# Chamber Temperature Control

OrcaSlicer use `M141/M191` command to control active chamber heater.

If `Activate temperature control` is checked, OrcaSlicer will insert `M191` command at the beginning of the gcode(before `Machine G-code`).

![image](./images/activate_chamber_heater.jpg)

> [!NOTE]
> If the machine is equipped with an auxiliary fan, OrcaSlicer will automatically activate the fan during the heating period to help circulate air in the chamber.

## Using Chamber Temperature Variables in Machine G-code

You can use chamber temperature variables in your `Machine G-code` to control the chamber temperature manually, if desired:

- To set the chamber temperature to the value specified for the first filament:
  ```gcode
  M191 S{chamber_temperature[0]}
  ```
- To set the chamber temperature to the highest value specified across all filaments:
  ```gcode
  M191 S{overall_chamber_temperature}
  ```

## Klipper

If you are using Klipper, you can define these macros to control the active chamber heater.
Bellow is a reference configuration for Klipper.

> [!Important]
> Don't forget to change the pin name/values to the actual values you are using in the configuration.

```gcode
[heater_generic chamber_heater]
heater_pin:PB10
max_power:1.0
# Orca note: here the temperature sensor should be the sensor you are using for chamber temperature, not the PTC sensor
sensor_type:NTC 100K MGB18-104F39050L32
sensor_pin:PA1
control = pid
pid_Kp = 63.418
pid_ki = 0.960
pid_kd = 1244.716
min_temp:0
max_temp:70

[gcode_macro M141]
gcode:
    SET_HEATER_TEMPERATURE HEATER=chamber_heater TARGET={params.S|default(0)}

[gcode_macro M191]
gcode:
    {% set s = params.S|float %}
    {% if s == 0 %}
        # If target temperature is 0, do nothing
        M117 Chamber heating cancelled
    {% else %}
        SET_HEATER_TEMPERATURE HEATER=chamber_heater TARGET={s}
        # Orca: uncomment the following line if you want to use heat bed to assist chamber heating
        # M140 S100
        TEMPERATURE_WAIT SENSOR="heater_generic chamber_heater" MINIMUM={s-1} MAXIMUM={s+1}
        M117 Chamber at target temperature
    {% endif %}
```