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

[hans mayer]

> 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

no GPIO pin 18 is not a serial pin. it is a pin for the 1PPS signal.

download and compile gpio. than you can see it.

# gpio readall
 +-----+-----+---------+------+---+-Model 
B2-+---+------+---------+-----+-----+
 | BCM | wPi |   Name  | Mode | V | Physical | V | Mode | Name    | wPi 
| BCM |

+-----+-----+---------+------+---+----++----+---+------+---------+-----+-----+
 |     |     |    3.3v |      |   |  1 || 2  |   |      | 5v      | 
 |     |
 |   2 |   8 |   SDA.1 |   IN | 1 |  3 || 4  |   |      | 5V      | 
 |     |
 |   3 |   9 |   SCL.1 |   IN | 1 |  5 || 6  |   |      | 0v      | 
 |     |
 |   4 |   7 | GPIO. 7 |   IN | 1 |  7 || 8  | 1 | ALT0 | TxD     | 15 
 | 14  |
 |     |     |      0v |      |   |  9 || 10 | 1 | ALT0 | RxD     | 16 
 | 15  |
 |  17 |   0 | GPIO. 0 |   IN | 0 | 11 || 12 | 0 | IN   | GPIO. 1 | 1 
 | 18  |
 |  27 |   2 | GPIO. 2 |   IN | 0 | 13 || 14 |   |      | 0v      | 
 |     |
 |  22 |   3 | GPIO. 3 |   IN | 0 | 15 || 16 | 0 | IN   | GPIO. 4 | 4 
 | 23  |
 |     |     |    3.3v |      |   | 17 || 18 | 0 | IN   | GPIO. 5 | 5 
 | 24  |
 |  10 |  12 |    MOSI |   IN | 0 | 19 || 20 |   |      | 0v      | 
 |     |
 |   9 |  13 |    MISO |   IN | 0 | 21 || 22 | 0 | IN   | GPIO. 6 | 6 
 | 25  |
 |  11 |  14 |    SCLK |   IN | 0 | 23 || 24 | 1 | IN   | CE0     | 10 
 | 8   |
 |     |     |      0v |      |   | 25 || 26 | 1 | IN   | CE1     | 11 
 | 7   |

+-----+-----+---------+------+---+----++----+---+------+---------+-----+-----+
 |  28 |  17 | GPIO.17 |   IN | 0 | 51 || 52 | 0 | IN   | GPIO.18 | 18 
 | 29  |
 |  30 |  19 | GPIO.19 |   IN | 0 | 53 || 54 | 0 | IN   | GPIO.20 | 20 
 | 31  |

+-----+-----+---------+------+---+----++----+---+------+---------+-----+-----+
 | BCM | wPi |   Name  | Mode | V | Physical | V | Mode | Name    | wPi 
| BCM |
 +-----+-----+---------+------+---+-Model 
B2-+---+------+---------+-----+-----+

see also

http://www.elektronik-kompendium.de/sites/raspberry-pi/1907101.htm

gpio pin 18 is physical pin 12 ( don't ask me why )
it's the BCM pin 18 mentioned with gpio pin 18 and not GPIO.18
total confusing. but
it is so, believe me.

kind regards
hans

--


Am 03.03.2016 22:20, schrieb 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.