Temperature Probe

Software / Firmware General
#1

I am running Ramps 1.4 with Dual End Stop software.

I am trying to read out a temperature on the LCD or using the M105 command. I figured that it may be as simple as connecting a suitable NTC thermistor to the T0 terminals of the board and assigning probe type:

#define TEMP_SENSOR_0 30

But it didn’t work (LCD still reporting 0degrees on the “hot end”)

So I tried using the software dummy instead to check if thermistor is working ok

#define TEMP_SENSOR_0 998

But still no change in the temperature read out

…has something been turned off in the MarlinBuilder Firmware that I am overlooking? Maybe a pin assignment?

#2

That should only work if EXTRUDERS=1. Maybe there is another way to get a case temperature or plug it into the bed section?

#3

OK that would explain it and since we are using all drivers to facilitate Dual End Stop it would not be sensible to turn on Extruders=1.

Bed Temp or Chamber Temp could be worth investigating (although I don’t think the later will display temp on screen looking at some of the commentary on Github)

2 Likes
#4

Continuing to play with this and enabled the dummy software temp probe as below for debugging
#define TEMP_SENSOR_BED 998

But getting complier error

sketch\src\lcd\menu\menu_temperature.cpp: In function 'void do_preheat_end_m()':

sketch\src\lcd\menu\menu_temperature.cpp:96:29: error: '_preheat_end' was not declared in this scope

   void do_preheat_end_m() { _preheat_end(editable.int8, 0); }

                             ^~~~~~~~~~~~

sketch\src\lcd\menu\menu_temperature.cpp:96:29: note: suggested alternative: '_preheat_bed'

   void do_preheat_end_m() { _preheat_end(editable.int8, 0); }

                             ^~~~~~~~~~~~

                             _preheat_bed

I have run a search for all references of “bed” to see if there is a similar parameter to Extruders=1 to turn back on bed temperature functionalities but nothing jumps out. Strange also as board is BOARD_RAMPS_14_EFB (Extruder Fan Board)

Any thoughts? Where there any changes made to the firmware to turn off the bed?
Cant help but think there is a better way to enable an auxiliary temperature read out.

#5

I don’t see anything about disabling a heated bed in the cnc config, or about enabling it in the mp3dp configs.

#6

Seems to be referencing part of the menu_temperature.cpp as below but I can’t see any mention of HAS_HEATED_BED or HEATED_BED in configs

#if PREHEAT_COUNT

  #if HAS_TEMP_HOTEND
    inline void _preheat_end(const uint8_t m, const uint8_t e) { thermalManager.lcd_preheat(e, m, -1); }
    #if HAS_HEATED_BED
      inline void _preheat_both(const uint8_t m, const uint8_t e) { thermalManager.lcd_preheat(e, m, m); }
    #endif
  #endif
  #if HAS_HEATED_BED
    inline void _preheat_bed(const uint8_t m) { thermalManager.lcd_preheat(-1, -1, m); }
  #endif
#7

It is in Conditionals_post.h. It looks like it is enabled with HEATER_BED. That is defined in the pins file.

#8

Just how did you find that!!??

Still digesting what it means but seems like TEMP_SENSOR_BED cannot be -4,-3,-1 everything else should be ok.

Tried a compile with #define TEMP_SENSOR_BED 1000…still a sad face :frowning:

Suspect I am out of my c+ depth

#9

I used grep.

There are a few set thermistor tables and they each have a number. 10 is not double 5. 10 is just one kind and 5 is another. In my experience, the most common are 11, or 5.