I did kill a couple of Arduino chips trying to run the unit of 12 volts, though. In the end i used a breakout board with its own regulators
Yeah, dunno how, but magic smoke events didn't come to mind immediately for me with this thread... they're certainly prone to it.
I'd recommend never using the onboard regulator unless you're only powering the chip itself and maybe some very minimal requirements needed for sensors. This seems to be particularly true when it comes to "shield" displays and the backlights. Would appear that the LEDs just pull things way too close to the regulator limits depending on what you've got. Not worth the risk. I use "full spec" 7805 or some other form of external supply now for anything like that, haven't had any trouble since.
Just in playing around with Miles Burton's DS18B20 library with multiple sensors, I find I get occasional bad reads. Figure they will figure it out some day.
The good news is, there are relatively simple workarounds for this provided the bus itself isn't experiencing severe interference. There are ways to read the bus blazing fast, and between CRC and a couple other tricks, can eliminate the bad reads.
I'll never use NTC/ADC for temp ever again whenever I can avoid it.
That said, I agree it's definitely got its uses (fan or PWM control, etc) but only when the outcome isn't in need of a calibrated number. Too much work hehe