On 2012-10-28, David Taylor <[email protected]> wrote: > On 28/10/2012 08:28, Rob wrote: >> David Taylor <[email protected]> wrote: >>> First problem with gpsd resolved, I needed a "-n" on the command-line! >>> >>> Next step is to see how the time a GPIO pin is triggered can be written >>> into the SHM memory block, or whatever.... >> >> gpsd writes the time into the SHM block. >> you need a serial port with data and DCD, and connect the pulse per >> second output of the trimble to the DCD. >> when that works you will have two SHM blocks, one with the time from >> the serial messages and another with the time from the PPS. > > Thanks, Rob, Herein lies a problem in that the Raspberry Pi doesn't > have a serial port, let alone one with a DCD line, so you need to use > one of the available I/O pins to raise the interrupt. I gather that the > kernel supports this, but I'm then unsure how to get NTP to read the > time from gpsd, and the PPS from another source. There is some work > described here: > > https://github.com/davidk/adafruit-raspberrypi-linux-pps > > but I'm unsure how to make that work with my later version of Linux.
GEt pps-gpio (eg http://lxr.free-electrons.com/source/drivers/pps/clients/pps-gpio.c) and compile it as a module for your current kernel. Or put it into dkms so it will be automaticaly compiled for any new kernel you install. _______________________________________________ questions mailing list [email protected] http://lists.ntp.org/listinfo/questions
