Need help to connect Heated bed to Duet 3

duetlover

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

jay_s_uk

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

duetlover

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

jay_s_uk

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

duetlover

Yes I changed to temp0 on board...

fcwilt

Hi,

Where's the M307 command?

Frederick

duetlover

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 !

Rushmere3D

@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