GPS clock

There are two separate yet related goals here:

• Create a local timeserver for my network, based on a GPS time-source on a raspberry-pi.
  • Should use a 1PPS capable GPS module.
  • Doesn't really need a display, though it can have one.
  • Wired networking is fine
  • I think it can almost entirely be based on existing packages, like gpsd, ntpd, etc.
• Create a standalone clock, using a GPS source, based on a raspberry-pi
  • GPS can be a simple cheap, available one.
  • Doesn't really need super-accurate inter-second timing, we're only going to display

  to the nearest second anyway.

• • Absolutely needs a display of some sort
  • Should be able to work with no network at all. If wireless is available, to do FW updates or something, bonus.
  • Power usage is somewhat of a concern, though could start out using wall-wart power
  • A big 5" or 7" touch display is way overkill, but could display sun location, etc, and use touch for setup
  • Use GPS co-ords to pick local timezone.
  • OLED screen and batteries?
  • Could we get away with solar power?
  • low-power mode is a goal to get us off the plug
  • any way we can have it turn the display off when its not light out? or when I'm not looking at it? :)

Things to Display

• Date & Time in several formats:
  • UT1
  • UTC
  • Unix
  • Local
  • MST
  • AST
• Number of satellites used in fix
• Battery power left
• Day of week (text) and month of year (text) and week of year (numeric, ISO)
• Time to sunset/since sunrise
• Temp/humidity/pressure
• latitude/longitude
• local time-zone
• DST active

Things to Adjust

• Ideally nothing, other than date/time display preferences:
  • 12-hour/24-hour?
  • ISO formatting options?
  • which time choices (above) to display at all times
• Other localization settings & options
  • C/F for temp
  • Power-saving settings?
• Some way to initiate FW updates?
  • Would be cool if it would detect when my phone is making Wifi available, then:
    • connect to that
    • check git for FW updates (or somewhere)
    • check somewhere for OS and kernel updates
    • update itself if needed
    • reboot/restart app if needed

Anything else to make available?

• Maybe a calculator? phone or laptop is more convenient, probably
• Some sort of calendar mode? Again, for something like this, more than a glance, phone/laptop more convenient
• Something else I could see at a glance? Home status?