LDC paired with Arduino locks up and freezes. Out of SPRAM?
I found the problem! it was specific to my code and didn't turn out to have anything to do with ram or power. The problem was I hadn't detached the interrupt from the rtc when I woke it up with a button. It would freeze seemingly randomly because the rtc would fire an interrupt signal when the next minute ticked, while the arduino was awake. I guess it causes problems when you try to interrupt arduino's sleep and it's not actually sleeping. All I had to do was detach both interrupts when the button is clicked. Thank you all for your help :)