PT100 Daughterboard Duet 3

  • Seems either I can't read or am terminally dumb but copying the examples from the documentation isn't working on my Duet 3.

    this command

    M308 S2 P"3.spi.cs0" Y" rtd-max31865"

    Results in an error

    Error: Response Timeout: CAN Addr 3, req type 6011

    This is preceded by a "Timeout while: waiting for transfer ready pin"

    Is this related to the use of a RPi - because it uses SPI also I think - what determines SPI addresses.

  • Moderator

    @Garfield How is the PT100 connected? I don't think you need the '3.' on the front of the P parameter. That would be for the 3rd expansion board. Assuming it's on the Duet 3, RRF config tool gives:

    ; Heaters
    M308 S0 P"spi.cs0" Y"rtd-max31865"      ; configure sensor 0 as thermocouple via CS pin spi.cs0
    M950 H0 C"out1" T0                      ; create bed heater output on out1 and map it to sensor 0
    M143 H0 S120                            ; set temperature limit for heater 0 to 120C
    M307 H0 B1 S1.00                        ; enable bang-bang mode for the bed heater and set PWM limit
    M140 H0                                 ; map heated bed to heater 0
    M308 S1 P"spi.cs1" Y"rtd-max31865"      ; configure sensor 1 as thermocouple via CS pin spi.cs1
    M950 H1 C"out2" T1                      ; create nozzle heater output on out2 and map it to sensor 1
    M143 H1 S280                            ; set temperature limit for heater 1 to 280C
    M307 H1 B0 S1.00                        ; disable bang-bang mode for heater  and set PWM limit


  • Throws no error .... but if I don't apply the sensor to the extruder or bed they aren't visible ... I shouldn't need to allocate them to anything to see values from them ... I can see my Pinda temperature sensor just fine as an 'extra' ....

  • administrators

    @Garfield, which board is the PT100 daughter board mounted on?

  • @dc42 Direct on the Duet 3 using the little nylon standoff. Currently have a resistor and a PT100 connected just for testing. I can see no values from them in the web portal unless I map them to heaters. I was hoping that they would show up as extras whilst testing but it seems not.

  • Moderator

    @Garfield Give it a name using the 'A' parameter (see M308 in the gcode dictionary), and it will show in the DWC under the 'Extras' part of 'Tools and Extras'. eg:

    M308 S2 P"spi.cs0" Y"rtd-max31865" A"PT100"

    Sending something similar on my Duet Wifi (M308 S2 P"spi.cs1" Y"rtd-max31865" A"PT100" in my case) gives this:
    I also get "Error: Failed to initialise RTD: bad response from sensor" in the console when I send the command, but then I don't have a PT100 daughterboard connected!


  • Well I'll be - they appeared - never even gave that a thought although I'd named the Pinda sensor so it was there - it never occured that the name was the trigger to get it displayed.

    Learning something every day ...

  • Moderator

    @Garfield You're welcome!


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