Making a radio signal

Hello everyone, I just recently started using my gps/pps setup for chrony (@Bas not using google anymore :slight_smile: ). I wonder if it is possible to make a little beep (like wwv or the others) every second? I am using a rasberry pi 4 which is capable of transmitting. Would I need to directly use /dev/pps0?


What type of radio signal do you want to use?
As you are not allowed to transmit freely without approved equipment.

As for PPS0, I do not use it with my USB-PPS-GPS, I use this on /etc/default/gpsd:

# Default settings for the gpsd init script and the hotplug wrapper.

# Start the gpsd daemon automatically at boot time

# Use USB hotplugging to add new USB devices automatically to the daemon

# Devices gpsd should collect to at boot time.
# They need to be read/writeable, either by user gpsd or the group dialout.

# Other options you want to pass to gpsd

And in chrony.conf, this for GPS usage:

refclock SHM 0 refid GPS poll 3 precision 1e-3 offset 0.127
refclock SHM 1 refid PPS poll 2 precision 1e-9 lock GPS prefer

As for the beep, why not simply use a 1-sec crontab to make the beep? Your systemclock should be spot on, so crontab would be too (or very close).

Transmitting with a RPi is not advised as it doesn’t contain harmonic-filtering and you could end up in big trouble if you disturb importent systems near you.
Best not try that without knowledge of transmitters.

Bas - ON5BAS.

I remembered something like Project: μWWVB · cat /var/log/build a while back. It’s not what you want.