60 seconds. Here is the US government alert about
>>>>>>> this problem:
>>>>>>>
>>>>>>>
>>>>>>> https://www.us-cert.gov/sites/default/files/documents/Memorandum_on_GPS_2019.pdf
>>>>>>>
>>>>>>> This problem was recently discovered for the Garmin GPS 18x LVC
>>>>>>> sensors in the Tesla Roadster 2.5 (but not in the earlier 1.5 version
>>>>>>> like I have, which has the older GPS 18 LVC sensor):
>>>>>>>
>>>>>>>
>>>>>>> https://teslamotorsclub.com/tmc/threads/caution-annual-service-car-power-down-gps-issue.163328/
>>>>>>>
>>>>>>> There is a firmware update to fix this for the GPS 18x LVC. Perhaps
>>>>>>> there is one for the GPS sensor in the Mitsubishi as well.
>>>>>>>
>>>>>>> -- Steve
>>>>>>>
>>>>>>> On Wed, 6 Nov 2019, Tamás Kovács wrote:
>>>>>>>
>>>>>>>> I have a problem with utc time, the time is correct but the date is not
>>>>>>>> valid. I use 3.2.005-99-g88cfeef9 version with modification of Mitsubishi
>>>>>>>> i-MiEV.
>>>>>>>>
>>>>>>>> OVMS# me li utc
>>>>>>>> m.time.utc 953756768Sec
>>>>>>>> I (900675) housekeeping: 2000-03-22 21:27:06 CET (RAM: 8b=82812-86452
>>>>>>> 32b=27308)
>>>>>>>> I (981115) webserver: HTTP POST /api/execute
>>>>>>>> I (981115) webcommand: HttpCommandStream[0x3fa32958]: 1984428 bytes
>>>>>>>> free, executing: time
>>>>>>>> OVMS# time
>>>>>>>> Time Zone: CET-1CEST,M3.5.0,M10.5.0/3
>>>>>>>> UTC Time: 2000-03-22 20:28:27 UTC
>>>>>>>> Local Time: 2000-03-22 21:28:27 CET
>>>>>>>> Provider: gsm-nmea
>>>>>>>>
>>>>>>>> PROVIDER STRATUM UPDATE TIME
>>>>>>>> *gsm-nmea 2 0 Wed Mar 22 20:28:27 2000
>>>>>>>>
>>>>>>>>
>>>>>>>> --
>>>>>>>> Üdvözlettel:
>>>>>>>> Kovács Tamás_______________________________________________
>>>>>>> OvmsDev mailing list
>>>>>>> OvmsDev at lists.openvehicles.com
>>>>>>> http://lists.openvehicles.com/mailman/listinfo/ovmsdev
>>>>>>>
>>>>>>
>>>>>>
>>>>>> --
>>>>>> Üdvözlettel:
>>>>>> Kovács Tamás
>>>> _______________________________________________
>>>> OvmsDev mailing list
>>>> OvmsDev at lists.openvehicles.com
>>>> http://lists.openvehicles.com/mailman/listinfo/ovmsdev
>>>
>> _______________________________________________
>> OvmsDev mailing list
>> OvmsDev at lists.openvehicles.com <mailto:OvmsDev at lists.openvehicles.com>
>> http://lists.openvehicles.com/mailman/listinfo/ovmsdev
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.openvehicles.com/pipermail/ovmsdev/attachments/20191107/64ad453f/attachment.html>
More information about the OvmsDev
mailing list