Need help to connect Heated bed to Duet 3



  • Hi everybody

    I don't find what I'm doing wrong...

    I'm trying to connect an heated bed to Duet 3, Thermistor on IO PIN4

    Here is the code :

    M308 S0 P"io4.in" Y"thermistor" A"Bed" T100000 B4138 C0   ; Set thermistor 
    M950 H0 C"bedheat" T0                                      ; Bed heater
    M140 H0                                                    ; Add heater to bed after RRF3.01 RC10
    M143 H0 S120                                               ; Set temperature limit for heater 0 to 120C
    

    I get -271°C on DWC

    I checked the thermistor (about 120k ohm at room temp).

    Thanks by advance



  • you can't use IO's for temperature measurement.
    you need to use a proper temperature input such as temp0



  • Ok, thanks.

    Tried this without success after changing pin sensor to temp0 :

    M308 S0 P"temp0" Y"thermistor" A"Bed" T100000 B4725 C7.06e-8    ; Set thermistor 
    M950 H0 C"bedheat" T0                                      ; Bed heater
    M140 H0                                                    ; Add heater to bed after RRF3.01 RC10
    M143 H0 S100              
    


  • that code looks find to me. I assume you've moved the connection to the temp0 input?



  • Yes I changed to temp0 on board...



  • Hi,

    Where's the M307 command?

    Frederick



  • Fiannly it worked with :

    M308 S0 P"temp0" Y"thermistor" T100000 B4725 C7.06e-8 
    M950 H0 C"out0" T0 ; create heater and map sensor 0
    M140 H0                                                   
    M143 H0 S100                                       
    

    Thanks !



  • @duetlover

    Are you sure that's the correct thermistor for your bed? Also looking at my config.g set up via the online config tool it appears your missing a commands.

    M308 S0 P"temp0" Y"thermistor" A"Keenovo Bed" T100000 B3950           ; configure sensor 0 as thermistor on pin temp0
    M950 H0 C"out0" T0                                     		  		  ; create bed heater output on out0 and map it to sensor 0
    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
    M143 H0 S120                                         		   		  ; set temperature limit for heater 0 to 120C
    

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