I hate to bring this up, given past articles, but here goes: Upgraded to Marlin 2.1.2.1 (may or may not be significant), also installed magnetic surface with magnetic rubber backing on glass plate, which MAYbe a factor due to higher thermal mass. Error trying to reach 60C on bed, gets to 50, LED goes to flashing rather than constant, then quits. Tried M303 at 50, saved PID parameters, but same problem. Screen reading is 5 or more degrees C LOWER than temp at thermistor (100K, "1"), using optical pyrometer. Which is correct at body temp and at 100C boiling water (I'm at sea level). I've just recompiled using longer timeouts for 2 degree increase (20 seconds to 60), haven't tried it yet.
Resistance of thermistor for bed is CORRECT for temps up to 50C, but displayed temp is low by perhaps 5-7 degrees. Thermistor table (1.h) is identical to that of Marlin 1.x which I was using previously.
Bottom line, displayed temp is in error relative to resistance of thermistor. I'd greatly appreciate any help / thanks /m
Resistance of thermistor for bed is CORRECT for temps up to 50C, but displayed temp is low by perhaps 5-7 degrees. Thermistor table (1.h) is identical to that of Marlin 1.x which I was using previously.
Bottom line, displayed temp is in error relative to resistance of thermistor. I'd greatly appreciate any help / thanks /m