Bigtree Tech SKR 1.3 Fan configuration

I'm running a SKR1.3 with Marlin 2.x, I can't seem to get the part cooling fan configured correctly. I have a PWM mosfet connected to pin 1.26 as the trigger.

In my configuration_adv.h file, I have the Part cooling fan set as

#define FANMUX0_PIN P1_26 //-1
#define FANMUX1_PIN -1
#define FANMUX2_PIN -1

However when you run M43, the pin debugging commad you see that it does not know that the pin has that assignment. I have no way of controlling the fan. the fan does come on but it's not controlled. I need to slow it down. As it's too fast and cooling the heater block too much.

Recv: PIN: 1.26 Output = 0

Firstly I can replicate these results.

But the issue is that the debug pins doesn't show FANMUX pins...

in pinsDebug_list.h find

#if PIN_EXISTS(FAN3)
  REPORT_NAME_DIGITAL(__LINE__, FAN3_PIN)
#endif

chnage it to

#if PIN_EXISTS(FAN3)
  REPORT_NAME_DIGITAL(__LINE__, FAN3_PIN)
#endif
#if PIN_EXISTS(FANMUX0)
  REPORT_NAME_DIGITAL(__LINE__, FANMUX0_PIN)
#endif

Its now shows as expected with M43

SENDING:M43 P126
PIN: 1.26        FANMUX0_PIN                            Output = 0

So what ever issue your really looking for, it probably isnt here...

I suspect FANMUX is not what you think it is.

What are you trying to achieve?

Edited 4 time(s). Last edit at 10/28/2019 04:06AM by Dust.

So, my printer has a dual extruder setup.

HE0 connected to pin 2.7
HE1 connected to pin 2.4

HE0 fan connected to pin 2.3
HE1 fan is connected via a MOSFET triggering using Pin 1.28

I would like to add a part cooling fan that is controlled via the parameters in the slicer. I connected a fan using a MOSFET again and define pin 1.26 in the FANMUX section.


Should the part cooler be connected to Pin 2.3 and the HE0 fan be conned to pin 1.26??


I was under the impression that the FANMUX was where you defined the channels for multiplexing fan control but since I don't have a multiplexer installed. The firmeware does not know what to do with it. The comments do say "Set FANMUX[012]_PINs below for up to 2, 4, or 8 multiplexed fans." and I'm only using one channel (pin) it's not the correct use case.

I guess my real question is, where do I define the part cooling fan pins?

Something is off with your description.

You have two hot end heater pins
HEATER_0_PIN connected to pin 2.7
HEATER_1_PIN connected to pin 2.4

FAN_PIN and FAN1_PIN are the gcode controlled part cooling fans.

Marlin controlled extruder cooling fans are defined in Configuration_adv.h (turns on when hot end is warmer than 50c)
ie update these
#define E0_AUTO_FAN_PIN -1
#define E1_AUTO_FAN_PIN -1

FAN_PIN and FAN1_PIN fans are defined in your pins files
in Marlin/src/pins/lpc1768/pins_BIGTREE_SKR_V1.3.h

the code looks like (with some comment added)

//
// Heaters / Fans
//
#ifndef HEATER_0_PIN
  #define HEATER_0_PIN     P2_07       //yes do this
#endif
#if HOTENDS == 1                                //not in your case, so ignore this and do the else
  #ifndef FAN1_PIN
    #define FAN1_PIN       P2_04
  #endif
#else                                                      //this else is run.
  #ifndef HEATER_1_PIN
    #define HEATER_1_PIN   P2_04
  #endif
#endif
#ifndef FAN_PIN
  #define FAN_PIN          P2_03             //yes do this
#endif
#ifndef HEATER_BED_PIN
  #define HEATER_BED_PIN   P2_05   //yest do this
#endif

add after this

#ifndef FAN1_PIN
  #define FAN1_PIN          P1_28
#endif

FANMUX is either on or off.... Needs extra logic ... not for this.

Edited 1 time(s). Last edit at 10/28/2019 09:07AM by Dust.

Dust, thank you for your help. I think I have it sorted.


TLR in a dual extruder set up with a part cooling fan, you need to move the part cooling fan to the CNC fan pin and add two additional MOSFETS OR use the same signal pin for both fans and reduce some of the wiring and additional boards and not consume a PIN.

This is what I changed.

#define E0_AUTO_FAN_PIN  P1_26 //-1
#define E1_AUTO_FAN_PIN  P1_28 //-1

I moved the fans around. I have configured the Hotend fans to be controlled by the external MOSFET's and I put the Part cooling fan on the CNC fan pin. It all works as it should now. I may try adding the logic you suggested.

I left the Pins file alone.

// Heaters / Fans
//
#define HEATER_0_PIN       P2_07
#if HOTENDS == 1
  #define FAN1_PIN         P2_04
#else
  #define HEATER_1_PIN     P2_04
#endif
#define FAN_PIN            P2_03
#define HEATER_BED_PIN     P2_05

I may just assign the same pin for both extruder fans so I can save a pin