Quote
bobc
We don't need 12 bit resolution on thermistors though. We can also afford to have a lot of filtering on the inputs, because temperature varies relatively slowly.
Well, we do and we don't. If you want to set up to print at 150C one day and 300C the next day having a couple more bits would be quite handy with the standard choices of 1K or 4.7K ohms. The temperature resolution gets pretty poor at the high end with a 4.7K resistor. Indeed a lower resistor would help this quite a bit. A much lower value would make the resolution around room temp a bit poor. You might start getting mintemp errors as a result. Having reasonable resolution at room is also a good reality check when first setting up the printer.
With all metal hot ends coming along and some of the more exotic filaments, 300C printing is indeed a very real possibility. Tables probably should go to 350C for safety's sake if you are running that hot. Who knows how happy the thermistors will really be up there.....