I am in the process of buttoning up a Nitehawk conversion on my Voron. I also replaced my extruder thermistor with an OE replacement purchased from a reputable vendor.
Post setup, my heated bed is reading spot on (it’s 18.3 C in my basement aka 65 F). I verified that my extruder is also at ambient temperature by wedging a Thermapen under its silicone sock and letting it acclimate for 10 minutes. The I’m not sure why the extruder would be reading high.
I bought a spare thermistor and wired it in. The result was identical.
Thoughts? Ideas? I’m pretty sure I have the Nitehawk and thermistor set up correctly.
[extruder]
step_pin: nhk:gpio23
dir_pin: nhk:gpio24
enable_pin: !nhk:gpio25
heater_pin: nhk:gpio9
sensor_pin: nhk:gpio29
pullup_resistor: 2200
sensor_type: ATC Semitec 104NT-4-R025H42G`
Thanks for the point of reference. Any idea what extruder and thermistor you have?
I measured my thermistor’s resistance when cold at 183 k ohms. This jives pretty well with the expected value per the data sheet. With the 2.2k ohm pullup resistor, this puts the A2D with 98.92 percent of Vref.
I tested against a known hot source (165 °F) and the printer reported the correct value. The resistance at this value is a lot lower. I suspect the NH’s A2D is slightly non-linear at the extremes of its range, which is fairly normal.