Questions about MKS 1.4 & 100K Resistor

[3DStyle]

Hi guys,

I made a terrible mistake and burnt my Arduino Mega 2560 and RAMPS 1.4 boards on the R-CNC.
Don't have the time to wait for the new boards I bought from Aliexpress. I have laying around a
MKS Gen 1.4 board which I want to use until I'll receive the boards that I ordered.

1. Is that okay to use the MKS Gen 1.4 with the R-CNC?
2. What is the use of the 100K resistor in the R-CNC? Do you have an idea where I should connect it to on the MKS Gen 1.4 board?



I'll appreciate any kind of help!
Thanks.

[RoMaker]

Hi 3Dstyle !

You can not use this board instead Ramps besause on the MKS 1.4 the drivers are integrated and you can not plug "step" and "dir" wires

[3DStyle]

Hi RoMaker, thanks for your answer!

My bad, I have the MKS Gen v1.4, which does have ports for external motor drivers.
I have this one:



I just wonder where should I connect the 100K resistor in this board, and what is the purpose of it?

Thanks!

[Aze]

Hi,
you plug it to the E0 thermistor. It's just because there's a thermal control in the firmware (it's for 3D printers: if there is no thermal resistor, the firmware stops). In fact you can desactivate this somewhere in the firmware, but you have to search on google, I can't help you (and it's faster to just plug a resistor).

[3DStyle]

Thank you very much Aze!

So basically the 100K resistor pretends to be a "heated nozzle", correct?

[Kachidoki]

I checked quickly into the Repetier code, it seems that replacing:

Code : Tout sélectionner

#define EXT0_TEMPSENSOR_TYPE 1

by:

Code : Tout sélectionner

#define EXT0_TEMPSENSOR_TYPE 0

should disable the thermistor and assume a fixed temperature of 25°C.
I have not tested myself but if it can help.

[Aze]

So basically the 100K resistor pretends to be a "heated nozzle", correct?

It pretends to be a thermal resistor but yes, it's a bit like a "heated nozzle" if you want. The firmware just check if there is a value on the thermistor (100kohm, 2ohm, 100000kohm, everything but not infinity) otherwise it means than the thermal resistor is broken (it's a brittle component) and your house could burn

[3DStyle]

Thanks guys, it works great!