The Timecode Shield prototype gets an RTC clock today using the DS3231.
this chip has an Accuracy ±3.5ppm from -40°C to +85°C which is'nt too bad. ( its cheap ! )
next will be 2.4ghz for syncing to other shields or an oled screen, not sure in which order.
still battling with LIBLTC and the codec library. I think I will have to try and hack the codec lib to include the 8bit copy to LIBLTC since I have no idea how to add this in the Timer1 section of the code. I'm also thinking perhpas there just is'nt enough horse power on the arduino uno to process the 16bit audio from the codec into 8bit and get LibLTC decoding the LTC.
I might try this shield on arduino Due. I would like to get this running on the UNO if possible though !!
anyway , heres a pic of the rough prototype with the RTC chip / battery wired up and working.