# Thermostat Configuration

This guide walks through the SmartPID on-device configuration screens for setting up a single-channel thermostat, typically used for fermentation temperature control. Access these screens by navigating to **Configuration** on your SmartPID device.

## Configuration Menu

From the main Configuration menu, select **HW setup** to configure the hardware relay assignments for your thermostat.

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## HW Setup -- Control and Heating/Cooling Modes

In the **HW setup** screen, configure the following settings:

* **Control Mode**: Set to **T-static** for standard thermostat operation (maintaining a fixed target temperature).
* **Heating Mode**: Set to **ON/OFF** for relay-based heating control.
* **Cooling Mode**: Set to **ON/OFF** for relay-based cooling control.
* **Multi Control**: Set to **Dual** if you are using both heating and cooling on a single channel.
* **Out1 Heating**: Set to **Relay1** to assign heating output to the first relay.

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## HW Setup -- Relay Assignments and Button Beep

Scroll down in **HW setup** to configure the remaining relay assignments:

* **Out1 Heating**: **Relay1** -- Heating output is assigned to relay 1.
* **Out1 Cooling**: **Relay2** -- Cooling output is assigned to relay 2.
* **Out2 Heating / Out2 Cooling**: Set to **OFF** if you are using a single-channel configuration.
* **Button Beep**: Set to **No** to disable the audible button press beep, or leave enabled as preferred.

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## Process Parameter -- Set Points and Timers

In the **Process parameter** screen, configure the temperature set points and timers:

* **Set-Point 1**: The target temperature for heating (e.g., 55.0). This is the temperature Brewfather will control when a fermentation profile is sent.
* **Set-Point 2**: The target temperature for cooling (e.g., 40.0).
* **Timer 1 / Timer 2**: Duration timers for each set point. Set to **0:00** if you are controlling the profile from Brewfather.
* **PID1 Kp**: The proportional gain for the PID controller (e.g., 15.0). Adjust based on the responsiveness of your heating system.

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## Process Parameter -- PID Tuning and Hysteresis

Scroll down in **Process parameter** for additional PID tuning settings:

* **PID1 Kd**: The derivative gain (e.g., 0.0). Helps reduce temperature overshoot.
* **Hysteresis 1**: The temperature band around the set point before the controller activates (e.g., 0.3). A smaller value provides tighter control but more frequent relay cycling.
* **Reset DT 1**: Derivative reset time (e.g., 5.0).
* **Fridge Delay 1**: Compressor delay in minutes (e.g., 3). Protects refrigeration compressors by preventing rapid on/off cycling.
* **PID2 Kp**: Proportional gain for the second PID channel (e.g., 15.0), used if you have a dual-channel setup.

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## Related docs

* [SmartPID](https://docs.brewfather.app/integrations/smartpid)
* [Devices](https://docs.brewfather.app/devices)