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RPI-GPIO-fan-temp-control-of-external-HDD-enclosure.md

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+# 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
+```
+
+---
+
+## 📂 File Structure
+
+
+---
+
+## 📌 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`
+