[LinuxPPS] do we need hardpps <- yes!!

[Hal V. Engel]

On Saturday 06 February 2010 06:28:26 am Udo van den Heuvel wrote:
> On 2010-02-06 15:08, Remco dB wrote:
> >> I was thinking of using the falling edge trick for serial GPS as well.
> >> But this doesn't look so feasible now with this GPS.
> >
> > For more precision concerning the second epochs, a Motorola
> > Oncore GPS-receiver could be used.
> > At this time of writing a Chinese supplier sells UT+'s for U$ 5.00 (!)
> > excl posting and shipping on Ebay.
> 
> Interesting!
> I have my Motorola's here.
> I still haven't come to implement them. (would need to put the antenna
> on the edge of the roof)
> 
> Also: would running 2 GPS receivers on one irq be bad?
> Does LinuxPPS deal with that at all?

Timing units like the OnCore UT+ have the ability to be configured to have the 
timing pulse precisely offset from the actual seconds epoch.  This is 
specifically to allow for several things including having the pulses from 
several devices occur at different times to prevent them from causing 
contention issues. 

> 
> Hmm:
> # cat /proc/interrupts
>            CPU0
>   0:         49   IO-APIC-edge      timer
>   1:       1892   IO-APIC-edge      i8042
>   3:   91401282   IO-APIC-edge      serial
>   7:          0   IO-APIC-edge      parport0
>   9:          0   IO-APIC-fasteoi   acpi
>  14:          0   IO-APIC-edge      ide0
>  15:   14706315   IO-APIC-edge      ide1
>  17:      60933   IO-APIC-fasteoi   HiSax, HDA Intel
>  18: 1521039453   IO-APIC-fasteoi   eth1
>  19:  977446806   IO-APIC-fasteoi   eth0
>  20:          0   IO-APIC-fasteoi   uhci_hcd:usb2
>  21:          0   IO-APIC-fasteoi   uhci_hcd:usb4
>  22:          0   IO-APIC-fasteoi   uhci_hcd:usb3
>  23:          0   IO-APIC-fasteoi   ehci_hcd:usb1
> NMI:          0   Non-maskable interrupts
> LOC:  953308699   Local timer interrupts
> SPU:          0   Spurious interrupts
> ERR:          0
> MIS:          0
> 
> Strangely I do not see my gps (ttyS0, irq4?) but I do see interrupt 3
>  (ups). Why?
> 
> _______________________________________________
> LinuxPPS mailing list
> LinuxPPS at ml.enneenne.com
> http://ml.enneenne.com/cgi-bin/mailman/listinfo/linuxpps
> Wiki: http://wiki.enneenne.com/index.php/LinuxPPS_support
>