Oscilloquartz STAR 4 GPSDO - RS232 output (lack of)? - Page 1
Forum section: electronics / testgear

author: jpb
author_rank: Super Contributor
timestamp: May 11, 2018, 07:41:34 pm
content: Following advice on this forum I bought one of the Oscilloquartz Star4 based GPSDOs fro amoj1010:https://www.ebay.co.uk/itm/10Mhz-GPSDO-OSCILLOQUARTZ-OSA-OEM-GPS-GPSDO-10MHz-1PPS-STAR-GPS-Clock/262861459973?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2060353.m2749.l2649It seems to work well even with the provided antenna, I have tested it against a recently acquired standard based on the 198kHz radio signal.But I can't get anything out of the RS232 output. I have tried two usb to rs232 converters, most recently a very expensive industrial one.Looking on my scope pin 8 shows the 1pps nicely, pin 2 (Tx) sits at -5.8V and pin 3 (Rx) sits at 0V (approximately).Is there something I need to do to wake it up? I've tried connecting with Lady Heather, with Putty with a GPS display program and with PowerShell and get no response out of any of them.Is it broken or am I doing something silly - I suspect the latter.With other RS232 things I've found that you can send a *IDN? and get something out.I've assumed the normal default baud rate of 9600.Help

author: texaspyro
author_rank: Super Contributor
timestamp: May 12, 2018, 03:42:55 am
content: These things have their own command language. They do not output anything unless commanded. What version of Lady Heather are you using? Did you specify the /rx4 command line option?

author: jpb
author_rank: Super Contributor
timestamp: May 12, 2018, 10:55:22 am
content: Quote from: texaspyro on May 12, 2018, 03:42:55 amThank you for replying.I'm using version 5.0 (I've just downloaded it so assumed it was the most recent.) I've not tried /rx4 - I will give it a go.Thank you very much - /rx4 did the trick (/5 to set COM5 and then /rx4). I thought it must be something simple I wasn't doing but my scan of the options didn't yield anything.

author: BravoV
author_rank: Super Contributor
timestamp: May 12, 2018, 10:57:16 am
content: Get v6 here ->https://www.eevblog.com/forum/metrology/lady-heather-v6-beta-for-windows-exe/

author: jpb
author_rank: Super Contributor
timestamp: May 12, 2018, 11:09:01 am
content: Quote from: BravoV on May 12, 2018, 10:57:16 amThankyou - I'll do that, though v5 is now working since I entered the correct /rx4 command. It is good to see the Tx and Rx lights flashing on and off on my RS232 after two evenings of nothing!

author: BravoV
author_rank: Super Contributor
timestamp: May 12, 2018, 11:12:19 am
content: Quote from: jpb on May 12, 2018, 11:09:01 amCongratz, and it will be much more exciting, once the "locked" sign pops up.

author: Dwaine
author_rank: Frequent Contributor
timestamp: May 12, 2018, 01:53:40 pm
content: I have the same device. Works great. I did the management modification and tapped the 10mhz square wave.

author: Mrt12
author_rank: Regular Contributor
timestamp: March 18, 2019, 12:25:02 pm
content: Quote from: Dwaine on May 12, 2018, 01:53:40 pmwhat kind of management modification is this?

author: texaspyro
author_rank: Super Contributor
timestamp: March 18, 2019, 07:13:19 pm
content: Quote from: Mrt12 on March 18, 2019, 12:25:02 pmThe original packaged up version of this GPSDO brought the GPS receiver data out the RS-232 port. Later version brought out the "management" interface that lets you monitor more stuff and configure some settings. The modification swaps the RS-232 port from the GPS data to the management interface. Lady Heather works with the management interface.

author: Ohm_My
author_rank: Contributor
timestamp: June 04, 2019, 07:59:29 am
content: Is their any way to get the RS232 enabled on the LEA-5T chip? So much more could be done with this GPSDO if the ublox u-center application could see it.

author: texaspyro
author_rank: Super Contributor
timestamp: June 04, 2019, 05:41:07 pm
content: Quote from: Ohm_My on June 04, 2019, 07:59:29 amI seriously doubt that... like what could u-center bring to the party?

author: Ohm_My
author_rank: Contributor
timestamp: June 18, 2019, 01:54:36 am
content: Quote from: texaspyro on June 04, 2019, 05:41:07 pmWell for starters I could put the module in a fixed timing mode with a precise known location. I'm seeing a difference of location in the 24 hour survey that is run on unit startup versus several PPP observations that I have done that result in <.013 meter accuracy.