Re: [time-nuts] Sure Electronics GPS card, Linux quirk
The CP2102 is featured in Chinese ebay 4 buck usb-232 adapters. The chip suffers from serious bad-driveritis, and I've had to do 'net research to make it useful with various flavors of Windoze. Don Hal Murray I'm in the habit of using things like: cat /dev/ttyUSB0 when checking out GPS that I expect to send ASCII. When I tried that with my new toy, it went bonkers. In particular, the firmware LED went on, and the NMEA LED switched from blinking to solid on. The data included the stuff I expected, but it also included a lot of garbage. I (finally) tracked that down to echo being set on the tty parameters. That echos a copy of each input character back to where it came from. The cure is as simple as: stty -F /dev/ttyUSB0 -echo Of course, there are other ways to get in trouble with tty parameters. Here is the line I have stashed away in my notes on how to set things up: stty -F /dev/ttyxxx 9600 igncr clocal -echo -ixon Now that I've got that sorted out, it responds to the $PTMKxxx commands. (I've only tried one.) The Sure card uses the ST CP2102 USB to serial chip. It's not very common, but there is a Linux driver for it. I assume the default bits somewhere in the driver are different from defaults in the FTDI FT23x and the Prolific PL230x chips that are quite common. I haven't looked at the source code. In my quest for a low cost, no-soldering GPS gizmo that works well with NTP, I tried a Transystem GM-2. It had the same sort of garbage. That was a while ago. I gave up and put it on the back burner. Guess what. It uses the same USB-serial chip. It's working now. -- These are my opinions, not necessarily my employer's. I hate spam. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. -- Neither the voice of authority nor the weight of reason and argument are as significant as experiment, for thence comes quiet to the mind. R. Bacon If you don't know what it is, don't poke it. Ghost in the Shell Dr. Don Latham AJ7LL Six Mile Systems LLP 17850 Six Mile Road POB 134 Huson, MT, 59846 VOX 406-626-4304 www.lightningforensics.com www.sixmilesystems.com ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Sure Electronics GPS
Thanks for all the info. I wasn't aware that leapsecond did any testing on the unit. Now I gotta play more with it. Rix Seacord K2AVP Right, I ordered one too when the thread started in November. I just updated the lab report page to include 1PPS risetime and TTL/RS232 NMEA latency/jitter measurements: http://www.leapsecond.com/pages/MG1613S/ If there are any other questions about the unit, let me know off-line and I'll see what I can do while I still have it on the bench. /tvb ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Sure Electronics GPS
The SureElectronics unit is general within 10 feet with no observed off the wall excursions. With that in mind, I wonder how accurate is their 1pps output? Hi, There was some discussion on the MG1613S earlier. I ordered one off the bay and did a few test. I tried to post some pics of the PPS trace and my wiring mods and stats for those who might be interested but they didn't make it through the filters. Some details. The board is configured as an NMEA device and functions fine on all output interfaces available. You only get output at 9600 bps as standard and according to the manual it can only be configured otherwise through the serial interface. I didn't try changing it though. There is a nice GUI to monitor it. Works fine, but I haven't delved. Seems to allow sending NMEA commands so there may be some useful config changes possible. NMEA data output fixed at 9600bps, 8 bit, 1stop, no parity It is very sensitive, pulling in double the birds that I can regularly see from my unprivileged window sill , and also seems to be less sensitive to reflections than my motorola timing GPSs. That was good news as I have a big problem with the motorola receivers in that respect. The VP/UT+ are not able to filter out the birds that are detected out of line of site. I posted some time ago on that and still have no solution (WIP). When the unit is powered on but no satellites detected, output sentences in order of reception are GGA, GSA, GSV, RMC no PPS output When satellites are visible but no fix is available GGA, GSA, GSV, GSV, RMCnumber of GSV may vary due to those in view, but I always got 2 in this state no PPS output When a fix is available GGA, GSA, GSV, , GSV, RMC PPS is output Although the manual indicates that GLL and VTG are supported, I did not see either of these messages. I haven't tried manually configuring the chip. I do not know whether it goes to position hold, but suspect not. I scoped the PPS/NMEA stream output. PPS and. NMEA signal taken from test pads on the edge of the board. NMEA stream start is always at 300ms from the PPS . I guess that the end is variable depending on the number of birds in view, but for me, the stream ended at +720ms all through my test. So at least on this unit the data does not leak into the following second. That delay can be configured out in NTP. I selected just the GGA sentences for my test with the generic NMEA driver and it works ok. Though as I have better sources available I wouldn't use it to serve time. PPS measurement - the PPS is positive going and 100ms long . The doc I have been able to get at says that it is 200ms long. Anyway, what we get is exploitable without pulse stretching over the serial interface, once it is hooked up. The signal at the test pad is not a very good square wave with respect to the motorola receivers. It has a rise time of nearly 100ns and does not settle to 3v (not 3.3) until 500ns or more. There is no jitter that I can see (5ns ?), but would I see any?. Still for my purpose , NTP , it was a possible candidate. The PPS is not available on the DB9 connector. It is however a pretty simple operation to get it as there are unused pins on the SP232ECN driver chip. I connected the test pad to pin 11 and pin 14 out to the DB9 pin 1 leg for a DCD input to the PC rs232 port. The RS232 transition is +/- 5V in 750ns. However, although the PPS looks nice and steady on the scope , for some reason I did not get offsets from UTC measured by NTP using the ATOM driver that were as good as those from the motorola boards . I haven't investigated why, as the major issue for me is that the board is too big to fit in a Soekris case and can only be powered (standard hook up) by the USB interface, and although the Soekris has a USB interface, the size problem makes it a nono. I will probably hot glue it to a PC. I can then use both the NMEA and PPS together quite reasonably. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Sure Electronics GPS
Rix Seacord wrote: The SureElectronics unit is general within 10 feet with no observed off the wall excursions. One possibility Rix, perhaps it may be like the Garmin 18x which has a very stable position with no sudden excursions ( with its Average Mode ON ). The 18x gives position in discrete 13 cm steps (quanta) of longitude, that change very slowly (if the GPS is stationary). However when the 18x is averaged long term, it has the same ability to predict position as a standard GPS receiver whose output is averaged long term. So maybe, what you are seeing, is a heavy filtering algorithm in action. Regards, Geoff. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Sure Electronics GPS
The DC468 simulator is not at all picky accept for the one time sentence. I think I looked at the same unit but was thinking about the jitter and accuracy of the 1 pps for a gps controlled oscillator. It was not really apparent, but I think it was not a good choice for that app. Regards Paul. On Sun, Jan 16, 2011 at 11:40 PM, jim s j...@jwsss.com wrote: I was looking at one of these units for the conversion project for the 468 clocks, sounds like these might be good units. I think I searched for gps and rs232 and hit them on the first page. JIm On 1/16/2011 5:07 PM, Tom Clifton wrote: I have purchased many items over the past few years from Sure and have never been dissapointed in that I receive. They do seem to have multiple seller accounts, each with different items - sureelectonics sureelectronics1 sureelectronics2 etc. Any way, I did a serch by seller and found a MG1613S Bluetooth/RS232 /USB UART GPS Module Demo Board item # 350239551536 by seller sureelectronics1 Don't know if this is the exact unit being discussed, but it may be a start. As usual, shipping is from China - delivery will take perhaps 2 weeks but If you aren't in a hurry you will probably be happy with what you receive. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Sure Electronics GPS
Has anyone had any experience with the demo gps receiver being sold on Ebay by Sure Electronics. I have been running one, off and on, for about a month. The stability of its position plots is unbelievable compared to similar plots from Motorola Oncore, Garmin and Trimble Thunderbolt receivers. It is very nice, for the price. Detailed lab report here: http://www.leapsecond.com/pages/MG1613S/ /tvb ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Sure Electronics GPS
This particular link does not seem to offer the gps board On Mon, Jan 17, 2011 at 10:02 AM, Scott Burris slbur...@gmail.com wrote: On 1/16/2011 9:49 PM, Rix Seacord wrote: Dick and Tom The gps is sold on ebay in several different versions. The don't have a web site under their name. The manual, virtual drivers and software are down loadable via their ebay offer. There is a www.sure-electronics.com site but it takes you to ebay. Their web site is http://www.sureelectronics.net/ I used to buy from them on ebay, but mostly just direct now. I've never had a problem with them. Scott ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Sure Electronics GPS
http://www.sureelectronics.net/goods.php?id=99 Scott On 1/17/2011 8:27 AM, paul swed wrote: This particular link does not seem to offer the gps board On Mon, Jan 17, 2011 at 10:02 AM, Scott Burrisslbur...@gmail.com wrote: On 1/16/2011 9:49 PM, Rix Seacord wrote: Dick and Tom The gps is sold on ebay in several different versions. The don't have a web site under their name. The manual, virtual drivers and software are down loadable via their ebay offer. There is a www.sure-electronics.com site but it takes you to ebay. Their web site is http://www.sureelectronics.net/ I used to buy from them on ebay, but mostly just direct now. I've never had a problem with them. Scott ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Sure Electronics GPS
Got a link ? A search on Sure Electronics comes up empty. 73, Dick, W1KSZ -Original Message- From: Rix Seacord eseac...@verizon.net Sent: Jan 16, 2011 3:35 PM To: time-nuts@febo.com Subject: [time-nuts] Sure Electronics GPS Has anyone had any experience with the demo gps receiver being sold on Ebay by Sure Electronics. I have been running one, off and on, for about a month. The stability of its position plots is unbelievable compared to similar plots from Motorola Oncore, Garmin and Trimble Thunderbolt receivers. -- Rix Seacord K2AVP eseac...@verizon.net 845-628-0892 914-262-9186 ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Sure Electronics GPS
I have purchased many items over the past few years from Sure and have never been dissapointed in that I receive. They do seem to have multiple seller accounts, each with different items - sureelectonics sureelectronics1 sureelectronics2 etc. Any way, I did a serch by seller and found a MG1613S Bluetooth/RS232 /USB UART GPS Module Demo Board item # 350239551536 by seller sureelectronics1 Don't know if this is the exact unit being discussed, but it may be a start. As usual, shipping is from China - delivery will take perhaps 2 weeks but If you aren't in a hurry you will probably be happy with what you receive. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Sure Electronics GPS
I was looking at one of these units for the conversion project for the 468 clocks, sounds like these might be good units. I think I searched for gps and rs232 and hit them on the first page. JIm On 1/16/2011 5:07 PM, Tom Clifton wrote: I have purchased many items over the past few years from Sure and have never been dissapointed in that I receive. They do seem to have multiple seller accounts, each with different items - sureelectonics sureelectronics1 sureelectronics2 etc. Any way, I did a serch by seller and found a MG1613S Bluetooth/RS232 /USB UART GPS Module Demo Board item # 350239551536 by seller sureelectronics1 Don't know if this is the exact unit being discussed, but it may be a start. As usual, shipping is from China - delivery will take perhaps 2 weeks but If you aren't in a hurry you will probably be happy with what you receive. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Sure Electronics GPS
Dick and Tom The gps is sold on ebay in several different versions. The don't have a web site under their name. The manual, virtual drivers and software are down loadable via their ebay offer. There is a www.sure-electronics.com site but it takes you to ebay. The one I have uses a skylab receiver but it appears later versions use a different receiver. With either one of the 2 gps antennas I have up, the Thunderbolt accuracy runs plus or minus 30 feet and sometimes greater. Occasional position excursions up to several hundred feet sometimes occur. The SureElectronics unit is general within 10 feet with no observed off the wall excursions. With that in mind, I wonder how accurate is their 1pps output? Once I get my gpsdo project out of the way, I plan on learning how to test it more thoroughly. Having just returned to ham radio after a 40+ year absence I have a lot to catch up on. Rix Seacord K2AVP eseac...@verizon.net 845-628-0892 914-262-9186 On 1/16/2011 6:02 PM, Richard W. Solomon wrote: Got a link ? A search on Sure Electronics comes up empty. 73, Dick, W1KSZ -Original Message- From: Rix Seacordeseac...@verizon.net Sent: Jan 16, 2011 3:35 PM To: time-nuts@febo.com Subject: [time-nuts] Sure Electronics GPS Has anyone had any experience with the demo gps receiver being sold on Ebay by Sure Electronics. I have been running one, off and on, for about a month. The stability of its position plots is unbelievable compared to similar plots from Motorola Oncore, Garmin and Trimble Thunderbolt receivers. -- Rix Seacord K2AVP eseac...@verizon.net 845-628-0892 914-262-9186 ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Sure Electronics GPS
I found those too. But also found many Motorola units that had what I thought were better specs, and certainly better written user manuals. I guess you could run the suplied software and then snoop on the serial interface to figure out what commands the sure GPS accepts. Can it be put into position hold mode for timing? Can it do self survey? I paid $20 for am Oncore GPS that I think works better for timing then this. On Sun, Jan 16, 2011 at 8:40 PM, jim s j...@jwsss.com wrote: I was looking at one of these units for the conversion project for the 468 clocks, sounds like these might be good units. I think I searched for gps and rs232 and hit them on the first page. JIm On 1/16/2011 5:07 PM, Tom Clifton wrote: I have purchased many items over the past few years from Sure and have never been dissapointed in that I receive. They do seem to have multiple seller accounts, each with different items - sureelectonics sureelectronics1 sureelectronics2 etc. Any way, I did a serch by seller and found a MG1613S Bluetooth/RS232 /USB UART GPS Module Demo Board item # 350239551536 by seller sureelectronics1 Don't know if this is the exact unit being discussed, but it may be a start. As usual, shipping is from China - delivery will take perhaps 2 weeks but If you aren't in a hurry you will probably be happy with what you receive. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. -- = Chris Albertson Redondo Beach, California ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Sure Electronics GPS
With that in mind, I wonder how accurate is their 1pps output? Pretty good for $40. About 60 ns peak-to-peak (22 ns stdev) about the mean. /tvb ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
