# Raspberry Pi Fan Control Script

This Python script monitors the temperature of a Raspberry Pi using a 1-Wire digital temperature sensor (e.g., DS18B20) and controls a connected fan via GPIO. It is designed to help maintain optimal operating temperatures by automatically turning the fan on or off depending on the measured temperature.

---

## 🛠️ Features

- Reads temperature data from a 1-Wire sensor (`DS18B20`)
- Uses GPIO pin control to activate/deactivate a fan
- Customizable temperature thresholds for fan activation
- Simple, lightweight script suitable for cron jobs or long-running processes

---

## 💡 How It Works

1. The script accesses the DS18B20 sensor data from the Linux 1-Wire interface (`/sys/bus/w1/devices/`).
2. It parses the temperature output and converts it to degrees Celsius.
3. Based on the temperature:
   - If `≥ 46°C`, the fan is turned **on**
   - If `≤ 40°C`, the fan is turned **off**
4. GPIO pin 18 is used to control the fan via the `pinctrl` utility.

---

## 📌 Prerequisites

- Raspberry Pi (any model with GPIO and 1-Wire support)
- 1-Wire temperature sensor (e.g., DS18B20) connected and configured
- GPIO fan connected to pin 18 (can be changed in script)
- `pinctrl` utility installed and configured
- Python 3

Enable the 1-Wire interface on the Pi using `raspi-config` or by adding this line to `/boot/config.txt`:

```bash
dtoverlay=w1-gpio
```
Then reboot:

```bash
sudo reboot
```

## 📄 Usage

1. Make sure the sensor is connected and recognized under `/sys/bus/w1/devices/`.

2. Update the `device_folder` variable if your sensor ID differs from the one in the script:

   ```python
   device_folder = glob.glob(base_dir + '28-*')[0]
   ```

The script will continuously monitor the temperature and control the fan accordingly.

---

## ⚙️ Customization

- **Temperature thresholds**: Modify the values in the `if` / `elif` block to change when the fan turns on/off.
- **GPIO pin**: Change the pin number in `pinctrl set 18 ...` if using a different GPIO.

---

## 🧪 Example Output

```text
Temperature: 41.25 °C  
Temperature: 43.12 °C  
Temperature: 46.05 °C  # Fan turns on here  
Temperature: 39.80 °C  # Fan turns off here
```

---

## 📌 Note

This script uses `pinctrl`, which may not be installed on all systems by default. You may need to substitute `pinctrl` with another GPIO control utility such as:

- `raspi-gpio`
- `gpio` (from WiringPi)
- Python libraries like `RPi.GPIO` or `gpiozero`