[LinuxPPS] Kernel configuration and more ......

[Rodolfo Giometti]

On Tue, Oct 30, 2007 at 11:18:54AM +0000, Paul wrote:
> Even more for you.
> I rebooted and used ppsctl to enable /dev/ttyS0
> The assert flag was at zero and zero serial and did not change.
> Now, to check if the port I had the plug in was correct I used minicom
> to look at the NMEA data.
> After shutting down minicom I checked the assert again which had changed
> to show a sensible timestamp and a serial of 69, but still it did not
> change.
> So it seems as though the events are being registered while minicom is
> running, but not otherwise.

These sound reasonable since the serial port is "enabled" only when an
userland process opens it. Since your PPS source is connected with the
serial line you cannot get PPS events till the serial port is not
enabled/opened. Some GPS antenna also needs a special init sequence
commands over serial line before starting PPS signal.

Ciao,

Rodolfo

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