Close

Ditch the discrete RTC

A project log for Sunrise MkII

Basic sunrise simulator / light based alarm clock - in a jar

david-brownDavid Brown 11/17/2016 at 23:010 Comments

Given that the having a high accuracy clock is not strictly required for this application, and that i've been having issues with the clock corrupting from the voltage spike of switching on/off i've decided to remove the RTC and associated components and move the crystal over to the ATMega to have that run the time keeping itself.

I found an atmel application note for RTC using the asynchronous timers [Ref. http://www.atmel.com/images/Atmel-1259-Real-Time-Clock-RTC-Using-the-Asynchronous-Timer_AP-Note_AVR134.pdf]

This also brings the total cost down for the control components by about a third.

Discussions