MCU / PCB Cooling Duet 3



  • Is it possible to set up a fan on the Duet 3 as per the Duet 2 for cooling the PCB / MCU / etc etc.

    This is what I planned based on posts elsewhere, it results in no errors but the fan does not appear in the web gui. I'll verify if the fan runs once somebody validates my proposed wiring.

    M950 F2 C"out9" Q500		; create fan 2 on pin out9 - figure out frequency rqd	
    M106 P2 H"mcu-temp" T45:55 I1 L0.3 ; set Duet cooling fan	
    
    

    I also plan to wire to out9 as per the diagram below - anyone see any issue - fan will be a Noctua 120mm NF A12 max 140ma. I've moved jumper for out7 to 9 accordingly and intend to put a lighting enable relay on OUT4 (24V DC relay -Omron LY4N - 69ma coil) for now.

    Fan.png

    addendum - can't use out4 to 6 as I have 24V DC fans on out4 and out5.


  • administrators

    You need to create the mcutemp sensor using M308, then refer to that sensor number in the M106 H parameter.

    I suggest you put your 24V fans on OUT7 to OUT9 so that you can put the 12V PWM fan on one of OUT4 to OUT6. Don't forget to set the fan voltage jumpers correctly.



  • Do you need any 'thermistor' definition etc or simply

    M308 S3 P"mcutemp"

    Which seems to have been accepted, 12V fan now on OUT4 but doesn't appear at all on the web pages anywhere ....

    are out7 to 9 volts i.e. via a DAC or PWM - tried the 24's on there and they're not moving (yes I switched the jumper to 'fused')

    I actually intend to run the fans via a DAC as the 24V fans are both straight DC fans but I'm just trying to get my head around all the configuration (since the DAC's aren't built yet).



  • Nah - just keep getting sensor does not exist it doesn't matter whether I use mcu-temp or mcutemp the error is M308: Unknown pin name


  • administrators

    @Garfield said in MCU / PCB Cooling Duet 3:

    M308 S3 P"mcutemp"

    "mcutemp" is the type of the sensor, not a pin name. So you need:

    M308 S3 Y"mcutemp"



  • @dc42 said in MCU / PCB Cooling Duet 3:

    M308 S3 Y"mcutemp"

    Thanks you ... I maybe need to make a few notes to help the documentation process ... may as well add some value back.



  • Tell me - apart from everything what should I be reading to get to know the 'parameters' given that the bulk of docs so far are really aimed at the Duet 2

    So Fan on OUT4 configured as follows

    M308 S3 Y"mcu-temp"
    M950 F2 C"out4" A"MCU" Q25000	      ; create fan 2 on pin out4 - figure out frequency rqd	
    M106 P2 H3 T30:40 I1 L0.3	      ; set Duet cooling fan	
    

    even though the MCU is at 37°C the fan doesn't run

    using this

    M308 S3 Y"mcu-temp"
    M950 F2 C"out4" A"MCU" Q25000	      ; create fan 2 on pin out4 - figure out frequency rqd	
    M106 P2 H3 T45:55 I1 L0.3	      ; set Duet cooling fan	
    

    the fan runs pretty much flat out but the MCU is well below 45°C

    inverting makes no difference as in

    M308 S3 Y"mcu-temp"
    M950 F2 C"out4" A"MCU" Q25000	      ; create fan 2 on pin out4 - figure out frequency rqd	
    M106 P2 H3 T45:55 L0.3	      ; set Duet cooling fan	
    

    Does it make a difference that the fan expects the PWM to be logic level 5V DC.

    and despite having 3 fans defined only FAN0 appears on the web pages.



  • Answer - L0.3 is way too high for the Noctua NF-A12, the noctua supports being turned off via PWM.

    My code is also incorrect - needs to be S3 and I've also added H-1, I've set L0.3 down to L0.1 but the system doesn't seem to like being less than that as it does nothing.

    EDIT >>>

    I take it back - the L number is having little or no effect ..... neither is H so I can't make it turn off below 'setpoint' - this has to be PWM / fan combination related but it isn't following any of the 'Intel' specs for PWM as I understand them - may need to fire the scope up .....


  • administrators

    @Garfield said in MCU / PCB Cooling Duet 3:

    using this
    M308 S3 Y"mcu-temp"
    M950 F2 C"out4" A"MCU" Q25000 ; create fan 2 on pin out4 - figure out frequency rqd
    M106 P2 H3 T45:55 I1 L0.3 ; set Duet cooling fan

    the fan runs pretty much flat out but the MCU is well below 45°C

    The I1 parameter is no longer supported in M106. Remove it and use pin "!out4" in the M950 command. To enable the tacho reading too, use "!out4+out4.tach".


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