Re: [gpsd-users] Is GPSD receiving PPS?

[Jon Brase]

Hans,

Ok, so my understanding at this point is that GPSD needs the PPS signal to go to the GPIO pin that the Pi uses for serial carrier detect, I can't just have the kernel use an arbitrary pin? I'd used a hardware setup walkthrough that recommended assigning GPIO pin 18 on the Pi on the basis of adjacency to the serial pins,  but I'm not sure it itself is a serial pin. Anyways,  shouldn't be too much trouble to change, just moving a jumper and editing my boot parameters.

Jon Brase

-------- Original message --------
From: MAYER Hans <address@hidden> 
Date:03/03/2016  09:19  (GMT-06:00) 
To: address@hidden 
Cc:  
Subject: Re: [gpsd-users] Is GPSD receiving PPS? 


Hi Jon,

I think, this are 2 different pair of shoes.
The 1PPS you see with the "ppstest" command is a high/low signal on one of the pins of the GPIO module.
"gpsd" needs a serial interface on which data are received.
With which interface did you start "gpsd" ? Is this the line where Adafruit is sending information ? 
Can you read the data for example with "minicom" or another terminal program ? 
Did you disable this interface within the operating system to prevent that "getty" is starting on it ? 

Kind regards 
Hans



-----Original Message-----
From: address@hidden [mailto:address@hidden On Behalf Of Jon Brase
Sent: Thursday, March 3, 2016 8:33 AM
To: address@hidden
Subject: [gpsd-users] Is GPSD receiving PPS?

Greetings,

I'm running GPSD on a Raspberry Pi with an Adafruit GPS hat. I know that the hardware supports PPS and that I've got the wiring and kernel configuration right because I i get timestamped assert messages with sequence numbers when I run "ppstest /dev/pps0". However, I am not certain that GPSD is actually receiving PPS data. Gpsmon does not indicate that I am getting any PPS data. When I run GPSD itself at debugging level 5 I do not get the carrier detect lines that http://www.catb.org/gpsd/gpsd-time-service-howto.html suggests I should be seeing. If I run CGPS, GPSD starts printing a bunch of lines similar to the following in its output:

gpsd:PROG: Changed mask:  
{ONLINE|TIME|LATLON|SPEED|TRACK|PACKET|REPORT|PPSTIME} with reliable cycle detection

I'm not sure if the "PPSTIME" bit indicates that I'm getting PPS or not.  
Is GPSD receiving PPS? If not, what could cause it not to receive PPS when the kernel is receiving PPS? "gpsd -l" indicates that GPSD is compiled with PPS support, and GPSD is being launched as root at boot.

Jon Brase

PS: A previous copy of this message got mangled by my mail client and sent out without a message body. My apologies for any confusion this may have caused.