Adding A Third Temperature Sensor



  • I am making an Extruder and want to use a PT1000 to measure heat creep in the heat sink with different fans/heat sink designs. IF I connect the PT1000 to E1 on the Duet board how do I change the config file so I can see all three temperatures, bed, extruder and heat sink?

    Broad is a Duet 2 WIFI running 3.0 firmware.

    From current config file:
    ; Heaters
    M308 S0 P"bedtemp" Y"thermistor" T100000 B4725 C7.06e-8 ; configure sensor 0 as thermistor on pin bedtemp
    M950 H0 C"bedheat" T0 ; create bed heater output on bedheat and map it to sensor 0
    M143 H0 S130 ; set temperature limit for heater 0 to 130C
    M307 H0 B0 S1.00 ; disable bang-bang mode for the bed heater and set PWM limit
    M140 H0 ; map heated bed to heater 0
    M308 S1 P"e0temp" Y"thermistor" T100000 B4725 C7.06e-8 ; configure sensor 1 as thermistor on pin e0temp
    M950 H1 C"e0heat" T1 ; create nozzle heater output on e0heat and map it to sensor 1
    M143 H1 S275 ; set temperature limit for heater 1 to 275C
    M307 H1 B0 S1.00 ; disable bang-bang mode for heater and set PWM limit


  • administrators

    Use another M308 command to define the 3rd sensor. If you give it a name using the A parameter, you will be able to show it in DWC.



  • I add the line below but it looks like it is reading 2000C. How do I fix this?

    M308 S2 P"e1temp" Y"pt1000" A"Heat Sink"
    f7bc9b18-8156-41fa-a53e-8f83e6b6c447-image.png


  • administrators

    That reading suggests that the PT1000 isn't connected.



  • I checked the resistance and it is 95K at room temperature. It is plugged into the connector next to the heater block.


  • administrators

    @Keith53 said in Adding A Third Temperature Sensor:

    I checked the resistance and it is 95K at room temperature.

    In that case it's a 100K thermistor, not a PT1000.



  • I changed it to M308 S2 P"e1temp" Y"thermistor" A"Heat Sink" and it works now. Wonder why E3D calls it a PT1000?

    Is there a way to get it to show up with Tool 0 and Bed so I do not need to push the "Extra" button to see the temp?
    a4b9ab12-ce42-42af-a86c-2042e1a2bff9-image.png


  • administrators

    @Keith53 said in Adding A Third Temperature Sensor:

    Wonder why E3D calls it a PT1000?

    If you ordered a PT1000, maybe they shipped you the wrong part?

    @Keith53 said in Adding A Third Temperature Sensor:

    Is there a way to get it to show up with Tool 0 and Bed so I do not need to push the "Extra" button to see the temp?

    At present, only by creating a dummy heater that uses sensor 2 and a dummy tool that uses the dummy heater.


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