Passive heating

I have a BTT SKR 2 with a TFT35 E3 V3 screen

The TFT firmware is set up like this;

#### Heated Chamber Support
# Enable/disable presence of heated chamber.
#
# NOTE: Disable it to let the TFT auto-detect if chamber heating is enabled in Marlin firmware.
#
# Options: [disable: 0, enable: 1]
heated_chamber:0

I am trying to set up a a passive chamber heat system with a chamber fan in my build box.
with the printer heat sources powered down the chamber resides at about 26C

I can see the chamber temp on the TFT (it changes as expected with heat in the chamber)
When I set a heat value of 6C or above, the fan comes on immediately. [seems to be the minimum power needed for fan start up, if the fan is being powered by heater supply]

when the heat temp is set below the chamber temp the fan comes on.
when the heat temp is set at or near chamber temp [+, - 1 degree C) the fan pulses.
when the heat temp is set above chamber temp the fan comes on.


the heater signal pin is PB4 [hot end 1 signal out] I have left the socket empty
the thermistor signal pin is PA3 [thermistor hot end 1 socket] I have plugged in a thermistor here



One more observation:

Before I started this I had access to all three fans from my fan menu.[Fan0 - part fan, Fan 1 - extruder fan, Fan2 - chamber fan]
Fan2 no longer responds from the fan menu, but it still works thermostatically as the extruder comes up to temp.

Does anyone know how to properly configure MARLIN to accomplish this? Or can anyone see how I monkeyed up what I am trying to configure?


I have configured MARLIN 2.1.2.1 like this;


Configuration.h

#define TEMP_SENSOR_1 1
#define TEMP_SENSOR_CHAMBER 1


Pins_BTT_SKR_V2_0_common.h [un-altered values]

#define TEMP_CHAMBER_PIN TEMP_1_PIN
#define TEMP_1_PIN PA3 // TH1 [thermistor hot end 1 socket]
I have a thermistor plugged in to PA3


//#define PIDTEMPCHAMBER
//#define CHAMBER_LIMIT_SWITCHING
I have left both commented out [am trying to use BAM-BAM]

Configuration_adv.h

#define CHAMBER_CHECK_INTERVAL 5000
#define CHAMBER_HYSTERESIS 2

#define HEATER_CHAMBER_PIN PB4 (SKR 2 extruder1 socket)
I have not plugged a heater element into PB4

//#define HEATER_CHAMBER_INVERTING false
//#define FAN1_PIN -1
#define CHAMBER_FAN
#define CHAMBER_FAN_INDEX 2 // Index of a fan to repurpose as the chamber fan. (Default: first unused fan)
#define CHAMBER_FAN_MODE 2
#elif CHAMBER_FAN_MODE 2
#define CHAMBER_FAN_BASE 128
#define CHAMBER_FAN_FACTOR 25
#define THERMAL_PROTECTION_CHAMBER_PERIOD 20 // Seconds
#define THERMAL_PROTECTION_CHAMBER_HYSTERESIS 2 // Degrees Celsius
#define WATCH_CHAMBER_TEMP_PERIOD 60 // Seconds
#define WATCH_CHAMBER_TEMP_INCREASE 2 // Degrees Celsius

Edited 1 time(s). Last edit at 08/06/2023 11:59AM by Mr Kroll.

Sorry, apparently I buried my question in the text above. So here it is;

Does anyone know how to properly configure MARLIN to accomplish this? Or can anyone see how I monkeyed up what I am trying to configure?

Thank you in advance, Shane

... why burden Marlin? -- you can install a separate temp.-controller ...

---

Viktor
--------
Aufruf zum Projekt "Müll-freie Meere" - [reprap.org] -- Deutsche Facebook-Gruppe - [www.facebook.com]

Call for the project "garbage-free seas" - [reprap.org]

I have an STC-1000 Temp controller. (about $10.00 US) It was to be the back up plan.

It seemed to me setting it up through the controller & MARLIN allowed a little easier adjustment,
including temp control in the preheat menus.

Thanks, Shane

Edited 1 time(s). Last edit at 08/11/2023 04:05PM by Mr Kroll.

Please attach your pins_BTT_SKR_V2_0_REV_B.h file.

Here it is, thanks in advance, Shane

The Rev_B file supersedes to the common.h file

You've given Marlin control of the chamber fan when you enabled CHAMBER_FAN. Because it is no longer under user control it won't show up in the FAN menu.

Same thing is true for fans assigned to one of the AUTO_FAN functions.

Thanks for all the help guys. Here are a couple of pics of the installed controller. - Shane