An Ultra High Precision Alarm Clock with ten year battery backup.

  • TCXO Clock Oscillator, +/-2ppm 0-40C
  • Month-Day-Year Calender
  • Day of Week Selectable Alarm
  • Large Minutes:Seconds Display
  • Temperature and Relative Humidity Display, DHT22 sensor
  • Intuitive User Keypad
  • Snooze Function
  • Multi Function 'Snooze' & 'Cancel' Buttons allow for Backlight Operation: 'Momentary' and 'On/Off'

  • I really need to date these postings.

    This clock was built using the very common DS1307 RTC and coupled to the highly accurate DS32KHz TCXO. Something like I had implemented back in 2002 . This clock was put together in 2013 and has performed flawlessly once the watchdog was implemented. Now AdaFruit has made available a DS3231 module that combineds the RTC and TCXO. Using spare parts, I assembled a second clock only using an Ebay DS1307 module. The clock gained about a minute a week so I replaced the DS1307 with the new DS3231 module. Some minor code changes were needed, mostly to handle day light saving time changes due to the loss of the RTC's NVRAM. The alarm functions added to the DS3231 seemed pretty useless as they did not implement multiple days of the week, one of the main features of the uberCLOCK.

    Somewhere along the way, I made a case from re-purposed resawn mahogany and finger joints.