Raspberry Fan-Check

This repository contains an explanation to implement a simple fan check system that toggles a fan on RaspberryPI 4 via GPIO Pins

Getting Started

• Needed: Transistor (to connect power when GPIO Pin sends signal), Board, LED (optional), Resistor (see image below)
• Click here for conversion table
• The red cable is connected to the 5V (+) (also 3.3V possible for slower speed) and the blue cable to the Ground (-)
• In this script, GPIO PIN 11 is used. When the pin is enabled, it sends a signal (brown cable) to the LED which gets forwarded to the Transistor.
• The Transistor then receives the signal and forwards the power through the black cable to the fan which toggles it
• Software: Python3 & pip

Execution of temp check on every boot

• python3 temp.py is the main script -> Remove file ending, it is executable without python3 command due to #!/usr/bin/env/python3
• Script must be moved to /usr/local/bin to be executable by simply writing the filename in the terminal.

How to

• sudo chmod +x /usr/local/bin/<FILENAME>.py - Add execution permission
• sudo mv <FILENAME>.py /usr/local/bin/<FILENAME>

⚠️ Hint: You can also just move the deploytemp.py script with this instruction, then execute it by typing deploytemp and insert the name (one at a time) of the files you want to move. (Check if files are encoded in LF!)

• To start the script on boot of Raspberry Pi:
  • Create temp.sh script from repo
  • Move it to /etc/init.d and make it executable
    • sudo mv temp.sh /etc/init.d/
    • sudo chmod +x /etc/init.d/temp.sh
  • Register script to be executed on boot:
    • sudo update-rc.d temp.sh defaults
  • Reboot RaspberryPi or manuelly start the script:
    • sudo /etc/init.d/temp.sh start

⚠️ Files that are moved to /usr/local/bin must be encoded in LF, not CRLF, otherwise they are not executable. Fix (VSCode): At the bottom right, change CRLF to LF Fix (Terminal): sudo sed -i -e 's/\r$//' /PATH/FILENAME

Scripts explanations

• deploytemp.py - Automatically changes the file ending of the inserted script, moves it to /usr/local/bin and makes it executable
  • Firstly move the file to /usr/local/bin, remove the file ending, check if LF is used and add +x permission
  • Then execute it with deploytemp (The files to move must be in the same directory)
• disablefan.py & enablefan.py - Toggles fan (e.g. for debugging purposes)
• temp.py - Main Script -> Fan-Check
• temp.sh - Bootscript of temp.py
• disabletempcheck.py - Fully disables temperature check. Can only be reenabled by rebooting
• checktemp.py - Displays temperature every few seconds (stop with ctrl + c) [Needs: apt install python3-colorama]
• test_led.py - Tests the LED of the board. The GPIO-PIN must be correct

How To

(https://www.elektronik-kompendium.de/sites/raspberry-pi/bilder/raspberry-pi-gpio.png)