guzon:
I seem to be having some trouble with your sketch TimeInternalRTC_interrupts. I have added TimeLIb.h to my libraries but I still get undefined reference errors to any call to the lib while compiling the sketch.For this project I'm not interested in a fully capable clock, I just want something to interrupt the normal loop and run a quick calculation every few seconds.
Could you see me the compiled debug please?
Have you replaced fully the directory of the old TimeLib by this new fork? Time.cpp and others files are important also.
This lib is fully capable to generate an interrupt in your sketch every time by second (by power of two: 1x, 2x, 4x, 8x... to 8192x by sec).