GPS connection not established

I am trying to work with the Raspberry shake seismometer at my university in Israel via GPS (without an internet connection). Still, from my logs (attached), it seems that the GPS is unable to synchronize with my local time and thus is not working. Though it may be related to firewall issues, I also do not have a server connection, and I contacted our IT for further assistance. So my question is, may the connection of the GPS be related to firewall issues either?

I would be glad if you could look into my log files and provide me with a solution, mainly if the problem with the GPS derives from an alternative reason or any other issues you may notice.

Thanks and Regards

RSH.RC0B4.2021-11-09T08_53_45.logs.tar (2.1 MB)

Hello Michatse, welcome to our community!

Thank you for contacting us about this issue and for providing the logs from the Shake. It seems, indeed, that the unit is not acquiring signal from the GPS. To answer your question, no, any firewall issue does not involve the GPS timing services since they are two separate ones, and your instrument is not connected to any local network from what you are writing.

Could you please SSH into the Shake (instructions here: ) and execute this from the command line?

ntpq -p

You can post a screenshot (or a copy-paste of the result in your answer.

After this, could you shut down the Shake, turn it on again, wait for around half an hour, download the new logs and post them again?

Also, could you then re-execute ntpq -p and attach the new result too? I want to check if there are any apparent differences between the Shake running from some time, and a freshly started system.

Thank you for your collaboration.

Hi Stormchaser. Thanks for the prompt response; my Shake device is connected to the university’s local network (otherwise, it is not working. I believe when the GPS issue is fixed, it won’t be necessary anymore).
I executed the command you asked and got this:
after rebooting and waiting half an hour, I got the same message again (I also tried sntp to the localhost, but it seems there is no response; however, the pinging to the localhost works fine):

the new logs (a hour after rebooting) are attached (It takes a lot of time to download them again, maybe firewall issues so I had to wait longer):
RSH.RC0B4.2021-11-14T09_13_22.logs.tar (2.2 MB)

However I have noticed that after a day or so the GPS starts working (as it seems)
RSH.RC0B4.2021-11-14T08_46_14.logs.tar (2.2 MB)
But as you understand it is not an optimal solution to wait that amount of time every time I want to use a GPS.

Thank you

Hi Stormchaser. It seems that the GPS is working now:
However, after disconnecting the Internet cable from the device I was unable to access it
by ssh. Is it should be that way? cause now I am unable to access it through http://rs.local/ either.


It’s very common to experience a long delay when using a GPS receiver for the first time. It’s because firstly the receiver must find at least 3 satellites in view at the same time, and from each download an ephemeris table. This table tells the receiver where and when it plans to be in the next little while. The first time it’s a full version and sizable amount of data. Subsequently it’s just an update and much quicker.
If the GOS receiver is powered down for a lengthy time and/or the receiver is moved, then it can happen that the ephermeris needs to be reloaded.

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