looking for a gps module with $GPZDA (date and time) - Page 1
Forum section: electronics / general

author: legacy
author_rank: Super Contributor
timestamp: March 02, 2019, 10:03:01 pm
content: so I have recently bought anMP-954GPSmodule(1), which comes with a GPS module onboard, but it doesn't output any GPZDA packet. The GPZDA packet mainly shows time and date (year, month, and day).Does anyone know a GPS module known for providing the ZDA?Thanks(1) manuals do not help because they do not not clearly report exactly WHAT is implemented.

author: legacy
author_rank: Super Contributor
timestamp: March 02, 2019, 10:19:51 pm
content: thisarticle suggests that it might be possible to enable ZDA sentence

author: georges80
author_rank: Frequent Contributor
timestamp: March 02, 2019, 10:32:18 pm
content: I have a ublox 8 module. By default it does not output that sentence. But using the ublox u-center software I just went and enabled it. Checked the serial nmea stream and it DOES now get output.So, at the very least ublox 8 supports it. I'll see if the ublox 6 I also have can be set to output the sentence. Give me 10 - 20 mins to check.cheers,george.

author: georges80
author_rank: Frequent Contributor
timestamp: March 02, 2019, 10:46:31 pm
content: ok, can enable the zda sentence on the ublox 6 as well.cheers,george.

author: legacy
author_rank: Super Contributor
timestamp: March 03, 2019, 12:13:41 pm
content: thanks

author: legacy
author_rank: Super Contributor
timestamp: March 03, 2019, 12:20:46 pm
content: I wonder if also SiRF Star III GPS modules can enable the ZDA sentenceCannot find any documentation about.

author: Wiljan
author_rank: Regular Contributor
timestamp: March 03, 2019, 02:43:39 pm
content: If it's a SiRF Star III you should be able to send a cmd to tell the module what to send to youhave a look herehttps://www.sparkfun.com/datasheets/GPS/NMEA%20Reference%20Manual-Rev2.1-Dec07.pdfon page 103 you can see that you can change the Query eg RMC does give you "Time, date, position, course and speed data"I did made Numitron clock long time ago usinghttps://www.adafruit.com/product/746GPS module and when you have the data you have to calculate the current day and when to change summer/ winter time since there are no flag to indicate daylight saving

author: gamblingfetus
author_rank: Newbie
timestamp: March 03, 2019, 10:42:25 pm
content: Yes, the ADA746 supports GPZDA unofficially if you sweet talk it. I had to basically rewrite their library to use it for an automatically-setting GPS clock project.

author: legacy
author_rank: Super Contributor
timestamp: March 04, 2019, 01:22:25 pm
content: now the question is: will my Sirf-III miniPCI GPS work with ZDA, or will have to buy a new GPS (and a new miniPCI multi Uart card, since I need 3 Uart channels for other stuff)?It seems my GPS is not willing to enable the ZDA sentence

author: legacy
author_rank: Super Contributor
timestamp: March 04, 2019, 01:35:55 pm
content: Quote from: gamblingfetus on March 03, 2019, 10:42:25 pmlike in oursonokoproject.Quoteso it's a bit weird that a modern GPS doesn't provide the ZDA sentence by default

author: Wiljan
author_rank: Regular Contributor
timestamp: March 04, 2019, 06:53:11 pm
content: So to understand it correctly you do have the PCI card in a PC and then it turns up as 3 com port in the control-panel?2 of the port are "just" on the 2x 9pin D-sub and have noting to do with the GPS?and 1 are connected to the SiRF II module on board and this is the one giving you a 4800 GPS data?When you try to send data to the SiRF III module and described in the SiRF pdf I linked to doe you get any respond ? Can you change simple things like the rate where that data are send or other things?I would expect all SiFR III chipsset to respond likely but I can be wrong

author: legacy
author_rank: Super Contributor
timestamp: March 04, 2019, 08:07:28 pm
content: System diagram about our Sonoko project; see the router (rb532) needs 4 serial lines, one of them is reserved for the onboard GPS, which is soldered to the miniPCI card.Quote from: Wiljan on March 04, 2019, 06:53:11 pmWe are using a router, with a miniPCI multi uart cards./dev/ttyS0 is the router-built-in serial (it's the router's console, cannot be used)/dev/ttyS1 is reserved for the miniPCI-built-in GPS/dev/ttyS2 is reserved for talking with node0/dev/ttyS3 is reserved for talking with node1/dev/ttyS3 is reserved for talking with an engine that controls a display, an RFID reader and other stuff (not currently shown in the system diagram, still under development)Quote from: Wiljan on March 04, 2019, 06:53:11 pmPrecisely. No response. Probably the command it's not supported, in fact, the pdf says "you can enable ZDA only if PPS is supported", and in our case ... there is no "PPS" signal.Quote from: Wiljan on March 04, 2019, 06:53:11 pmyes, we are using 1200bps instead of 4800bps: this was changed by issuing a command on the serial line, and the GPS accepted it.Quote from: Wiljan on March 04, 2019, 06:53:11 pmchanging the baud rate was silent, without any feedback on the serial line: it just started talking at 1200bps.

author: Wiljan
author_rank: Regular Contributor
timestamp: March 04, 2019, 09:49:31 pm
content: Is this the string you try to send?$PSRF103,00,08,00,01*2Cmode 08 = ZDAI believe the chksum should be 2C