Setting Extruder temperature to 300C causes emergency shutdown

[synman]

@michytka

I'm able to (easily) recreate the issue you reported here: #16 (comment)

I will provide updates within this issue.

Recv: Error:MAXTEMP triggered, system stopped! Heater_ID: E0
Recv: 
Recv: echo:Home XYZ First
Recv: //action:notification Home XYZ First
Recv: echo:Err: MAXTEMP
Recv: Error:Printer halted. kill() called!

[synman]

Some more details on this error. It is coming from the raw max value which is an extrapolated value. I think I just need to give it some wiggle room and this will be fixed.

Recv:  T:297.70 /300.00 (95.69) B:16.37 /0.00 (3963.25) @:74 B@:0
Recv:  T:298.52 /300.00 (94.37) B:16.39 /0.00 (3963.13) @:67 B@:0
Recv: HOTEND RAW MAXTEMP E:0 T:1499 MAX:1504
Recv: Error:MAXTEMP triggered, system stopped! Heater_ID: E0
Recv: 
Recv:  T:298.95 /0.00 (93.69) B:16.36 /0.00 (3963.31) @:0 B@:0
Recv:  T:298.95 /0.00 (93.69) B:16.36 /0.00 (3963.31) @:0 B@:0
[...]
Recv: echo:Err: MAXTEMP
Recv: Error:Printer halted. kill() called!

@michytka you must share with me what filament you are trying to melt at 300C!

[synman]

Here's why this is failing. Creality tweaked the primary thermistor table..... It looks like they needed to rescale the table to accommodate a max extruder temperature of 320C

In Creality S1 Pro code
https://github.com/CrealityOfficial/Ender-3S1/blob/s1_pro/Marlin/src/module/thermistor/thermistor_1.h

In Marlin
https://github.com/MarlinFirmware/Marlin/blob/2.0.8/Marlin/src/module/thermistor/thermistor_1.h

I'm going to go with the Creality table, but if your machine catches on fire and burns down your house, it's on Creality, not me.

[synman]

this is now fixed in all builds -- was previously broken in bugfix-2.1.x and 2.1.2