Re: [gpsd-users] Problem with gpsd blocking device while it doesn't send NMEA messages

[Larry Boyd]

You are misunderstanding those "older descriptions". In every case (both links that I shared with you), the connection is NOT closed. In other words, you need to keep picocom (or whatever other software you are using, like wvdial or chat or anything else) RUNNING. Once the file descriptor used to send the start instruction is closed, IT WILL SHUT OFF.

When I suggested to you to look into sending the start instructions as a CONTROL STRING, the idea is that you will use gpsd's file descriptor to send the start instruction, thus eliminating the need to have some other program running in order to keep it on.

On Fri, Jul 7, 2017 at 11:00 AM, Thomas Engerer <address@hidden> wrote:

>> If i now open a second terminal and point cat to the device, I also
>> get the NMEA data (as described in descriptions). But as soon as I
>> close picocom, no more data appears. 
>
> Not a gpsd problem if it happens before you use gpsd.
> 
> Also, I do not see how you can 'cat' from a device that is already opened
> by your picocom.  The kernel should prevent that.

I found some older descriptions stating that you should be able so see the NMEA data via cat after the 'initialisation'.

But for me this only works during the connection (in my case with picocom) is still open.

 

> One big important detail: what GPS are you using?  Got a pointer to its
> documentation?
> 
> Which gpsd are you using?  Did you build it yourself?  Does it hae the
> GPS driver you need?

Im using the 'Lenovo' (Ericson) F5521GW WWAN modem with included GPS reciever.

The drivers came with the installation of ubuntu 16.04, i didn't install any manually.

I would guess the driver is ok (it ouputs the data in certain constellations).

 

> To eliminate some variables, what happens if you try just:
>         gpsmon /dev/ttyAMA2

 

If I don't have picocom running with the AT-commands send, I don't get any output (no NMEA data).

 

Best regards

ET