/diy/ - Do It Yourself

>>1569701
internal RCs are rarely specified to better than 2% over process/voltage/temperature after calibration
if you care about real time, use watch crystals

>>1569703
>power
well, the display alone is eating (typically) 1.2mA plus whatever for the bias generator plus whatever for the signalling between the display and the MCU, all this ignoring the backlight. it's almost certain that the MCU will be consuming somewhat less than that
it's one of those things where you have to look in the datasheet of the particular MCU you choose and do a bit fo reckoning. in Atmel's datasheets, graphs like Pic related can be found in the "Typical Characteristics" section